/*
|
* The contents of this file are subject to the terms of the Common Development and
|
* Distribution License (the License). You may not use this file except in compliance with the
|
* License.
|
*
|
* You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
|
* specific language governing permission and limitations under the License.
|
*
|
* When distributing Covered Software, include this CDDL Header Notice in each file and include
|
* the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
|
* Header, with the fields enclosed by brackets [] replaced by your own identifying
|
* information: "Portions Copyright [year] [name of copyright owner]".
|
*
|
* Copyright 2024-2026 3A Systems, LLC.
|
*/
|
package org.opends.server.backends.jdbc;
|
|
import com.github.benmanes.caffeine.cache.Caffeine;
|
import com.github.benmanes.caffeine.cache.LoadingCache;
|
|
import org.forgerock.i18n.LocalizableMessage;
|
import org.forgerock.i18n.slf4j.LocalizedLogger;
|
import org.forgerock.opendj.config.server.ConfigChangeResult;
|
import org.forgerock.opendj.config.server.ConfigException;
|
import org.forgerock.opendj.config.server.ConfigurationChangeListener;
|
import org.forgerock.opendj.ldap.ByteSequence;
|
import org.forgerock.opendj.ldap.ByteString;
|
import org.forgerock.opendj.server.config.server.JDBCBackendCfg;
|
import org.opends.server.backends.pluggable.spi.*;
|
import org.opends.server.core.ServerContext;
|
import org.opends.server.types.BackupConfig;
|
import org.opends.server.types.BackupDirectory;
|
import org.opends.server.types.DirectoryException;
|
import org.opends.server.types.RestoreConfig;
|
import org.opends.server.util.BackupManager;
|
|
import java.io.Closeable;
|
import java.nio.ByteBuffer;
|
import java.security.MessageDigest;
|
import java.security.NoSuchAlgorithmException;
|
import java.sql.*;
|
import java.util.*;
|
import java.util.concurrent.ConcurrentHashMap;
|
import java.util.concurrent.Executor;
|
import java.util.concurrent.atomic.AtomicBoolean;
|
import java.util.function.Predicate;
|
|
import static org.opends.server.backends.pluggable.spi.StorageUtils.addErrorMessage;
|
import static org.opends.server.util.StaticUtils.stackTraceToSingleLineString;
|
|
public class JDBCStorage implements org.opends.server.backends.pluggable.spi.Storage, ConfigurationChangeListener<JDBCBackendCfg>{
|
|
private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();
|
|
/** Number of attempts a {@link #write} makes before it propagates the conflict to the caller. */
|
private static final int MAX_RETRIES = 10;
|
|
/**
|
* Wall-clock budget the replays of a {@link #write} may spend, in nanoseconds. It is checked between attempts,
|
* so an attempt already running is never interrupted: the loop returns after at most this window plus one
|
* attempt. It bounds the conflicts that are slow to report, which {@link #MAX_RETRIES} alone does not - MySQL
|
* reports a lock wait timeout only after innodb_lock_wait_timeout, 50 s by default and not overridden here, so
|
* ten attempts would park a worker thread for eight minutes where a single one released it after 50 s. The
|
* deadlocks this retry exists for keep their full attempt budget, since every engine reports one in well under
|
* a second.
|
*/
|
private static final long MAX_RETRY_WINDOW_NANOS = 10L * 1000L * 1000L * 1000L; //10 s
|
|
/** Upper bound of the random delay before the second attempt, in milliseconds; it doubles with every attempt. */
|
private static final double BASE_SLEEP_ON_RETRY_MS = 50.0;
|
|
/** Upper bound the doubled delay is capped at, in milliseconds. */
|
private static final double MAX_SLEEP_ON_RETRY_MS = 1000.0;
|
|
/**
|
* Number of links walked when classifying a failure, also a guard against a chain long enough to matter. One
|
* number for three chains at once - the causes, the next exceptions and the suppressed exceptions are walked
|
* together and counted together - so it is set well above the depth a wrapped failure of this backend reaches:
|
* mssql-jdbc chains every error of one message it received through {@code setNextException}, and a budget spent
|
* on those would never reach the cause the wrapper carries.
|
*/
|
private static final int MAX_CHAIN_LINKS = 64;
|
|
/** The budget of {@link #failureScope}, which walks to the end of the chains: see the comment above it. */
|
private static final int EVERY_LINK = Integer.MAX_VALUE;
|
|
/** SQL Server error number of the transaction picked as the deadlock victim: "Rerun the transaction". */
|
private static final int MSSQL_DEADLOCK_VICTIM = 1205;
|
|
/** Oracle error number of a detected deadlock: ORA-00060, reported with SQLState 61000 rather than class 40. */
|
private static final int ORACLE_DEADLOCK_DETECTED = 60;
|
|
/**
|
* Class 40 states that are transaction rollbacks but must not be replayed. 40003 leaves the outcome of the
|
* transaction unknown, so replaying an add that in fact committed would answer the client with
|
* "entry already exists", and 40002 is an integrity constraint violation, which a replay repeats rather than
|
* resolves. Neither is reachable with the drivers shipped here - of class 40, Connector/J emits only 40000 and
|
* 40001, Oracle only ORA-02091/02092, and mssql-jdbc and PostgreSQL report their deadlock as 40001 and 40P01 -
|
* so they are excluded from the blanket class 40 match rather than that match being narrowed to a whitelist,
|
* which would fail a further engine reporting a conflict of its own.
|
*/
|
private static final Set<String> NON_REPLAYABLE_ROLLBACK_STATES =
|
Collections.unmodifiableSet(new HashSet<>(Arrays.asList("40002", "40003")));
|
|
/** SQLState class 08, connection exception: the connection is gone, whatever the statement asked for. */
|
private static final String CONNECTION_FAILURE_CLASS = "08";
|
|
/**
|
* The states outside class 08 that also say the connection is gone rather than the statement wrong. PostgreSQL
|
* announces the connection it is about to drop as 57P01 (admin_shutdown - a pg_terminate_backend of an idle
|
* connection reaper, or a shutdown of the server), 57P02 (crash_shutdown) or 57P03 (cannot_connect_now), and
|
* only the next use of that connection is reported as class 08. They are the states of the list HikariCP
|
* evicts a connection on that a driver of this backend reports: of the rest, JZ0C0 and JZ0C1 belong to a Sybase
|
* driver this backend is not used with, 01002 is a disconnect none of these four drivers reports, and 0A000 is
|
* the standard "feature not supported", which says nothing about the connection at all.
|
*/
|
private static final Set<String> CONNECTION_FAILURE_STATES =
|
Collections.unmodifiableSet(new HashSet<>(Arrays.asList("57P01", "57P02", "57P03")));
|
|
private JDBCBackendCfg config;
|
|
public JDBCStorage(JDBCBackendCfg cfg, ServerContext serverContext) {
|
this.config = cfg;
|
cfg.addJDBCChangeListener(this);
|
}
|
|
//config
|
@Override
|
public boolean isConfigurationChangeAcceptable(JDBCBackendCfg configuration,List<LocalizableMessage> unacceptableReasons) {
|
return true;
|
}
|
|
@Override
|
public ConfigChangeResult applyConfigurationChange(JDBCBackendCfg cfg) {
|
final ConfigChangeResult ccr = new ConfigChangeResult();
|
try
|
{
|
this.config = cfg;
|
}
|
catch (Exception e)
|
{
|
addErrorMessage(ccr, LocalizableMessage.raw(stackTraceToSingleLineString(e)));
|
}
|
return ccr;
|
}
|
|
/**
|
* What a statement of this backend may legitimately take, and the property bounding it. One
|
* value cannot serve both: an entry read is a single row of an index, while the count of a
|
* tree and the delete that empties one before an import are a scan and a rewrite of a whole
|
* table, which take minutes on a populated backend and are not a symptom of anything.
|
*/
|
enum StatementBound {
|
/** one row by primary key, or one batch of a cursor along its index */
|
OPERATION("org.openidentityplatform.opendj.jdbc.query.timeout", 120),
|
/**
|
* a whole table at once: count(*), the delete of clearTree, the scan behind the highest
|
* entry id, create index, drop table, and every batch of a cursor walking a tree whole.
|
* This class ships <em>unbounded</em>: what such a statement legitimately takes follows the
|
* size of the backend and the speed of its database, neither of which can be guessed here,
|
* so the deployment that knows both sets the property - until it does, a create index
|
* waiting for a metadata lock still waits for as long as the engine lets it, and so do the
|
* walks a backend makes while it opens (the load of the compressed schema, the read that
|
* checks id2entry is there) and the export behind the generation ID of a replicated domain.
|
* That is what this backend did before any of these bounds existed; bounding them as the
|
* work of a client operation, which is the only other value there was to give them, stopped
|
* a large backend from opening at all.
|
*/
|
BULK("org.openidentityplatform.opendj.jdbc.bulk.timeout", 0);
|
|
final String property;
|
final int defaultSeconds;
|
|
StatementBound(String property, int defaultSeconds) {
|
this.property = property;
|
this.defaultSeconds = defaultSeconds;
|
}
|
|
/**
|
* The bound in seconds, as configured by {@link #property}: 0, or a negative value, leaves
|
* the statement unbounded, as it was before this bound existed, while a value that is not a
|
* number is ignored in favour of {@link #defaultSeconds} - {@code Integer.getInteger()}
|
* falls back to its default rather than reading such a value as a zero. A value above
|
* {@link JDBCStorage#MAX_BOUND_SECONDS} is taken down to it, for the reason recorded there.
|
*/
|
int seconds() {
|
return clampSeconds(Integer.getInteger(property, defaultSeconds));
|
}
|
}
|
|
/** What a caller of {@link #executeResultSet} makes of the rows, while the bound is still armed. */
|
interface RowsHandler<T> {
|
T handle(ResultSet rows) throws SQLException;
|
}
|
|
/**
|
* The value of a row that is there. A row whose {@code v} is null is one this backend never
|
* wrote - the column is nullable, however it is written - and it must not be answered with the
|
* {@code null} a single-row read uses, which is already taken and means "no such key": read that
|
* way, a key that exists is reported as absent. Named rather than left to the bare
|
* {@code NullPointerException} of {@code ByteString.wrap}, which names neither the fault nor the
|
* table it is in, and a {@code RuntimeException} rather than an {@code SQLException}, so that a
|
* corrupt row is never weighed against the bound of the statement that read it and reported as a
|
* timeout of a property that would have changed nothing. The key is left out of the message for
|
* the reason {@link #timedOut} leaves the statement out of its own: it is entry data.
|
*/
|
static ByteString valueOfRow(ResultSet rows, String tableName) throws SQLException {
|
return ByteString.wrap(valueOfRow(rows.getBytes("v"), tableName));
|
}
|
|
/**
|
* The same check where a batch of a cursor reads the value beside its key, by position. Checked
|
* as the rows are taken off the statement rather than as they are handed out one by one: there
|
* the failure is inside the bound and inside the {@code catch} of the batch, while a batch
|
* buffered whole and unwrapped later fails from {@code advanceFromBuffer()} - outside both, and
|
* as the bare {@code NullPointerException} this exists to replace.
|
*/
|
static byte[] valueOfRow(byte[] value, String tableName) {
|
if (value == null) {
|
throw new StorageRuntimeException("jdbc: a row of "+tableName+" is present with no value");
|
}
|
return value;
|
}
|
|
<T> T executeResultSet(PreparedStatement statement, RowsHandler<T> rows) throws SQLException {
|
return executeResultSet(statement, StatementBound.OPERATION, rows);
|
}
|
|
/**
|
* Runs a query under the bound of its class and hands the rows to {@code rows} while that bound
|
* is still armed. They are read there rather than after this method returns because a driver
|
* transfers them as they are asked for: read outside, the transfer - up to a whole batch of a
|
* cursor - would run with neither layer of the bound covering it, which is exactly where a
|
* database that stops answering mid-drain parks the worker thread. {@code setQueryTimeout}
|
* covering {@code ResultSet.next()} is optional in the JDBC contract ("drivers <em>may</em>
|
* also apply this limit"), and the two drivers of this backend that do not buffer a result
|
* whole - oracle prefetches ten rows at a time, mssql buffers adaptively - are the ones that
|
* do not.
|
*/
|
<T> T executeResultSet(PreparedStatement statement, StatementBound bound, RowsHandler<T> rows) throws SQLException {
|
if (logger.isTraceEnabled()) {
|
logger.trace(LocalizableMessage.raw("jdbc: %s",statement));
|
}
|
return bounded(statement, bound, () -> {
|
try (final ResultSet rs=statement.executeQuery()) {
|
return rows.handle(rs);
|
}
|
});
|
}
|
|
int execute(PreparedStatement statement) throws SQLException {
|
return execute(statement, StatementBound.OPERATION);
|
}
|
|
int execute(PreparedStatement statement, StatementBound bound) throws SQLException {
|
if (logger.isTraceEnabled()) {
|
logger.trace(LocalizableMessage.raw("jdbc: %s",statement));
|
}
|
return bounded(statement, bound, statement::executeUpdate);
|
}
|
|
interface Execution<T> {
|
T run() throws SQLException;
|
}
|
|
/**
|
* Runs a statement under the bound of its class. A statement of a class that carries one has to
|
* end: a row locked by an unrelated session, a table waiting for a metadata lock or a database
|
* that stops answering mid-query would otherwise park the worker thread that issued it for
|
* good. A class configured with no bound - which {@link StatementBound#BULK} ships as - takes
|
* neither of the two layers below and waits as this backend waited before they existed.
|
* <p>
|
* The bound is asked of the driver rather than of the session, because a pooled connection
|
* cannot carry a session setting - {@code CachedConnection.close()} only rolls back, so a
|
* {@code statement_timeout} of one operation would apply to whoever borrows the connection
|
* next - and it is applied in two layers, since the first one is not answered everywhere:
|
* {@code setQueryTimeout} cancels the statement and keeps the connection, while the socket read
|
* timeout behind it ends the wait even when the cancel is not acted upon. Oracle needs that
|
* second layer: a session blocked in a row-lock enqueue does not process the break its driver
|
* sends, so the timeout is armed and never arrives (the container suites cover it). That second
|
* layer belongs to the connection rather than to the statement, so it is arbitrated between the
|
* statements running on one - see {@link Backstop}.
|
*/
|
private <T> T bounded(PreparedStatement statement, StatementBound bound, Execution<T> execution) throws SQLException {
|
final int seconds=bound.seconds();
|
// whether the cancel is in force: a driver is free to refuse the query timeout, and then the
|
// socket read timeout behind it is the only layer this statement has - one that arrives later
|
final boolean cancelArmed=seconds > 0 && setQueryTimeout(statement, seconds);
|
// an unbounded class is announced to the connection all the same: a statement told it may
|
// take as long as it needs must not be cut by the socket read timeout of a concurrent one
|
return bounded(connectionOf(statement), bound.property, seconds, cancelArmed, execution);
|
}
|
|
/**
|
* Runs the catalog lookups of {@code openTree()} under the bound of their class. They ask
|
* {@code DatabaseMetaData}, which takes no query timeout, so the socket read timeout behind the
|
* cancel is the only layer they can be given - and they do need one: they run once per tree on
|
* every open of a backend, and the catalog is answered by the same engine, behind the same
|
* locks, as the {@code create table} they guard.
|
* <p>
|
* That layer is only as good as what it actually arms, which is not always something: a driver
|
* with no network timeout, a connection that failed the call, one already carrying a tighter
|
* timeout of a deployment's own, and a statement of an unbounded class running beside this one
|
* each leave such a lookup with no bound at all. It is then reported as what it is - see
|
* {@link #timedOut} - rather than as a property that bounded nothing.
|
*/
|
<T> T bounded(Connection con, StatementBound bound, Execution<T> execution) throws SQLException {
|
// no cancel to arm: DatabaseMetaData takes no query timeout, so the socket read timeout behind
|
// it is the only layer these have, and nothing ends their wait before the margin of that layer
|
return bounded(con, bound.property, bound.seconds(), false, execution);
|
}
|
|
/**
|
* Runs a statement under a bound of its own rather than under the bound of a class, for the one
|
* statement that has a property of its own: the statistics refresh after an import, which
|
* legitimately takes as long as a scan of the table it describes.
|
*/
|
private <T> T bounded(Connection con, String property, int seconds, boolean cancelArmed, Execution<T> execution)
|
throws SQLException {
|
final long startedAt=nanoTime();
|
final Backstop backstop=holdBackstop(con, seconds);
|
try {
|
return execution.run();
|
}catch (SQLException e) {
|
// what the second layer carries is read here rather than at the top: it is arbitrated
|
// between the statements in flight, so it is the value at the moment of the failure that
|
// bounded this statement - and it is read before the release below takes it back off
|
throw timedOut(e, property, seconds, cancelArmed, armedMillis(backstop), startedAt);
|
}finally {
|
releaseBackstop(backstop, con, seconds);
|
}
|
}
|
|
/**
|
* What the socket read timeout of a connection carries for the statements on it right now, or 0
|
* where this layer is not in force for them at all. It is not enough that a bound was asked for:
|
* {@link #applyBackstop} arms nothing on a connection whose driver refused the call or has no
|
* network timeout to give, nothing on one already carrying a timeout of a deployment's own that
|
* is tighter than ours, and nothing while a statement of an unbounded class runs beside this one.
|
*/
|
private static int armedMillis(Backstop state) {
|
if (state == null) {
|
return 0; // no connection to arm it on: the cancel is the whole bound of such a statement
|
}
|
synchronized (state) {
|
return state.armed;
|
}
|
}
|
|
/**
|
* Asks the driver to cancel the statement at the bound. Not every driver has one: the JDBC
|
* contract allows {@code SQLFeatureNotSupportedException} and this backend takes whatever URL a
|
* deployment configures, so a driver without it degrades to the socket read timeout behind it
|
* rather than failing every statement it is given.
|
*/
|
private boolean setQueryTimeout(PreparedStatement statement, int seconds) {
|
try {
|
statement.setQueryTimeout(seconds);
|
return true;
|
}catch (SQLException | RuntimeException e) {
|
if (queryTimeoutWarned.compareAndSet(false, true)) {
|
logger.warn(LocalizableMessage.raw("jdbc: the driver would not take a query timeout (%s): a statement of this"
|
+ " backend is left to the socket read timeout behind it", e.getMessage()));
|
}
|
return false;
|
}
|
}
|
|
private Connection connectionOf(PreparedStatement statement) {
|
try {
|
return statement.getConnection();
|
}catch (SQLException | RuntimeException e) {
|
return null; // nothing to arm the backstop on; the cancel above is the whole bound
|
}
|
}
|
|
/** How long the socket read timeout outlasts the cancel it backs up, giving it room to arrive. */
|
static final int BACKSTOP_MARGIN_SECONDS = 30;
|
|
/** How far under its bound a driver may report the cancel, its timer being kept in whole seconds. */
|
static final long CLOCK_SLACK_MILLIS = 250;
|
|
/**
|
* Ceiling of every bound this backend arms, in seconds - 24.9 days, which is what a socket read
|
* timeout can hold at all: {@code setNetworkTimeout} takes milliseconds of an {@code int}, and a
|
* bound past this one has no value of that layer to be given. It is <em>not</em> what keeps the
|
* arithmetic of {@link #backstopMillis} in range - the {@code long} multiply under the
|
* {@code Math.min} there does that on its own, up to the point where adding the margin overflows
|
* an {@code int} before the multiply ever runs - so a reader who later takes that {@code Math.min}
|
* away must not read this clamp as covering them.
|
* <p>
|
* Clamped rather than refused, and clamped rather than read as "no bound": a bound this large
|
* cancels nothing a database will not have ended first, so taking a nonsensical value down to it
|
* costs a deployment nothing, while reading it as an unbound would take a bound away from a
|
* deployment that asked for one. A property set to {@code Integer.MAX_VALUE} therefore bounds a
|
* statement at 24.9 days rather than leaving it unbounded; {@code 0} is what leaves it unbounded.
|
*/
|
static final int MAX_BOUND_SECONDS = Integer.MAX_VALUE/1000 - BACKSTOP_MARGIN_SECONDS;
|
|
static int clampSeconds(int seconds) {
|
return Math.max(0, Math.min(MAX_BOUND_SECONDS, seconds));
|
}
|
|
/**
|
* What {@link #timedOut} calls the second layer when that layer is the only one a statement ran
|
* under, so that a test can tell the two apart in a message: a run where the first layer stopped
|
* working degrades to this one by design, silently, and a suite that only measures how long a
|
* statement waited would go green with the cancel gone entirely.
|
*/
|
static final String BACKSTOP_ALONE = "the socket read timeout behind ";
|
|
// The clock a bound is measured on, in one place so that a test can drive it: the classification
|
// below turns on a few milliseconds either side of the bound, and a mock statement cannot be made
|
// to take a real second without the suite taking one too. Monotonic, so that a step of the wall
|
// clock can neither lengthen nor shorten what a statement is measured to have taken.
|
long nanoTime() {
|
return System.nanoTime();
|
}
|
|
// setNetworkTimeout() takes the executor its timeout handling runs on; the drivers of this
|
// backend only set a socket option in it, so it costs a call rather than a thread.
|
private static final Executor DIRECT_EXECUTOR = Runnable::run;
|
|
// Set when the driver of this storage has no network timeout to give at all, which is a property
|
// of the driver rather than of a connection: asking it again would cost a throw per statement,
|
// and the entry a connection's Backstop lives in is gone as soon as nothing runs on it. Held per
|
// storage rather than per JVM, like the warnings below: a driver that will not take one of these
|
// says so once for every backend running on it, instead of one backend silencing it for all.
|
private final AtomicBoolean backstopUnsupported = new AtomicBoolean();
|
private final AtomicBoolean backstopUnsupportedWarned = new AtomicBoolean();
|
private final AtomicBoolean backstopFailedWarned = new AtomicBoolean();
|
private final AtomicBoolean queryTimeoutWarned = new AtomicBoolean();
|
|
/**
|
* The socket read timeout of one connection, and the statements running on it. This second
|
* layer of the bound is a property of the socket rather than of a statement, so it cannot be
|
* armed and put back per statement wherever a connection carries more than one at a time: an
|
* {@code ImporterImpl} holds a single connection for the whole of an import and writes to it
|
* from every phase-one worker and every phase-two task, and there the first statement to finish
|
* would take the backstop away from every statement still in flight - while a statement whose
|
* class carries no bound at all would run under whatever value a concurrent one happened to
|
* arm, dying at it with nothing to say which property cut it, since such a statement never
|
* reaches {@link #timedOut}.
|
* <p>
|
* So the value armed is the loosest of the bounds of the statements in flight, and a statement
|
* with no bound of its own takes it off for as long as it runs: this backstop exists to end a
|
* wait nothing else would end, never to cut a statement that was told it may take as long as it
|
* needs. What the connection carried before is put back when the last of them is through.
|
*/
|
private static final class Backstop {
|
/** Bounds of the statements in flight, in milliseconds and by count, the loosest last. */
|
final TreeMap<Integer,Integer> bounds=new TreeMap<>();
|
/** Statements in flight with no bound of their own, which no backstop may cut short. */
|
int unbounded;
|
/** Statements holding this entry, bounded or not: at zero it leaves {@link #backstops}. */
|
int holders;
|
/** What the connection carried before the backstop armed it, and is given back afterwards. */
|
int previous;
|
/** What the backstop has armed, or 0 when the connection carries {@link #previous}. */
|
int armed;
|
/**
|
* Set when the driver would not take a network timeout on this connection: it is not asked
|
* again while the statements holding this entry run. A connection is the right scope for
|
* that: the common cause is a connection on its way out, and a driver that has no network
|
* timeout at all is remembered for the whole storage instead - see {@link #backstopUnsupported}.
|
*/
|
boolean failed;
|
}
|
|
// Keyed by identity on the connection of the driver: CachedConnection.prepareStatement() hands
|
// the statement to the connection it wraps, so that is the one a statement reports, while the
|
// catalog lookups above hold the wrapper of that same connection - both have to find the same
|
// entry, so a wrapper is unwrapped on the way in. Static because the pool these connections
|
// come from is static; an entry lives only while statements are running on its connection.
|
private static final Map<Connection,Backstop> backstops = new IdentityHashMap<>();
|
|
private static Connection physical(Connection con) {
|
return con instanceof CachedConnection ? ((CachedConnection)con).parent : con;
|
}
|
|
/**
|
* Puts the bound of a statement about to run on the connection that will run it, and makes the
|
* socket read timeout of that connection fit every statement in flight on it. Reaching this
|
* bound, unlike reaching the cancel it backs up, costs the connection: the driver closes it,
|
* which is the price of a wait the database was never going to end on its own.
|
*/
|
private Backstop holdBackstop(Connection con, int seconds) {
|
final Connection physical=physical(con);
|
if (physical == null) {
|
return null;
|
}
|
final Backstop state;
|
synchronized (backstops) {
|
state=backstops.computeIfAbsent(physical, c -> new Backstop());
|
state.holders++; // held from here, so that the entry outlives a concurrent release
|
}
|
synchronized (state) {
|
if (seconds > 0) {
|
state.bounds.merge(backstopMillis(seconds), 1, Integer::sum);
|
}else {
|
state.unbounded++;
|
}
|
applyBackstop(physical, state);
|
}
|
return state;
|
}
|
|
private void releaseBackstop(Backstop state, Connection con, int seconds) {
|
if (state == null) {
|
return;
|
}
|
final Connection physical=physical(con);
|
try {
|
synchronized (state) {
|
if (seconds > 0) {
|
final int millis=backstopMillis(seconds);
|
final Integer inFlight=state.bounds.get(millis);
|
if (inFlight == null || inFlight <= 1) {
|
state.bounds.remove(millis);
|
}else {
|
state.bounds.put(millis, inFlight-1);
|
}
|
}else {
|
state.unbounded--;
|
}
|
applyBackstop(physical, state);
|
}
|
}finally { // the entry is let go whatever the driver did, so that it cannot outlive its connection
|
synchronized (backstops) {
|
if (--state.holders <= 0) { // nothing is running on it: the connection is on its own again
|
backstops.remove(physical);
|
}
|
}
|
}
|
}
|
|
private static int backstopMillis(int seconds) {
|
return (int) Math.min(Integer.MAX_VALUE, (seconds+BACKSTOP_MARGIN_SECONDS)*1000L);
|
}
|
|
/**
|
* Makes the socket read timeout of the connection what the statements in flight on it need: the
|
* loosest of their bounds, or nothing of ours at all while one of them carries no bound. Called
|
* with the monitor of {@code state} held, since it both reads those counts and acts on the
|
* driver.
|
*/
|
private void applyBackstop(Connection con, Backstop state) {
|
if (state.failed || backstopUnsupported.get()) {
|
// but a connection this backstop has already armed does not keep carrying it: the entry
|
// remembering what it carried before is dropped when its last statement is through, and the
|
// value would go back to the pool as the connection's own read timeout. Reachable through
|
// the second guard, which is a latch of the whole storage: a connection armed before it was
|
// set would otherwise never be disarmed. Where nothing was armed this costs no call.
|
restorePrevious(con, state);
|
return;
|
}
|
final int wanted=state.unbounded > 0 || state.bounds.isEmpty() ? 0 : state.bounds.lastKey();
|
try {
|
if (wanted == 0) {
|
if (state.armed != 0) {
|
con.setNetworkTimeout(DIRECT_EXECUTOR, state.previous);
|
state.armed=0;
|
}
|
return;
|
}
|
if (state.armed == 0) {
|
state.previous=con.getNetworkTimeout();
|
}
|
// only ever tighten: a connection that already carries a read timeout carries one a
|
// deployment asked for, and this backstop exists to cap a cancel that is not acted
|
// upon, not to relax anything. 0 is "no timeout" in the JDBC contract, so it is the
|
// one value there is always something to gain by replacing.
|
if (state.previous > 0 && state.previous <= wanted) {
|
if (state.armed != 0) {
|
con.setNetworkTimeout(DIRECT_EXECUTOR, state.previous);
|
state.armed=0;
|
}
|
return;
|
}
|
if (state.armed != wanted) {
|
con.setNetworkTimeout(DIRECT_EXECUTOR, wanted);
|
state.armed=wanted;
|
}
|
}catch (SQLException | RuntimeException e) {
|
state.failed=true; // whatever the cause, this connection is not asked again while it runs
|
// and what it carried before goes back, while there is still an entry saying what that was:
|
// this one is dropped as soon as the last statement on the connection is through, and a
|
// backstop left armed would go back to the pool as the connection's own read timeout - which
|
// is exactly how the next borrower reads it, tightening to it and never replacing it.
|
restorePrevious(con, state);
|
// The two causes are told apart, because they deserve opposite treatment and one of them
|
// would otherwise spend the single warning the other needs: a driver with no network
|
// timeout at all says so through SQLFeatureNotSupportedException, and there is nothing to
|
// gain by asking it once per statement for the life of the storage, while a connection on
|
// its way out - it may be the one that reached this very timeout - says nothing about the
|
// driver and must not disable the backstop for the connections that are still healthy.
|
if (e instanceof SQLFeatureNotSupportedException) {
|
backstopUnsupported.set(true);
|
if (backstopUnsupportedWarned.compareAndSet(false, true)) {
|
logger.warn(LocalizableMessage.raw("jdbc: the driver takes no socket read timeout (%s): a statement the"
|
+ " database does not cancel will wait for it indefinitely, unless the connect properties of the URL"
|
+ " configured for this backend carry one", e.getMessage()));
|
}
|
}else if (backstopFailedWarned.compareAndSet(false, true)) {
|
logger.warn(LocalizableMessage.raw("jdbc: the socket read timeout backing up a cancelled statement could not"
|
+ " be set on a connection (%s): a statement the database does not cancel will wait for it"
|
+ " indefinitely there", e.getMessage()));
|
}
|
}
|
}
|
|
/**
|
* Gives the connection back the read timeout it carried before this backstop armed one, and
|
* forgets having armed it. Best effort by construction: the caller reaches this from a driver
|
* call that has just failed, so the connection may well be gone - and where it is, it is the
|
* driver that closes it rather than this backend.
|
*/
|
private static void restorePrevious(Connection con, Backstop state) {
|
if (state.armed == 0) {
|
return; // the connection carries its own value already
|
}
|
try {
|
con.setNetworkTimeout(DIRECT_EXECUTOR, state.previous);
|
}catch (SQLException | RuntimeException ignored) {
|
// nothing further can be done for this connection here, and the failure to report is the
|
// one that brought us into the catch above
|
}finally {
|
state.armed=0;
|
}
|
}
|
|
// Every driver reports a cancelled statement differently - postgresql as 57014, oracle as
|
// ORA-01013, and neither of them as a SQLTimeoutException - so the bound is recognized by the
|
// time the statement took rather than by the class or the state of its failure, and that time
|
// is taken from the monotonic clock, which a step of the wall clock can neither lengthen nor
|
// shorten. What it cannot tell apart is a failure of another kind arriving after the bound,
|
// which is why the failure it replaces is chained rather than swallowed. The SQL state and the
|
// error number are carried over as well, since a failure that arrives at the bound may still be
|
// one a caller classifies: a mysql lock wait, reported in class 40, ends inside a longer bound
|
// and stays the replayable conflict it is. The statement itself is left out of the message: a
|
// driver renders it with its parameters bound, and those are entry data.
|
private SQLException timedOut(SQLException e, String property, int seconds, boolean cancelArmed,
|
int backstopArmedMillis, long startedAt) {
|
if (seconds <= 0) {
|
return e;
|
}
|
// Which layer was really in force, and until when. Where the cancel is armed, the property
|
// ends the wait at its own value. Where it is not - a statement of DatabaseMetaData takes no
|
// query timeout, and a driver is free to refuse one - the socket read timeout behind it is the
|
// only layer there is, and that one arrives a margin later: measuring such a statement against
|
// the property alone reported a connection reset at 121 s as a query timeout of 120 s and sent
|
// the operator to a property that bounded nothing. Asking for that layer is not having it,
|
// which is why the value armed is passed in rather than derived from the property here: a
|
// driver with no network timeout, a connection that failed the call, one already carrying a
|
// tighter timeout of its own, and a statement of an unbounded class running beside this one
|
// each leave it unarmed. A statement neither layer bounded reached no bound of ours at all, so
|
// its failure is the driver's own and is left exactly as it is: naming a property that armed
|
// nothing sends an operator to raise a value that changes nothing about the wait they saw.
|
final long endsAfterMillis=cancelArmed ? seconds*1000L : backstopArmedMillis;
|
if (endsAfterMillis <= 0) {
|
return e;
|
}
|
final long elapsedMillis=(nanoTime()-startedAt)/1000000L;
|
// The bound is allowed a little slack under it: a driver keeps its timer in whole seconds and
|
// reports the cancel a few milliseconds before the bound is arithmetically due, and measured
|
// to the millisecond such a statement would arrive as a bare 57014 or ORA-01013, naming
|
// neither the property that cancelled it nor the fact that it was cancelled at all.
|
if (elapsedMillis < endsAfterMillis-CLOCK_SLACK_MILLIS) {
|
return e;
|
}
|
// The time is reported as measured rather than as the bound. Where the database does not act
|
// on the cancel - a session blocked in a row-lock enqueue on oracle - the wait ends at the
|
// socket read timeout, a margin past the property that armed it, and "did not finish within
|
// the 120s" of a statement that waited 150 s is a message an operator cannot put next to a
|
// clock. The property named still governs both layers, since backstopMillis() derives the
|
// second one from it, so raising it stays the remedy either way.
|
return new SQLTimeoutException("jdbc: the statement took "+elapsedMillis+" ms, reaching the "
|
+(endsAfterMillis/1000L)+"s of "
|
+(cancelArmed ? property : BACKSTOP_ALONE+property+" (the only layer bounding a statement that takes no"
|
+" query timeout; it is armed at the loosest bound of the statements sharing this connection, this"
|
+" one's being "+seconds+"s plus the margin of that layer)")
|
+": raise that property, or set it to 0 for no bound", e.getSQLState(), e.getErrorCode(), e);
|
}
|
|
// Unlike execute(), tolerates a statement that returns a result set - the comment statement of
|
// mssql is a batch that ends in an exec - and, unlike it, carries no bound of its own: what is
|
// left of this method runs on a stamp connection, which is given a lock timeout of its own
|
// (Dialect.lockTimeoutSql) and a socket read timeout in its connect properties.
|
void executeAny(PreparedStatement statement) throws SQLException {
|
if (logger.isTraceEnabled()) {
|
logger.trace(LocalizableMessage.raw("jdbc: %s",statement));
|
}
|
statement.execute();
|
}
|
|
Connection getConnection() throws Exception {
|
return getConnection(true);
|
}
|
|
/**
|
* The connection string this storage borrows on, distrusts and closes with: the one
|
* {@link #open(AccessMode)} registered with, and only failing that the one config names now. Every path
|
* that names a pool goes through here, for the reason given in {@link #getConnection(boolean)} - a
|
* db-directory changed on a running backend otherwise sends each of them to a different pool.
|
*/
|
private String poolKey() {
|
final String registered=poolConnectionString;
|
return registered!=null ? registered : config.getDBDirectory();
|
}
|
|
/**
|
* Borrows a connection the pool validates whatever the alive window of
|
* {@link CachedConnection#ALIVE_BYPASS_PROPERTY} says, for the borrows this class compensates a dropped
|
* connection on in no other way: {@link #open(AccessMode)}, {@link #removeStorageFiles()} and the importer
|
* issue their statements far from the borrow, and the open issues none at all, so a connection dropped inside
|
* the window would surface out of the rollback that releases it. One round trip on a path taken once per open,
|
* per import or per removal buys back exactly what master did on every borrow.
|
*/
|
Connection getValidatedConnection() throws Exception {
|
return getConnection(false);
|
}
|
|
// The one borrow of this storage: both methods above go through it, so that whatever stands in
|
// for the pool stands in for every path that takes a connection. A stand-in of the trusted
|
// borrow alone let the open, the import and the removal - the three that ask for a validated
|
// one - reach a real database instead.
|
//
|
// It names the pool this storage registered with in open(), not the one config names now.
|
// Nothing keeps db-directory from being changed on a running backend - applyConfigurationChange()
|
// takes it, isConfigurationChangeAcceptable() refuses nothing, and the component-restart admin
|
// action renders a message rather than holding the change back - so re-reading it here would
|
// borrow from a pool this storage never registered with, leaving the one it did register with
|
// holding a user that never borrows: the leak of #878 back through the configuration. And an
|
// unregistered pool is drained the moment another backend that did register with it closes,
|
// with this one still borrowing from it (issue #878).
|
Connection getConnection(boolean trusted) throws Exception {
|
return CachedConnection.getConnection(poolKey(), trusted);
|
}
|
|
|
AccessMode accessMode=AccessMode.READ_ONLY;
|
|
// Whether this storage counts as a user of the pool of its connection string. The pool belongs
|
// to the database rather than to this backend - two backends may address one database - so it
|
// is reference counted, and this flag keeps an open() or a close() that comes twice from
|
// counting twice (issue #878).
|
private final AtomicBoolean poolRegistered=new AtomicBoolean();
|
|
// The connection string open() registered with. applyConfigurationChange() replaces config, so
|
// reading db-directory again at close() could give back the pool of a database this storage
|
// never registered with - leaving the one it did with a user it never loses (issue #878).
|
private volatile String poolConnectionString;
|
|
@Override
|
public void open(AccessMode accessMode) throws Exception {
|
final boolean claimedHere=poolRegistered.compareAndSet(false, true);
|
// Raised once openPool() has returned, which is when a user has actually been added. The
|
// claim alone cannot answer for that: releasePool() on a claim openPool() never made would
|
// take a user off a pool this storage never added one to - and the pool of a database two
|
// backends share would lose the user of the other one, draining connections it is still
|
// borrowing.
|
boolean registeredHere=false;
|
try {
|
// Inside the try, so that the registration this call made is given back however the open
|
// ends - the registration is taken before the pool is of any use, and a pool holding a
|
// user that never borrows keeps its connections for a borrower that is not going to come.
|
if (claimedHere) {
|
poolConnectionString=config.getDBDirectory();
|
CachedConnection.openPool(poolConnectionString);
|
registeredHere=true;
|
}
|
// The validated borrow is the whole of the open, and nothing is taken from it here: the
|
// status is set below rather than inside the block, or a throw from the implicit close()
|
// - the rollback of the return goes to the database - would leave the storage reporting
|
// working() while this method fails and the catch takes its registration back. write()
|
// and ImporterImpl both skip the re-open when the status says working, so the pool would
|
// be left with no user at all: every connection returned to it destroyed on the spot,
|
// pooling off for that database for as long as the server runs (issue #878).
|
try (final Connection con=getValidatedConnection()) {
|
}
|
} catch (Throwable e) {
|
// Throwable rather than Exception: an Error out of the borrow - a NoClassDefFoundError
|
// from the static initializer of a driver is the one to expect here - would otherwise
|
// leave the pool holding a user that never leaves.
|
// Only what this call registered is given back: an open that found the registration
|
// already made took nothing, and giving it back would release a pool still in use.
|
if (registeredHere) {
|
releasePool();
|
} else if (claimedHere) {
|
// The claim was won but no user was added. The claim goes back on its own, without
|
// touching the pool: left standing it would send the close() of this storage to
|
// releasePool() for a registration it never made.
|
poolConnectionString=null;
|
poolRegistered.set(false);
|
}
|
throw e;
|
}
|
this.accessMode = accessMode;
|
storageStatus = StorageStatus.working();
|
}
|
|
/** Gives up the registration of this storage with the pool of the database it opened. */
|
private void releasePool() {
|
if (poolRegistered.compareAndSet(true, false)) {
|
final String registered=poolConnectionString;
|
poolConnectionString=null;
|
if (registered!=null) {
|
CachedConnection.closePool(registered);
|
}
|
}
|
}
|
|
private StorageStatus storageStatus = StorageStatus.lockedDown(LocalizableMessage.raw("closed"));
|
@Override
|
public StorageStatus getStorageStatus() {
|
return storageStatus;
|
}
|
|
@Override
|
public void close() {
|
storageStatus = StorageStatus.lockedDown(LocalizableMessage.raw("closed"));
|
// a stamp that the database rejected is remembered for as long as the storage is open, so
|
// that it is not reissued for every tree on every open; disabling and re-enabling the
|
// backend is the way to try again once the privilege has been granted
|
unstampableTrees.clear();
|
// A closed backend has no use for its connections. They used to stay open - close() only
|
// flipped the status - so disabling or removing a JDBC backend left them behind, and with
|
// nothing left to expire the pool entry they could stay open for good (issue #878).
|
releasePool();
|
}
|
|
// The trees this storage has taken an interest in, and the tables they map to. listTrees() -
|
// and through it removeStorageFiles() - reads this, so a tree only belongs here once this
|
// backend uses it: see toTableName() below for the trees that are merely asked about.
|
final LoadingCache<TreeName,String> tree2table = Caffeine.newBuilder()
|
.build(JDBCStorage::toTableName);
|
|
/**
|
* The table a tree name maps to. A pure function of the name, so that a tree can be read
|
* without being entered into tree2table: the compressed schema reads the tree its definitions
|
* used to be shared under (#873), a tree this backend does not own, and removeStorageFiles()
|
* drops every table tree2table names.
|
* <p>
|
* Which of the two a statement takes therefore says who owns the tree it names: a path that
|
* creates or writes one - openTree(), clearTree(), deleteTree(), put(), update(), delete() -
|
* takes the enrolling {@link #getTableName(TreeName)}, and a read-only path - read(),
|
* getRecordCount(), isExistsTable() and the cursor - takes {@link #readTableName(TreeName)},
|
* which computes this only for a tree that is not enrolled already. Every tree this backend
|
* owns passes through openTree(name, true) as it is opened, so listTrees() still names the
|
* complete owned set.
|
*/
|
static String toTableName(TreeName treeName) {
|
try {
|
final MessageDigest md = MessageDigest.getInstance("SHA-224");
|
final byte[] messageDigest = md.digest(treeName.toString().getBytes());
|
final StringBuilder hashtext = new StringBuilder(56);
|
for (byte b : messageDigest) {
|
String hex = Integer.toHexString(0xff & b);
|
if (hex.length() == 1) hashtext.append('0');
|
hashtext.append(hex);
|
}
|
return "opendj_" + hashtext;
|
} catch (NoSuchAlgorithmException e) {
|
throw new RuntimeException(e);
|
}
|
}
|
|
String getTableName(TreeName treeName) {
|
return tree2table.get(treeName);
|
}
|
|
/**
|
* The table a tree name maps to, for a statement that only reads it. Answered from the memo of
|
* {@link #getTableName(TreeName)} where the tree is in it, and computed without being put there
|
* otherwise.
|
* <p>
|
* Every tree this backend owns is enrolled as it is opened, so the per-entry read path stays a
|
* map lookup: {@link #toTableName(TreeName)} takes a JCA provider lookup and a digest per call,
|
* which read() would otherwise pay for every entry of every search. Only a tree this backend
|
* does not own - the shared compressed schema tree the migration of #873 reads - is computed,
|
* twice per open of the backend.
|
*/
|
String readTableName(TreeName treeName) {
|
final String enrolled=tree2table.getIfPresent(treeName);
|
return enrolled!=null ? enrolled : toTableName(treeName);
|
}
|
|
/**
|
* The form a catalog pattern has to take to match an identifier this backend created unquoted.
|
* An unquoted identifier is folded when it is stored - to upper case on oracle, to lower case
|
* on postgresql - and a metadata pattern is matched against the stored form, not against the
|
* name as it was written. The driver is asked which way it folds, rather than its class name
|
* being matched, since this is what the JDBC contract exposes these two methods for.
|
*/
|
static String storedIdentifier(DatabaseMetaData metaData, String name) throws SQLException {
|
if (metaData.storesUpperCaseIdentifiers()) {
|
return name.toUpperCase();
|
}
|
if (metaData.storesLowerCaseIdentifiers()) {
|
return name.toLowerCase();
|
}
|
return name;
|
}
|
|
private static final String[] NO_ARGS=new String[0];
|
|
// Comment statements take a lock (a metadata lock on mysql, a schema modification lock on sql
|
// server, a ddl lock on oracle), and mysql and sql server wait for it without limit by
|
// default (lock_wait_timeout is a year, lock_timeout is infinite): a stamp could queue behind
|
// an unrelated transaction of another session on the same database and - on mysql - park
|
// every other query on the table behind itself. The stamp is a diagnostic aid, so every
|
// dialect is told to give up after this many seconds instead of waiting.
|
private static final int COMMENT_LOCK_TIMEOUT_SECONDS=5;
|
|
// The comment statement runs on a connection of its own (newStampConnection() below), and a
|
// driver waits for a connect attempt without limit unless it is told otherwise: a database
|
// that keeps its established connections alive but accepts no new ones (a moved vip, a proxy
|
// at its connection limit) would otherwise hang the open of a tree - dsconfig
|
// create-backend-index opens one on a running server - instead of leaving a table unstamped.
|
// Every dialect gets the same bound, in the unit its own driver property takes.
|
private static final int STAMP_CONNECT_TIMEOUT_SECONDS=10;
|
|
// Not one of the four drivers bounds the whole login attempt with its connect property alone:
|
// postgres and mysql apply theirs to socket.connect(), oracle's own reference says
|
// CONNECT_TIMEOUT "doesn't include user authentication", and the sql server driver leaves the
|
// read of the prelogin answer unbounded - TDSChannel.open() gives the socket
|
// min(what is left of loginTimeout, socketTimeout) and socketTimeout defaults to 0, which is
|
// "wait forever". Those reads - of the prelogin handshake, of tls, of authentication - are
|
// exactly where a proxy that accepts a connection and then goes quiet leaves the driver, so
|
// every dialect carries a read bound as well. All four are socket read timeouts, so the bound
|
// outlives the login phase and covers the comment statement too, which is why it is kept well
|
// clear of the lock bound above: the statement gives up on a contended lock long before the
|
// socket gives up on the server. On a mysql connection with tls (the sslMode=PREFERRED default
|
// of connector/j) the wall clock of a dead peer is twice this, since closing an SSLSocket
|
// drains input waiting for close_notify and pays the read bound a second time.
|
private static final int STAMP_READ_TIMEOUT_SECONDS=30;
|
|
// Trees whose stamp failed for a reason that is not going to change by itself: an account that
|
// may not comment its tables (no ALTER privilege, for instance) would otherwise reissue the
|
// statement for every tree on every open. A failure that says nothing about the table - a lock
|
// timeout, a connection that broke - is not remembered (failureScope() below), so a contended
|
// moment does not leave the backend unstamped until it is restarted. Forgotten when the
|
// storage is closed, so re-enabling the backend is enough to try again once the privilege has
|
// been granted, without a restart of the server.
|
private final Set<TreeName> unstampableTrees=ConcurrentHashMap.newKeySet();
|
|
/**
|
* The engines whose comment statement, comment readback and statistics refresh this backend
|
* knows, with the session settings a comment statement needs: the driver properties that
|
* bound the connect attempt of the connection it runs on, and the statement that bounds its
|
* wait for the table lock.
|
*/
|
enum Dialect {
|
/** postgresql: lock_timeout takes milliseconds; connectTimeout bounds socket.connect(), loginTimeout the whole login the driver runs on a thread of its own, socketTimeout every read after it - all three in seconds. */
|
POSTGRES("set lock_timeout = "+(COMMENT_LOCK_TIMEOUT_SECONDS*1000),
|
"connectTimeout", STAMP_CONNECT_TIMEOUT_SECONDS, "loginTimeout", STAMP_CONNECT_TIMEOUT_SECONDS,
|
"socketTimeout", STAMP_READ_TIMEOUT_SECONDS),
|
/** mysql: lock_wait_timeout takes seconds; connectTimeout bounds the socket connect and socketTimeout every read after it, both in milliseconds. */
|
MYSQL("set session lock_wait_timeout="+COMMENT_LOCK_TIMEOUT_SECONDS,
|
"connectTimeout", STAMP_CONNECT_TIMEOUT_SECONDS*1000, "socketTimeout", STAMP_READ_TIMEOUT_SECONDS*1000),
|
/** oracle: ddl_lock_timeout takes seconds and defaults to 0 (give up at once), but it can be raised globally; the connect and read bounds take milliseconds. */
|
ORACLE("alter session set ddl_lock_timeout="+COMMENT_LOCK_TIMEOUT_SECONDS,
|
"oracle.net.CONNECT_TIMEOUT", STAMP_CONNECT_TIMEOUT_SECONDS*1000, "oracle.jdbc.ReadTimeout", STAMP_READ_TIMEOUT_SECONDS*1000),
|
/** ms sql server: lock_timeout takes milliseconds; loginTimeout bounds the socket connect, in seconds, and socketTimeout the prelogin read it leaves open - and every read after it - in milliseconds. */
|
MICROSOFT("set lock_timeout "+(COMMENT_LOCK_TIMEOUT_SECONDS*1000),
|
"loginTimeout", STAMP_CONNECT_TIMEOUT_SECONDS, "socketTimeout", STAMP_READ_TIMEOUT_SECONDS*1000);
|
|
final String lockTimeoutSql;
|
// The driver properties bounding the login attempt of a stamp connection: the one bounding
|
// the socket connect and the one bounding the reads behind it, each in the unit its own
|
// driver takes. newStampConnection() hands the driver a copy of them: a driver is free to
|
// write into the map it is passed, and the sql server one gives a supplied property
|
// precedence over the same property of the url.
|
final Properties connectProperties=new Properties();
|
|
/** For the three drivers whose connect property and read property bound the login between them. */
|
Dialect(String lockTimeoutSql, String connectProperty, int connectValue, String readProperty, int readValue) {
|
this.lockTimeoutSql=lockTimeoutSql;
|
connectProperties.setProperty(connectProperty, String.valueOf(connectValue));
|
connectProperties.setProperty(readProperty, String.valueOf(readValue));
|
}
|
|
/** For the one driver bounding the login itself, on top of the socket connect and the reads behind it. */
|
Dialect(String lockTimeoutSql, String connectProperty, int connectValue, String loginProperty, int loginValue,
|
String readProperty, int readValue) {
|
this(lockTimeoutSql, connectProperty, connectValue, readProperty, readValue);
|
connectProperties.setProperty(loginProperty, String.valueOf(loginValue));
|
}
|
}
|
|
/** Returns the class name of the driver behind the given connection, which names the engine it talks to. */
|
static String driverNameOf(Connection con) {
|
// a stamp connection comes straight from the driver, a transaction one from the pool
|
return ((con instanceof CachedConnection) ? ((CachedConnection) con).parent : con).getClass().getName();
|
}
|
|
// The dialect behind a pooled connection, or null for an engine none of the statements of this
|
// class fit: it is left unstamped and its statistics untouched rather than fed untested SQL.
|
static Dialect dialectOf(Connection con) {
|
final String driverName=driverNameOf(con);
|
if (driverName.contains("postgres")) {
|
return Dialect.POSTGRES;
|
}else if (driverName.contains("mysql")) {
|
return Dialect.MYSQL;
|
}else if (driverName.contains("oracle")) {
|
return Dialect.ORACLE;
|
}else if (driverName.contains("microsoft")) {
|
return Dialect.MICROSOFT;
|
}
|
return null;
|
}
|
|
/** Outcome of a comment stamp: openTree() ignores it, tests tell the cases apart. */
|
enum CommentResult {
|
/** the table now carries its tree name */
|
STAMPED,
|
/** the stored comment already matched: no statement was issued */
|
UP_TO_DATE,
|
/** neither comment syntax nor readback is known for this engine */
|
UNSUPPORTED,
|
/** the comment could not be read back or stored */
|
FAILED
|
}
|
|
// Splices a value into a single-quoted SQL literal for the comment DDL, which takes no bind
|
// parameters: doubles every quote, and every backslash on dialects where backslash is an
|
// escape character inside literals. The scan of the escaped result is defence in depth: it
|
// re-verifies that no quote (or live backslash) is left unpaired and able to terminate the
|
// literal, so a regression in the escaping throws instead of reaching the database.
|
private static String sqlLiteral(String value, boolean backslashIsEscape) {
|
final String escaped=(backslashIsEscape?value.replace("\\","\\\\"):value).replace("'","''");
|
for (int i=0;i<escaped.length();i++) {
|
final char c=escaped.charAt(i);
|
if (c=='\'' || (backslashIsEscape && c=='\\')) {
|
if (i+1>=escaped.length() || escaped.charAt(i+1)!=c) {
|
throw new IllegalArgumentException("unpaired "+c+" in SQL literal: "+escaped);
|
}
|
i++;
|
}
|
}
|
return "'"+escaped+"'";
|
}
|
|
// Whether backslash is an escape character inside string literals on this mysql connection:
|
// under the NO_BACKSLASH_ESCAPES sql mode it is an ordinary character, and doubling it there
|
// would store a comment that never matches its tree name - re-stamping the table forever.
|
// Asked of the very session that parses the literal: sql_mode is a session setting, and a
|
// session opened at another moment can have been given another value of it.
|
boolean isMysqlBackslashEscape(Connection con) throws SQLException {
|
try (final PreparedStatement statement=con.prepareStatement("select @@sql_mode")) {
|
final String sqlMode=executeResultSet(statement, rs -> rs.next() ? rs.getString(1) : null);
|
return sqlMode==null || !sqlMode.toUpperCase().contains("NO_BACKSLASH_ESCAPES");
|
}
|
}
|
|
// A connection of its own for the comment statements, outside the pool: they need session
|
// settings (the lock timeout above) that a pooled connection would carry over to whoever
|
// borrows it next, since CachedConnection.close() only rolls back.
|
Connection newStampConnection(Dialect dialect) throws SQLException {
|
final Properties properties=new Properties();
|
properties.putAll(dialect.connectProperties);
|
// poolKey() rather than the configuration as it stands: this connection is not pooled, but it
|
// is a connection to the database of this storage, and db-directory may be changed on a
|
// running backend. Reading it again here would stamp the trees of this backend in whichever
|
// database the configuration names now, while every other connection of it stays with the
|
// one open() registered (issue #878).
|
final Connection con=DriverManager.getConnection(poolKey(), properties);
|
try {
|
con.setAutoCommit(false);
|
executeSessionStatement(con, dialect.lockTimeoutSql); // give up instead of waiting for another session
|
// postgres undoes a plain SET when the transaction that ran it is rolled back, and a
|
// failed stamp is rolled back with the connection kept (StampSession.reset() below):
|
// commit the setting, or the first failure of a sweep would leave every tree after it
|
// stamped without the very bound this connection exists to carry. The session settings
|
// of the other three dialects are not transactional - the commit costs them an empty
|
// transaction.
|
con.commit();
|
}catch (SQLException e) { // nothing else holds this connection yet: it would leak
|
try {
|
con.close();
|
}catch (SQLException e2) {}
|
throw e;
|
}
|
return con;
|
}
|
|
// The connection the comment statements of one sweep of openTree() calls share. Opening a
|
// backend opens every tree it holds (about 25 for a stock suffix), so a connection per stamp
|
// would mean that many physical connects on the first open after an upgrade - the one open
|
// that stamps them all. Opened lazily: a sweep that finds every comment up to date, which is
|
// every open after the first, opens nothing at all.
|
final class StampSession implements Closeable {
|
private Connection con;
|
|
// Whether backslash escapes inside a literal on the connection above (mysql @@sql_mode).
|
// It is a session setting of a connection the whole sweep shares, so the sweep asks once
|
// instead of once per tree, and forgets it together with the session it describes.
|
private Boolean mysqlBackslashEscape;
|
|
// Set when a stamp failed for a reason no other tree of this sweep would escape either: a
|
// connect that did not go through, a lock the statement gave up on. Each remaining tree
|
// would pay that same bound - or that same connect attempt - again, which is a backend
|
// open held for the bound times the number of its trees, all for a diagnostic aid. The
|
// sweep gives up instead; nothing about the trees is remembered, so the next open retries.
|
private boolean gaveUp;
|
|
Connection connection(Dialect dialect) throws SQLException {
|
if (con==null) {
|
con=newStampConnection(dialect);
|
}
|
return con;
|
}
|
|
// Asked by the mysql statement only, and only once the connection above is open.
|
boolean backslashIsEscape() throws SQLException {
|
if (mysqlBackslashEscape==null) {
|
mysqlBackslashEscape=isMysqlBackslashEscape(con);
|
}
|
return mysqlBackslashEscape;
|
}
|
|
void giveUp() {
|
gaveUp=true;
|
}
|
|
boolean hasGivenUp() {
|
return gaveUp;
|
}
|
|
// A statement that failed can leave the session unusable (postgres refuses every further
|
// statement of the transaction with 25P02 until it is rolled back), so the stamp of the
|
// next tree gets a clean one: rolled back, or replaced when even the rollback fails.
|
void reset() {
|
if (con!=null) {
|
try {
|
con.rollback();
|
}catch (SQLException e) {
|
close();
|
}
|
}
|
}
|
|
@Override
|
public void close() {
|
if (con!=null) {
|
try {
|
con.close();
|
}catch (SQLException e) {
|
logger.trace(LocalizableMessage.raw("jdbc: unable to close the comment connection: %s", stackTraceToSingleLineString(e)));
|
}
|
con=null;
|
}
|
mysqlBackslashEscape=null; // it described the session that has just gone
|
}
|
}
|
|
// A session setting must reach the server as a plain batch: the sql server driver runs a
|
// prepared statement through sp_executesql, and a setting made there is reverted when that
|
// call returns - before the statement it is meant to protect ever runs.
|
//
|
// Outside both layers of the bound, like the comment statement executeAny() runs, and for the
|
// same reason: this is issued from newStampConnection() on a stamp connection, whose connect
|
// properties carry a socket read timeout of their own (Dialect.connectProperties).
|
private void executeSessionStatement(Connection con, String sql) throws SQLException {
|
try (final Statement statement=con.createStatement()) {
|
if (logger.isTraceEnabled()) {
|
logger.trace(LocalizableMessage.raw("jdbc: %s",sql));
|
}
|
statement.execute(sql);
|
}
|
}
|
|
// Table names are opaque SHA-224 hashes, so on the database side there is no way to tell
|
// which tree a table holds. Stamp each table with its tree name (visible in "\dt+" and the
|
// information schema) so database-level troubleshooting does not require recomputing hashes.
|
// Runs on a dedicated connection, never on the transaction that opened the tree: comment
|
// statements are DDL (an implicit commit on mysql and oracle), and a failing
|
// sp_addextendedproperty rolls the whole transaction back on sql server - either would
|
// corrupt work pending on the caller's connection (e.g. the trusted flag written by
|
// DefaultIndex.afterOpen()). The comment is a diagnostic aid: a failed attempt only logs and
|
// must not fail the backend.
|
CommentResult commentTable(TreeName treeName, Dialect dialect) {
|
try (final StampSession session=new StampSession()) { // a stamp of its own: no sweep to share a connection with
|
return commentTable(treeName, dialect, session);
|
}
|
}
|
|
CommentResult commentTable(TreeName treeName, Dialect dialect, StampSession session) {
|
final String tableName=getTableName(treeName);
|
if (dialect==null) { // no comment syntax and readback known for other engines: leave the table unstamped
|
return CommentResult.UNSUPPORTED;
|
}
|
if (unstampableTrees.contains(treeName)) { // the database already rejected this one: do not ask again
|
return CommentResult.FAILED;
|
}
|
if (session.hasGivenUp()) { // an earlier tree of this sweep lost the session every tree of it needs
|
logger.debug(LocalizableMessage.raw("jdbc: table %s is left unstamped: the stamp of an earlier table of this open lost its connection", tableName));
|
return CommentResult.FAILED;
|
}
|
final String treeComment=treeName.toString();
|
try {
|
// The readback runs on the stamp connection, not on one borrowed from the pool: the
|
// caller of openTree() is inside a transaction and holding a pooled connection already,
|
// and a pool that cannot open a second one waits for a peer to return one - which here
|
// is the very thread that is waiting. The dialect comes from the caller's connection
|
// for the same reason: finding it out must not cost a borrow either.
|
final Connection con=session.connection(dialect);
|
// comment statements are DDL (metadata lock on mysql, ddl lock on oracle) and openTree()
|
// runs on every backend open: only stamp when the stored comment is absent or stale
|
final String storedComment=readStoredComment(con, dialect, tableName);
|
// end the read: this connection is shared by every tree of the sweep and must not hold
|
// a transaction open across all of them
|
con.commit();
|
if (treeComment.equals(storedComment)) {
|
return CommentResult.UP_TO_DATE;
|
}
|
final String sql;
|
final String[] args;
|
switch (dialect) {
|
case MYSQL: // ALTER TABLE takes no binds; whether backslash escapes inside the literal depends on the sql mode of this session
|
sql="alter table "+tableName+" comment "+sqlLiteral(treeComment,session.backslashIsEscape());
|
args=NO_ARGS;
|
break;
|
case MICROSOFT: // no COMMENT ON in t-sql: MS_Description extended property (procedure arguments take binds)
|
sql="declare @s sysname = schema_name()"
|
+" if exists (select 1 from sys.extended_properties where class=1 and major_id=object_id(?) and minor_id=0 and name='MS_Description')"
|
+" exec sys.sp_updateextendedproperty N'MS_Description', ?, N'SCHEMA', @s, N'TABLE', ?"
|
+" else"
|
+" exec sys.sp_addextendedproperty N'MS_Description', ?, N'SCHEMA', @s, N'TABLE', ?";
|
args=new String[]{tableName, treeComment, tableName, treeComment, tableName};
|
break;
|
case POSTGRES: // no binds in ddl; the E'' form keeps backslash an escape character regardless of standard_conforming_strings
|
sql="comment on table "+tableName+" is E"+sqlLiteral(treeComment,true);
|
args=NO_ARGS;
|
break;
|
case ORACLE: // no binds in ddl; backslash is never an escape character in oracle literals
|
sql="comment on table "+tableName+" is "+sqlLiteral(treeComment,false);
|
args=NO_ARGS;
|
break;
|
default: // a dialect this switch was never told about must not inherit another one's ddl
|
throw new IllegalStateException("no comment statement for dialect "+dialect);
|
}
|
try (final PreparedStatement statement=con.prepareStatement(sql)) {
|
for (int i=0;i<args.length;i++) {
|
statement.setString(i+1,args[i]);
|
}
|
executeAny(statement);
|
con.commit();
|
}
|
return CommentResult.STAMPED;
|
}catch (Exception e) {
|
session.reset(); // what the failed statement left behind must not poison the stamp of the next tree
|
final FailureScope scope=failureScope(e, dialect);
|
if (scope==FailureScope.SESSION) {
|
// the connection itself is gone, and every tree left in this sweep needs one: each
|
// would pay the same connect attempt again, ~25 of them for a stock suffix
|
session.giveUp();
|
}else if (scope==FailureScope.TREE) {
|
unstampableTrees.add(treeName);
|
}
|
logger.warn(LocalizableMessage.raw("jdbc: unable to comment table %s with tree name %s, it stays unstamped %s (the comment is a diagnostic aid: the backend is unaffected): %s",
|
tableName, treeName, scope==FailureScope.TREE?"until this backend is closed":"for now", stackTraceToSingleLineString(e)));
|
return CommentResult.FAILED;
|
}
|
}
|
|
/** What a failed stamp says about stamping again - this tree, and the trees behind it in the same sweep. */
|
enum FailureScope {
|
/**
|
* The database rejected the statement: an account that may not comment its tables, say. It
|
* would be rejected again for this tree on every open, so the tree is remembered and not
|
* asked again while this backend is open. Says nothing about the other trees of the sweep,
|
* which are stamped as usual - the privilege may well be missing for this one table alone.
|
*/
|
TREE,
|
/**
|
* Another session held the table locked and the stamp gave up on the bound above. Nothing
|
* is remembered - the next open tries again - and the sweep goes on: the lock belongs to
|
* this table, and the trees behind it are no more likely to be contended than usual.
|
*/
|
MOMENT,
|
/**
|
* The connection the sweep runs on is gone, or was never established. Every tree left in
|
* the sweep would run into the same thing, one connect attempt each, so the sweep ends;
|
* nothing is remembered, since this says nothing about any of the tables.
|
*/
|
SESSION
|
}
|
|
// What a failed stamp says about trying again. Every chain of the failure is walked, by the walk
|
// every other classifier of this class uses: a driver reports the vendor error of a rejected
|
// statement as the next exception of a generic one at least as often as it reports it as the
|
// cause, the statement of a try-with-resources carries what its close() saw as a suppressed
|
// exception, and reading fewer of them than the others do would classify a connection that broke
|
// as a rejection - which leaves the tree unstamped for the life of the backend. Walked to its end
|
// rather than to MAX_CHAIN_LINKS: the seen set already terminates it, and the verdict weakens
|
// under truncation rather than simply going unnoticed - a SESSION past the budget would come back
|
// as TREE. The strongest verdict wins, so it is asked for in that order.
|
static FailureScope failureScope(Throwable failure, Dialect dialect) {
|
if (firstLinkMatching(failure, WITH_THE_RELEASE, EVERY_LINK,
|
e -> scopeOf(e, dialect)==FailureScope.SESSION)!=null) {
|
return FailureScope.SESSION;
|
}
|
if (firstLinkMatching(failure, WITH_THE_RELEASE, EVERY_LINK,
|
e -> scopeOf(e, dialect)==FailureScope.MOMENT)!=null) {
|
return FailureScope.MOMENT;
|
}
|
return FailureScope.TREE;
|
}
|
|
// What one exception of the chain says on its own.
|
private static FailureScope scopeOf(SQLException e, Dialect dialect) {
|
final String sqlState=e.getSQLState();
|
if (e instanceof SQLTransientConnectionException || e instanceof SQLNonTransientConnectionException
|
|| e instanceof SQLRecoverableException // what oracle throws for a connection that has gone
|
|| (sqlState!=null && sqlState.startsWith("08"))) { // connection exception
|
return FailureScope.SESSION;
|
}
|
if (e instanceof SQLTimeoutException || e instanceof SQLTransientException) {
|
return FailureScope.MOMENT;
|
}
|
if (dialect==null) { // the failure came before the engine was known
|
return FailureScope.TREE;
|
}
|
switch (dialect) {
|
case POSTGRES: // 55P03 lock not available: lock_timeout expired
|
return "55P03".equals(sqlState) ? FailureScope.MOMENT : FailureScope.TREE;
|
case MYSQL: // 1205 lock wait timeout exceeded
|
return e.getErrorCode()==1205 ? FailureScope.MOMENT : FailureScope.TREE;
|
case ORACLE: // ORA-00054 resource busy, ORA-04021 timeout occurred while waiting to lock object
|
return e.getErrorCode()==54 || e.getErrorCode()==4021 ? FailureScope.MOMENT : FailureScope.TREE;
|
case MICROSOFT: // 1222 lock request time out period exceeded
|
return e.getErrorCode()==1222 ? FailureScope.MOMENT : FailureScope.TREE;
|
default: // a dialect with no lock timeout code of its own here: its failures are not treated as ones of the moment
|
return FailureScope.TREE;
|
}
|
}
|
|
// Returns the comment currently stored on the table, or null when there is none. The dialect is
|
// passed in rather than read off the connection: this runs on the stamp connection, which is
|
// not a pooled one, and only for the dialects commentTable() recognizes.
|
String readStoredComment(Connection con, Dialect dialect, String tableName) throws SQLException {
|
final String sql;
|
final String arg;
|
switch (dialect) {
|
case POSTGRES:
|
sql="select obj_description(to_regclass(?), 'pg_class')";
|
arg=tableName;
|
break;
|
case MYSQL:
|
sql="select table_comment from information_schema.tables where table_schema=database() and table_name=?";
|
arg=tableName;
|
break;
|
case ORACLE:
|
sql="select comments from user_tab_comments where table_name=?";
|
arg=tableName.toUpperCase();
|
break;
|
case MICROSOFT:
|
sql="select cast(value as nvarchar(4000)) from sys.extended_properties where class=1 and major_id=object_id(?) and minor_id=0 and name='MS_Description'";
|
arg=tableName;
|
break;
|
default: // a dialect this switch was never told about must not inherit another one's catalog
|
throw new IllegalStateException("no table comment readback for dialect "+dialect);
|
}
|
try (final PreparedStatement statement=con.prepareStatement(sql)) {
|
statement.setString(1,arg);
|
return executeResultSet(statement, rs -> rs.next() ? rs.getString(1) : null);
|
}
|
}
|
|
// Statistics upkeep after an import is bounded and can be turned off: gathering statistics of
|
// a freshly loaded table is a full scan on oracle (dbms_stats defaults to AUTO_SAMPLE_SIZE,
|
// and the entries themselves live in the blob column it reads), which a multi-million entry
|
// backend would otherwise pay in full, with no way to cap or skip it, after import-ldif has
|
// already reported its final status.
|
static final String STATISTICS_PROPERTY="org.openidentityplatform.opendj.jdbc.statistics";
|
static final String STATISTICS_TIMEOUT_PROPERTY=STATISTICS_PROPERTY+".timeout";
|
private static final int STATISTICS_TIMEOUT_SECONDS_DEFAULT=600;
|
|
// A bulk load leaves the optimizer statistics of freshly created tables stale (a table that
|
// was never analyzed can make the planner badly misestimate the "where k>? order by k" cursor
|
// batches - see OpenIdentityPlatform/OpenDJ#859), so refresh them once the data is in place.
|
// Only the trees the import actually wrote are refreshed: rebuild-index imports a few index
|
// trees, and gathering statistics of the whole backend on its behalf is a full scan per
|
// table on oracle. Statistics upkeep is best-effort: a failure must not fail the import that
|
// produced the data, so failures are only logged - the return value makes them observable to tests.
|
boolean updateTableStatistics(Connection con, Collection<TreeName> trees) {
|
if (!Boolean.parseBoolean(System.getProperty(STATISTICS_PROPERTY,"true"))) {
|
logger.debug(LocalizableMessage.raw("jdbc: statistics refresh turned off by %s", STATISTICS_PROPERTY));
|
return false; // nothing was refreshed
|
}
|
final Dialect dialect=dialectOf(con);
|
if (dialect==null) { // no portable statistics refresh for other engines
|
return false; // nothing was refreshed: reporting success here would make the assertion of the tests vacuous
|
}
|
final int timeoutSeconds=clampSeconds(Integer.getInteger(STATISTICS_TIMEOUT_PROPERTY,STATISTICS_TIMEOUT_SECONDS_DEFAULT));
|
boolean allRefreshed=true;
|
for (final TreeName treeName : trees) {
|
final String tableName=getTableName(treeName);
|
// The statement is chosen inside the try, so that the guard of the default branch
|
// degrades to "this table was not refreshed" like every other failure here: the
|
// contract above is that a refresh which failed never fails the import that produced
|
// the data, and a throw escaping this loop would break it.
|
try {
|
final String sql;
|
final String[] args;
|
switch (dialect) {
|
case POSTGRES:
|
sql="analyze "+tableName;
|
args=NO_ARGS;
|
break;
|
case MYSQL:
|
sql="analyze table "+tableName;
|
args=NO_ARGS;
|
break;
|
case ORACLE:
|
sql="begin dbms_stats.gather_table_stats(user, ?); end;";
|
args=new String[]{tableName.toUpperCase()};
|
break;
|
case MICROSOFT:
|
sql="update statistics "+tableName;
|
args=NO_ARGS;
|
break;
|
default: // a dialect this switch was never told about must not inherit another one's statement
|
throw new IllegalStateException("no statistics refresh for dialect "+dialect);
|
}
|
try (final PreparedStatement statement=con.prepareStatement(sql)) {
|
// 0: wait without limit - and false where the driver would not take the cancel, which
|
// leaves the socket read timeout behind it as the only layer this refresh runs under
|
final boolean cancelArmed=timeoutSeconds>0 && setQueryTimeout(statement, timeoutSeconds);
|
for (int i=0;i<args.length;i++) {
|
statement.setString(i+1,args[i]);
|
}
|
// Under the bound of the statistics refresh rather than under a class of
|
// StatementBound, which would put its own value over one this statement has a
|
// property for - but under both layers of it all the same: on oracle this is
|
// dbms_stats.gather_table_stats, the engine whose session does not act on the
|
// break its driver sends, and it runs at the very end of a successful import,
|
// where a cancel that never arrives would park it with the data already
|
// committed and nothing left to report.
|
bounded(con, STATISTICS_TIMEOUT_PROPERTY, timeoutSeconds, cancelArmed, () -> {
|
if (logger.isTraceEnabled()) {
|
logger.trace(LocalizableMessage.raw("jdbc: %s",statement));
|
}
|
if (dialect==Dialect.MYSQL) { // mysql reports analyze problems as a result row, not an SQLException
|
try (final ResultSet rs=statement.executeQuery()) {
|
while (rs.next()) {
|
if ("error".equalsIgnoreCase(rs.getString("Msg_type"))) {
|
throw new SQLException(rs.getString("Msg_text"));
|
}
|
}
|
}
|
}else { // tolerates a statement that returns a result set, which execute() does not
|
statement.execute();
|
}
|
return null;
|
});
|
con.commit();
|
}
|
}catch (Exception e) {
|
try {
|
con.rollback();
|
} catch (SQLException e2) {}
|
allRefreshed=false;
|
logger.warn(LocalizableMessage.raw("jdbc: unable to refresh statistics of table %s (tree %s): %s",
|
tableName, treeName, stackTraceToSingleLineString(e)));
|
}
|
}
|
return allRefreshed;
|
}
|
|
@Override
|
public void removeStorageFiles() throws StorageRuntimeException {
|
final boolean isOpen=getStorageStatus().isWorking();
|
if (!isOpen) {
|
try {
|
open(AccessMode.READ_WRITE);
|
}catch (Exception e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
final Set<TreeName> trees=listTrees();
|
if (!trees.isEmpty()) {
|
try (final Connection con = getValidatedConnection()) {
|
try {
|
for (final TreeName treeName : trees) {
|
try (final PreparedStatement statement = con.prepareStatement("drop table " + getTableName(treeName))) {
|
execute(statement, StatementBound.BULK);
|
}
|
}
|
con.commit();
|
} catch (SQLException e) {
|
try {
|
con.rollback();
|
} catch (SQLException e2) {}
|
throw new StorageRuntimeException(e);
|
}
|
} catch (Exception e) {
|
throw new StorageRuntimeException(e);
|
}
|
// all tables are gone: forget the mappings so listTrees() consumers skip the dropped trees
|
for (final TreeName treeName : trees) {
|
tree2table.invalidate(treeName);
|
unstampableTrees.remove(treeName); // a table recreated later deserves a fresh stamp attempt
|
}
|
}
|
if (!isOpen) {
|
close();
|
}
|
}
|
|
//operation
|
/**
|
* {@inheritDoc}
|
* <p>
|
* A rolled back read is <em>not</em> replayed, as
|
* {@link org.opends.server.backends.pluggable.spi.Storage#read(ReadOperation)} requires: two of the read
|
* operations of this server are not idempotent, and replaying them corrupts their result rather than repairing
|
* it. {@code ExportJob} runs the whole export inside a single read and its LDIF writer is opened once, so a
|
* replay appends the entries already written instead of truncating the file; {@code VerifyJob} accumulates its
|
* counters in instance fields that no attempt resets, so a replay reports twice the entry count of the backend.
|
* Both are reachable while the server is online, since an export holds no more than a shared backend lock.
|
* A conflict therefore fails the read here, exactly as it did before the retry of {@link #write} was added.
|
* <p>
|
* A connection the database dropped is not replayed either, for the same reason - but it is reported to the
|
* pool, which cannot notice one on its own: a borrow inside the alive window of
|
* {@link CachedConnection#ALIVE_BYPASS_PROPERTY} asks the database nothing, so the statement that broke is the
|
* only place the drop is ever seen.
|
*/
|
@Override
|
public <T> T read(ReadOperation<T> readOperation) throws Exception {
|
//borrowed outside the try: a connect the pool could not make says nothing about the connections it
|
//holds - mysql reports a server at its connection limit as 08004, which is class 08 like a connection
|
//that broke - and distrusting the pool over it would validate every borrow under the very load the
|
//window exists for, against a server already refusing connections
|
final Connection con=getConnection();
|
boolean dropped=false;
|
try (con) {
|
try {
|
return readOperation.run(new ReadableTransactionImpl(con));
|
} catch (Exception e) {
|
//asked while this read still owns the connection: once the release below has returned it to
|
//the pool, another borrow may hold it and the driver would be answering about that one
|
dropped=isConnectionFailure(e,con);
|
if (dropped) {
|
//told before the release rather than after it: a rollback that never reaches the server -
|
//which is what pgjdbc does with a transaction it left IDLE - leaves the connection poolable,
|
//so the release puts the dropped connection back at the head of the deque, and a borrow
|
//racing the distrust would be handed it unvalidated
|
distrustPool();
|
}
|
throw e;
|
}
|
} catch (Exception e) {
|
//also the release of the connection: its rollback is the one round trip a read that found
|
//nothing makes, so it can be the only place a drop is ever seen
|
if (!dropped && isConnectionFailure(e)) {
|
distrustPool();
|
}
|
throw e;
|
}
|
}
|
|
/**
|
* {@inheritDoc}
|
* <p>
|
* {@link org.opends.server.backends.pluggable.spi.Storage#write(WriteOperation)} requires an implementation to
|
* retry a rolled back operation until it succeeds, and {@link WriteOperation} is documented as idempotent for
|
* exactly that reason; {@link org.opends.server.backends.pdb.PDBStorage#write(WriteOperation)} already does so
|
* on the conflict exception of its own engine. The loop is bounded here, unlike PDBStorage: the database may be
|
* shared with writers outside this server, so a conflict is not guaranteed to clear and failing the operation is
|
* better than never returning. It is bounded twice - by {@link #MAX_RETRIES} attempts and by the
|
* {@link #MAX_RETRY_WINDOW_NANOS} wall-clock window - because an attempt is not guaranteed to be short: a
|
* conflict an engine reports only after its own lock wait timeout would otherwise multiply that wait by the
|
* attempt count. A conflict that slow consumes the whole window in one attempt and is not replayed, which is
|
* what master did with it.
|
* <p>
|
* Only the operation itself is replayed: a failure of {@link #getConnection()} or of the implicit
|
* {@link Connection#close()} - which returns the connection to the pool after a rollback - leaves the loop, so
|
* that a completed write is never replayed because releasing its connection failed.
|
* <p>
|
* A connection the database dropped is replayed as well, on a connection the next attempt borrows of its own.
|
* That is what makes the alive window of {@link CachedConnection#ALIVE_BYPASS_PROPERTY} safe to leave on: a
|
* connection handed out unvalidated and found dead costs an attempt rather than the operation, and a write of
|
* the replication replay - which records a failed operation as applied and advances the server state past it,
|
* see #889 - never sees it. Only while nothing of the attempt may have been committed yet, though: see
|
* {@link #replayReason(Throwable, String, boolean, boolean, boolean)}.
|
*/
|
@Override
|
public void write(WriteOperation writeOperation) throws Exception {
|
final long giveUpAt=System.nanoTime()+MAX_RETRY_WINDOW_NANOS;
|
for (int attempt=1;;attempt++) {
|
Exception failure=null;
|
String driver=null;
|
boolean committing=false;
|
boolean dropped=false;
|
boolean partlyCommitted=false;
|
//borrowed outside the try, for the reason read() borrows outside it: a connect the pool could not
|
//make is not a connection of this pool that broke, and it leaves the loop as it always did
|
final Connection con=getConnection();
|
try (con) {
|
driver=driverNameOf(con);
|
final WriteableTransactionTransactionImpl txn=new WriteableTransactionTransactionImpl(con);
|
try {
|
writeOperation.run(txn);
|
committing=true;
|
con.commit();
|
return;
|
} catch (Exception e) {
|
try {
|
con.rollback();
|
} catch (SQLException ex) {
|
//joined to the failure rather than dropped: a rollback issued on a connection the
|
//database dropped is often the first place - and on a driver that reports a killed
|
//session as a plain vendor error, the only place - the drop is stated outright, and
|
//every classifier below reads the chains of this failure
|
e.addSuppressed(ex);
|
}
|
//asked while this attempt still owns the connection: the release below returns it to the
|
//pool, and the driver would then be answering about whichever borrow holds it next
|
dropped=isConnectionFailure(e,con);
|
if (dropped) {
|
//told before the release rather than after it, for the reason read() tells it there: a
|
//rollback that never reached the server leaves the connection poolable, so the release
|
//returns the dropped connection to the head of the deque, where a borrow racing this
|
//would be handed it unvalidated
|
distrustPool();
|
}
|
//rethrown, so that a failure of the implicit close() is suppressed into the failure being
|
//replayed rather than replacing it
|
failure=e;
|
throw e;
|
} finally { // the comment connection lives no longer than the trees it stamped, and no longer
|
// than the attempt that opened it: a replay stamps on a session of its own
|
partlyCommitted=txn.partlyCommitted;
|
try {
|
txn.stampSession.close();
|
} catch (RuntimeException e) {
|
//the stamp is a diagnostic aid and must not become the outcome of the write: an unchecked
|
//throw out of a driver's close() would otherwise replace the failure being unwound (JLS
|
//14.20.2) - the very one the replay is decided on and the only one that says what went
|
//wrong - or turn a transaction that has just committed into a failure of its own
|
if (failure!=null) {
|
failure.addSuppressed(e);
|
} else {
|
logger.trace(LocalizableMessage.raw("jdbc: unable to close the comment connection: %s",
|
stackTraceToSingleLineString(e)));
|
}
|
}
|
}
|
} catch (Exception e) {
|
//anything the operation did not throw comes from around it - the name of the driver, the
|
//transaction, or the implicit close() that returns the connection to the pool: none of them
|
//belongs to the replayed region
|
if (e!=failure) {
|
//a drop reported by the release of the connection still has to reach the pool, which has no
|
//other way of hearing of it. Only the chains of the failure can be asked for it now: the
|
//connection has been released, and whether it is closed is no longer this attempt's answer
|
if (isConnectionFailure(e)) {
|
distrustPool();
|
}
|
throw e;
|
}
|
}
|
//a drop the release of the connection reported still has to reach the pool, which has no other way
|
//of hearing of it. It is suppressed into the failure being unwound (JLS 14.20.3.1) rather than
|
//replacing it, which is what leaves e==failure and skips the branch above - and it is the very
|
//evidence replayReason() replays the attempt on, so the pool must not be told less than the loop
|
//acts on. The drop of the operation itself was reported before the release, above
|
if (!dropped && isConnectionFailure(failure)) {
|
distrustPool();
|
}
|
final String reason=replayReason(failure,driver,committing,partlyCommitted,dropped);
|
//System.nanoTime()-giveUpAt is the overflow safe form of the comparison
|
if (reason==null || attempt>=MAX_RETRIES || System.nanoTime()-giveUpAt>=0) {
|
throw failure;
|
}
|
//logged rather than silently absorbed, so that a deployment retrying most of its writes stays observable;
|
//one line per replay, since an add can emit nine of them and a stack trace each time reads as a failure
|
logger.warn(LocalizableMessage.raw("jdbc: replaying the transaction after %s, attempt %d of %d: %s",
|
reason, attempt, MAX_RETRIES, conflictSummary(failure, driver)));
|
if (logger.isTraceEnabled()) {
|
logger.trace("jdbc: the failure being replayed was %s", stackTraceToSingleLineString(failure));
|
}
|
try {
|
//randomized to spread the retries of the transactions that collided, growing to outlast contention
|
Thread.sleep(retryDelayMillis(attempt));
|
} catch (InterruptedException e) {
|
//sleep cleared the interrupt flag: restore it, and report the failure being retried rather than the
|
//interrupt, which would hide from the caller what actually went wrong
|
Thread.currentThread().interrupt();
|
failure.addSuppressed(e);
|
throw failure;
|
}
|
}
|
}
|
|
/**
|
* Why the operation of a {@link #write} is worth replaying, as the noun phrase the message reporting the replay
|
* names - or null for a failure this loop must not repeat.
|
* <p>
|
* A transaction conflict is replayable whichever phase reported it: the engine rolled the transaction back
|
* before it answered. It is read from the failure of the operation only, never from the release of the
|
* connection - see {@link #isRetryableConflict} - since the release runs after the outcome was decided and
|
* cannot make that claim for it. A connection the database dropped is replayable only while the transaction
|
* had not been committed yet. A drop reported by {@code commit()} leaves the outcome unknown - the server may
|
* have committed and died before the answer reached us - and replaying a write that in fact committed applies
|
* it twice, which is the very reason 40003 is one of {@link #NON_REPLAYABLE_ROLLBACK_STATES}.
|
* <p>
|
* Nothing is replayable once the attempt has committed part of its own work, whatever the failure says. The DDL
|
* of {@link WriteableTransactionTransactionImpl#openTree} and {@link WriteableTransactionTransactionImpl#deleteTree}
|
* commits inside {@link WriteOperation#run}, and mysql and oracle commit before a DDL statement whether asked
|
* to or not, so the attempt no longer rolls back as a whole - and {@link WriteOperation} is only idempotent in
|
* the database. {@code RootContainer.open} opens and registers every entry container of every base DN in one
|
* write: replayed after the trees of the first base DN were created and committed, it registers that base DN a
|
* second time and fails with ERR_ENTRY_CONTAINER_ALREADY_REGISTERED, which masks the failure that caused the
|
* replay and leaves the indexes of the previous attempt behind with their configuration listeners.
|
*
|
* @param committing whether the failure was reported by {@code commit()}, which leaves the outcome unknown
|
* @param partlyCommitted whether the attempt committed part of its work before it failed
|
* @param connectionClosed whether the driver closed the connection under the failure - evidence no SQLState
|
* carries on mssql-jdbc, which reports a killed session as S0001 and closes the connection behind it
|
*/
|
static String replayReason(Throwable failure, String driver, boolean committing, boolean partlyCommitted,
|
boolean connectionClosed) {
|
if (partlyCommitted) {
|
return null;
|
}
|
if (isRetryableConflict(failure, driver)) {
|
return "a conflict";
|
}
|
if (!committing && (connectionClosed || isConnectionFailure(failure))) {
|
return "a connection the database dropped";
|
}
|
return null;
|
}
|
|
/**
|
* Whether a failure says the connection is gone rather than the statement rejected, asked of the failure and of
|
* the connection it was raised on. A driver is not required to say so in a SQLState: mssql-jdbc reports a
|
* session killed by {@code KILL}, by the resource governor or by an availability group transition as error 596,
|
* 3980, 10054, 18456 or 4060, and {@code generateStateCode} maps none of them - with xopenStates off, which is
|
* its default, every one of them comes out as {@code "S"+errorState}, measured as S0001. What the driver does
|
* do is close the connection for any error of severity 20 and above, before it throws.
|
* <p>
|
* Asked only while the operation that failed still owns the connection: a released one is back in the pool and
|
* may already have been handed to another borrow, whose state it would then be answering about.
|
*/
|
static boolean isConnectionFailure(Throwable failure, Connection con) {
|
return isConnectionFailure(failure) || isClosed(con);
|
}
|
|
/** Whether the driver reports the connection as closed; one that cannot answer is taken as closed. */
|
private static boolean isClosed(Connection con) {
|
try {
|
return con.isClosed();
|
} catch (SQLException e) {
|
return true;
|
}
|
}
|
|
/**
|
* Whether a failure says the connection is gone rather than the statement rejected: the database dropped it,
|
* restarted, failed over, or the network did.
|
* <p>
|
* Both chains of the failure are walked, for the reason {@link #failureScope} walks both: a driver reports the
|
* error that says what happened as the next exception of a generic one at least as often as it reports it as
|
* the cause, and mssql-jdbc chains every error of a message it received that way. The suppressed exceptions are
|
* walked with them, since the rollback and the release of a connection report a drop there - a write whose
|
* operation failed for its own reasons carries the drop of its {@code close()} as a suppressed exception (JLS
|
* 14.20.3.1) rather than as a cause. The walk starts at the failure this class was handed because it reaches it
|
* wrapped in a {@link StorageRuntimeException}, and a caller such as {@code EntryContainer.addEntry} may wrap
|
* it once more.
|
*/
|
static boolean isConnectionFailure(Throwable failure) {
|
return firstLinkMatching(failure, WITH_THE_RELEASE, JDBCStorage::saysTheConnectionIsGone)!=null;
|
}
|
|
/**
|
* Whether {@link #firstLinkMatching} reads the suppressed exceptions along with the causes and the next
|
* exceptions. They are where the release of the connection reports what it saw - a rollback that failed as the
|
* attempt was unwound is suppressed into the failure being unwound (JLS 14.20.3.1) - so a question about the
|
* connection is asked of them, and a question about what the engine did with the transaction is not: the
|
* release runs after the outcome was decided, and cannot speak for it.
|
*/
|
private static final boolean WITH_THE_RELEASE=true;
|
private static final boolean WITHOUT_THE_RELEASE=false;
|
|
/**
|
* The first {@link SQLException} of the chains of a failure that answers the given question, or null where none
|
* does. Every classifier of this class walks the failure this way, so that none of them reads a chain the others
|
* act on: what makes a write replayable must also be what the pool is told about and what the replay logs.
|
*/
|
private static SQLException firstLinkMatching(Throwable failure, boolean withTheRelease,
|
Predicate<SQLException> matches) {
|
return firstLinkMatching(failure, withTheRelease, MAX_CHAIN_LINKS, matches);
|
}
|
|
/** The walk above, with the number of links it is allowed to look at. */
|
private static SQLException firstLinkMatching(Throwable failure, boolean withTheRelease, int links,
|
Predicate<SQLException> matches) {
|
final Deque<Throwable> pending=new ArrayDeque<>();
|
final Set<Throwable> seen=Collections.newSetFromMap(new IdentityHashMap<Throwable,Boolean>());
|
if (failure!=null) {
|
pending.push(failure);
|
}
|
while (!pending.isEmpty() && seen.size()<links) {
|
final Throwable e=pending.pop();
|
if (!seen.add(e)) { // a driver that chains an exception back to itself must not loop this walk
|
continue;
|
}
|
if (e.getCause()!=null) {
|
pending.push(e.getCause());
|
}
|
if (withTheRelease) {
|
for (final Throwable suppressed : e.getSuppressed()) {
|
pending.push(suppressed);
|
}
|
}
|
if (!(e instanceof SQLException)) {
|
continue;
|
}
|
final SQLException sqlException=(SQLException) e;
|
if (sqlException.getNextException()!=null) {
|
pending.push(sqlException.getNextException());
|
}
|
if (matches.test(sqlException)) {
|
return sqlException;
|
}
|
}
|
return null;
|
}
|
|
/**
|
* What one exception of the chain says on its own. The types are asked before the SQLState, the way
|
* {@link #scopeOf} asks them: they are what the JDBC contract gives a driver to say the connection is gone, and
|
* a driver that raises one of them has said so whatever state it filled in. Oracle reports ORA-03113, ORA-00028
|
* and ORA-01089 as {@link SQLRecoverableException} and happens to map them to 08006 as well; the type is what
|
* makes that robust rather than lucky.
|
*/
|
private static boolean saysTheConnectionIsGone(SQLException e) {
|
if (e instanceof SQLRecoverableException || e instanceof SQLNonTransientConnectionException
|
|| e instanceof SQLTransientConnectionException) {
|
return true;
|
}
|
final String state=String.valueOf(e.getSQLState());
|
return state.startsWith(CONNECTION_FAILURE_CLASS) || CONNECTION_FAILURE_STATES.contains(state);
|
}
|
|
/**
|
* Tells the pool of this backend that the database dropped a connection, so that the ones it still holds from
|
* before the drop are validated on their next borrow instead of being trusted for the rest of the alive window.
|
* A dropped connection is rarely alone: a restart, a failover or a network that went away takes every
|
* connection established before it, and the pool has no other way of hearing about any of them.
|
*/
|
private void distrustPool() {
|
// keyed like every other pool lookup of this storage: a drop reported against the string
|
// config names now would be filed on a pool holding none of this storage's connections
|
CachedConnection.distrustPool(poolKey());
|
}
|
|
/** Returns the randomized delay before the given attempt is replayed, doubling with each attempt up to a cap. */
|
static long retryDelayMillis(int attempt) {
|
final double bound=Math.min(MAX_SLEEP_ON_RETRY_MS, BASE_SLEEP_ON_RETRY_MS * (1 << Math.min(attempt-1, 5)));
|
return (long) (Math.random() * bound);
|
}
|
|
/**
|
* Returns whether the given failure carries a transaction conflict that replaying the operation can resolve.
|
* <p>
|
* The conflict is looked up along every chain of the failure, for the reason {@link #isConnectionFailure} walks
|
* them all: it reaches this class wrapped - a deadlock in {@code put} arrives as
|
* {@code StorageRuntimeException(SQLException)}, and a caller such as {@code EntryContainer.addEntry} may wrap it
|
* once more - and a driver reports the error that says what happened as the next exception of a generic one at
|
* least as often as it reports it as the cause.
|
* <p>
|
* The standard class 40 states carry the conflict of most engines - 40P01 for PostgreSQL, 40001 for SQL Server
|
* and for MySQL, whose driver replaces the server side HY000 of a deadlock and of a lock wait timeout with
|
* 40001 - but not of all of them, so the vendor error numbers are consulted as well, keyed by the driver in the
|
* same way {@code getTableDialect} keys the column types. They cannot be matched driver-independently: Oracle
|
* reports a deadlock as ORA-00060 with SQLState 61000, and gives 1205 to a fatal "not a data file" error that
|
* no replay can resolve, while 1205 is exactly the deadlock victim of SQL Server. The SQL Server number is
|
* matched beyond its class 40 state because a deployment may add {@code xopenStates=true} to its connection
|
* URL, which reports the same deadlock as 42000. MySQL needs no number of its own, since its driver has already
|
* mapped both conditions into class 40; see {@link #NON_REPLAYABLE_ROLLBACK_STATES} for the two class 40 states
|
* that are excluded from that match.
|
*/
|
static boolean isRetryableConflict(Throwable t, String driver) {
|
// without the suppressed exceptions, unlike isConnectionFailure(): a conflict is replayed whichever phase
|
// reported it, on the strength of the engine having rolled the transaction back before it answered - and
|
// the release of the connection runs after the outcome was decided and cannot make that claim. A class 40
|
// raised there would otherwise replay a transaction commit() left in doubt, which is what the committing
|
// guard of replayReason() exists to prevent
|
return firstLinkMatching(t, WITHOUT_THE_RELEASE, e -> isConflict(e, driver))!=null;
|
}
|
|
private static boolean isConflict(SQLException e, String driver) {
|
final String state=String.valueOf(e.getSQLState());
|
if (state.startsWith("40") && !NON_REPLAYABLE_ROLLBACK_STATES.contains(state)) {
|
return true;
|
}
|
final String driverName=String.valueOf(driver);
|
if (driverName.contains("oracle")) {
|
return e.getErrorCode()==ORACLE_DEADLOCK_DETECTED;
|
} else if (driverName.contains("microsoft")) {
|
return e.getErrorCode()==MSSQL_DEADLOCK_VICTIM;
|
}
|
return false;
|
}
|
|
/**
|
* Returns the SQLState and vendor error number of the exception a replay was decided on, so that a replay can be
|
* logged without a stack trace on every attempt. That line is the only record a replay leaves, so it names the
|
* link the decision was taken on rather than the first {@link SQLException} of the failure: a write whose
|
* operation failed for its own reasons and whose release then reported a drop is replayed on the class 08
|
* suppressed into it, and naming the state of the rejected statement instead would describe a replay that did
|
* not happen. Falls back to the first SQLException of the failure, and to the failure itself where it carries
|
* none.
|
*/
|
static String conflictSummary(Throwable failure, String driver) {
|
// asked in the order replayReason() asks it, and of the same chains, so that the line names the link the
|
// decision was taken on rather than one that merely resembles it
|
SQLException named=firstLinkMatching(failure, WITHOUT_THE_RELEASE, e -> isConflict(e, driver));
|
if (named==null) {
|
named=firstLinkMatching(failure, WITH_THE_RELEASE, JDBCStorage::saysTheConnectionIsGone);
|
}
|
if (named==null) {
|
// without the release, so that the line names the statement that failed rather than the rollback
|
// behind it: this is the fallback of a replay decided on isClosed(con) alone, where neither chain
|
// carries a verdict, and the walk reaches the suppressed exceptions before the cause
|
named=firstLinkMatching(failure, WITHOUT_THE_RELEASE, e -> true);
|
}
|
return named==null
|
? String.valueOf(failure)
|
: "SQLState "+named.getSQLState()+", error "+named.getErrorCode()+": "+named.getMessage();
|
}
|
|
static final byte[] NULL=new byte[]{(byte)0};
|
|
static byte[] real2db(byte[] real) {
|
return real.length==0?NULL:real;
|
}
|
static byte[] db2real(byte[] db) {
|
return Arrays.equals(NULL,db)?new byte[0]:db;
|
}
|
|
final LoadingCache<ByteBuffer,String> key2hash = Caffeine.newBuilder()
|
.softValues()
|
.build(key -> {
|
try {
|
final MessageDigest md = MessageDigest.getInstance("SHA-512");
|
final byte[] messageDigest = md.digest(key.array());
|
final StringBuilder hashtext = new StringBuilder(128);
|
for (byte b : messageDigest) {
|
String hex = Integer.toHexString(0xff & b);
|
if (hex.length() == 1) hashtext.append('0');
|
hashtext.append(hex);
|
}
|
return hashtext.toString();
|
} catch (NoSuchAlgorithmException e) {
|
throw new RuntimeException(e);
|
}
|
});
|
|
/**
|
* Returns the placeholder to compare against the {@code h} column, casting it where the driver would
|
* otherwise bind a value of the wrong type.
|
* <p>
|
* The SQL Server driver sends {@link PreparedStatement#setString} parameters as NVARCHAR, and under a SQL
|
* collation comparing the {@code char(128)} column against an NVARCHAR value converts the column instead of
|
* the value: the primary key can no longer be sought, so every statement scans the whole table rather than
|
* reading one row. The upsert runs that scan under HOLDLOCK, which range-locks the entire table instead of
|
* the single key being written - the lock footprint that lets concurrent writers deadlock (error 1205).
|
* Casting the parameter back to char keeps the comparison seekable.
|
*/
|
static String hashParam(Connection con) {
|
return driverNameOf(con).contains("microsoft") ? "cast(? as char(128))" : "?";
|
}
|
|
class ReadableTransactionImpl implements ReadableTransaction {
|
final Connection con;
|
/**
|
* The class the statements of this transaction take. It follows who runs them rather than
|
* what they look like: an import issues the same select and the same upsert a client
|
* operation does, but nobody is waiting on it - and on mssql it works the table unindexed,
|
* {@code k} being a {@code varbinary(max)} that cannot be an index key - so bounding an
|
* import as an entry read fails an import that ran to the end before this bound existed.
|
* The catalog lookups of {@code openTree()} keep the operation class whoever runs them: they
|
* read a data dictionary rather than the data, so a wait there is another session's metadata
|
* lock, which is one of the waits this bound exists to end.
|
*/
|
final StatementBound bound;
|
boolean isReadOnly=true;
|
|
public ReadableTransactionImpl(Connection con) {
|
this(con, StatementBound.OPERATION);
|
}
|
|
ReadableTransactionImpl(Connection con, StatementBound bound) {
|
this.con=con;
|
this.bound=bound;
|
}
|
|
@Override
|
public ByteString read(TreeName treeName, ByteSequence key) {
|
// the non-enrolling name: a read must not put a tree this backend does not own - the
|
// shared compressed schema tree of #873 - up for removal
|
final String tableName=readTableName(treeName);
|
try (final PreparedStatement statement=con.prepareStatement("select v from "+tableName+" where h="+hashParam(con)+" and k=?")){
|
statement.setString(1,key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2,real2db(key.toByteArray()));
|
return executeResultSet(statement, bound, rc -> rc.next() ? valueOfRow(rc, tableName) : null);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
|
@Override
|
public Cursor<ByteString, ByteString> openCursor(TreeName treeName) {
|
return new CursorImpl(isReadOnly,con,treeName,bound);
|
}
|
|
/**
|
* {@inheritDoc}
|
* <p>
|
* The batches of such a cursor are bulk statements however ordinary they look: nobody is
|
* waiting on the walk, and on mssql it is not even a walk along an index - {@code k} is a
|
* {@code varbinary(max)} there, which cannot be an index key, so every batch is a scan and
|
* a sort of the table. Bounding those as entry reads aborted an export or a rebuild that
|
* ran to the end before this bound existed.
|
*/
|
@Override
|
public Cursor<ByteString, ByteString> openBulkCursor(TreeName treeName) {
|
return new CursorImpl(isReadOnly,con,treeName,StatementBound.BULK);
|
}
|
|
/**
|
* {@inheritDoc}
|
* <p>
|
* Bulk whoever asks: {@code select count(*)} is a scan of the whole table on every engine
|
* here, so what it takes follows the size of the backend rather than the work of the caller
|
* that happens to ask. Its callers are administrative either way - {@code dbtest} through
|
* {@code BackendStat}, and the counts {@code verify-index} reports - so the override costs a
|
* client operation nothing. It is not the count behind {@code NOTE_BACKEND_STARTED}: that one
|
* is {@code BackendImpl.getEntryCount()} through {@code RootContainer.getEntryCount()}, which
|
* sums {@code id2childrenCount} and never reaches this method.
|
* <p>
|
* One of the places the class of the transaction is overridden downwards, the others being
|
* {@link #openBulkCursor(TreeName)}, {@link CursorImpl#positionToLastKey()} and the DDL a
|
* write transaction issues - the {@code create table} and the three {@code create index} of
|
* {@code openTree()}, the {@code delete from} of {@code clearTree()} and the {@code drop
|
* table} of {@code deleteTree()} - which is where an operation-class transaction, the one
|
* {@code write()} runs with, can take the shared backstop of its connection off. The count
|
* is deliberately not given here: whoever audits that list has to read it off the class
|
* rather than trust a number that a later hard-coded {@code BULK} would leave stale.
|
*/
|
@Override
|
public long getRecordCount(TreeName treeName) {
|
try (final PreparedStatement statement=con.prepareStatement("select count(*) from "+readTableName(treeName))){
|
return executeResultSet(statement, StatementBound.BULK, rc -> rc.next() ? rc.getLong(1) : 0);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
|
@Override
|
public boolean treeExists(TreeName treeName) {
|
return isExistsTable(treeName);
|
}
|
|
// Readable, not writeable: the caller that asks about a tree this backend does not own is
|
// the compressed schema migration (#873), which probes the shared tree from the writeable
|
// transaction of RootContainer.open() but must not create or enrol it. Answering that from
|
// the readable transaction keeps the probe available to every reader, and costs nothing:
|
// the writeable one inherits it.
|
boolean isExistsTable(TreeName treeName) {
|
final String tableName = readTableName(treeName);
|
// the catalog lookup guarding a create table is bounded as the operation it is, not as
|
// the bulk statement it guards, and not as the class of the transaction that happens to
|
// ask: it reads a data dictionary rather than the data, so a wait here is the metadata
|
// lock of another session
|
try {
|
return bounded(con, StatementBound.OPERATION, () -> {
|
final DatabaseMetaData metaData = con.getMetaData();
|
// asked of the catalog by name: openTree(createOnDemand) calls this for every tree
|
// of the backend - about 25 of them for a stock suffix, on every open - and listing
|
// every table of the database each time costs the whole catalog once per tree, on a
|
// database this backend may well be sharing with something else
|
try (final ResultSet rs = metaData.getTables(null, null,
|
storedIdentifier(metaData, tableName), new String[]{"TABLE"})) {
|
while (rs.next()) {
|
// the name still has to be compared: "_" is a single-character wildcard in a
|
// metadata pattern, so "opendj_<hash>" also matches a table named "opendjX<hash>"
|
if (tableName.equalsIgnoreCase(rs.getString("TABLE_NAME"))) {
|
return true;
|
}
|
}
|
}
|
return false;
|
});
|
} catch (Exception e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
}
|
/**
|
* A transaction able to write, unless the storage was opened read-only: then it may open an existing tree and
|
* read it, and every mutating operation throws {@link ReadOnlyStorageException} instead.
|
* <p>
|
* The mode is checked per operation rather than refused here, because {@code RootContainer.open(AccessMode)}
|
* asks for a write transaction even in read-only mode - that is where it opens the compressed schema and the
|
* entry containers - so refusing to hand one out failed the offline {@code export-ldif}, {@code verify-index}
|
* and {@code backendstat} before they read anything (#874). Both other storages of this server already have
|
* this shape: {@code PDBStorage.ReadOnlyStorageImpl} and {@code CASStorage.TransactionImpl.checkReadOnly()}.
|
*/
|
private final class WriteableTransactionTransactionImpl extends ReadableTransactionImpl implements WriteableTransaction {
|
|
// Shared by every table this transaction stamps: opening a backend opens all its trees,
|
// and each stamp of its own connection would be a physical connect of its own. Closed by
|
// write() (and by ImporterImpl.close()) when the transaction is done with.
|
final StampSession stampSession=new StampSession();
|
|
/**
|
* Whether this transaction has committed part of its own work, which takes the attempt out of the
|
* replay of {@link JDBCStorage#write}: what it did no longer rolls back as a whole, and a
|
* {@link WriteOperation} is only idempotent in the database.
|
* <p>
|
* Raised by {@link #commitStatement} alone, which is what every statement of this transaction that
|
* commits goes through - never once for a method that may issue one: a catalog read deciding that the
|
* statement is not needed commits nothing, and a transaction the engine rolled back whole is still worth
|
* replaying. Which side of the statement the flag goes up on is the engine's answer, see there.
|
*/
|
boolean partlyCommitted;
|
|
public WriteableTransactionTransactionImpl(Connection con) {
|
this(con, StatementBound.OPERATION);
|
}
|
|
WriteableTransactionTransactionImpl(Connection con, StatementBound bound) {
|
super(con, bound);
|
//captured once rather than read per operation: the access mode of the storage is mutable state -
|
//ImporterImpl reopens the storage READ_WRITE under its caller - and a transaction has to keep the mode
|
//it was created with. It also drives isReadOnly, so that a cursor this transaction opens refuses
|
//delete() as well.
|
isReadOnly = !accessMode.isWriteable();
|
}
|
|
void checkReadOnly() {
|
if (isReadOnly) {
|
throw new ReadOnlyStorageException();
|
}
|
}
|
|
/**
|
* Issues a statement that ends in a commit, raising {@link #partlyCommitted} at the moment the attempt
|
* stops rolling back as a whole.
|
* <p>
|
* mysql and oracle commit before a DDL statement whether asked to or not, so there the work behind it is
|
* committed by the statement itself and the flag has to be up before it is issued: the statement that
|
* fails has committed everything before it just as surely as the one that succeeds. postgresql and sql
|
* server run DDL inside the transaction, and a DML statement commits of its own accord nowhere - one that
|
* fails there has committed nothing, {@link JDBCStorage#write} rolls the attempt back whole, and a flag
|
* raised in front of it would take a conflict the engine itself undid out of the replay. On those the
|
* flag goes up in front of the commit instead, which is the call that leaves the outcome of the
|
* transaction unknown when it fails.
|
*
|
* @param ddl whether the statement is a DDL one, which two of the four engines commit before
|
*/
|
private void commitStatement(String sql, boolean ddl) throws SQLException {
|
partlyCommitted|=ddl && commitsBeforeDdl();
|
// Bulk, whatever class the transaction itself carries: every statement issued through here is
|
// one of the ones #877 names as overridden downwards - the create table and the three create
|
// index of openTree(), the delete from of clearTree() and the drop table of deleteTree() -
|
// and nobody is waiting on any of them.
|
try (final PreparedStatement statement=con.prepareStatement(sql)) {
|
execute(statement, StatementBound.BULK);
|
partlyCommitted=true; // a commit that fails leaves the outcome unknown, which is no more replayable
|
con.commit();
|
}
|
}
|
|
/** Whether this engine commits the transaction before a DDL statement whether asked to or not. */
|
private boolean commitsBeforeDdl() {
|
final String driverName=driverNameOf(con);
|
return driverName.contains("mysql") || driverName.contains("oracle");
|
}
|
|
String getTableDialect() {
|
if (driverNameOf(con).contains("oracle")) {
|
return "h char(128),k raw(2000),v blob,primary key(h,k)";
|
}else if (driverNameOf(con).contains("mysql")) {
|
return "h char(128),k varbinary(255),v longblob,primary key(h,k)";
|
}else if (driverNameOf(con).contains("microsoft")) {
|
return "h char(128),k varbinary(max),v image,primary key(h)";
|
}
|
return "h char(128),k bytea,v bytea,primary key(h,k)";
|
}
|
|
@Override
|
public void openTree(TreeName treeName, boolean createOnDemand) {
|
if (createOnDemand) {
|
checkReadOnly();
|
// Every statement below is a DDL that commits, and each raises partlyCommitted through
|
// commitStatement() rather than once for the method: every one of them is guarded by a
|
// catalog read, so on an existing backend this method issues nothing at all. Raising the
|
// flag for a catalog read that commits nothing would make the whole attempt unreplayable -
|
// the conflict replay of #867 as much as the drop replay, since replayReason() reads the
|
// flag before it asks anything else - and RootContainer.open() opens every tree of every
|
// base DN in a single write, whose first act is one of these.
|
if (!isExistsTable(treeName)) {
|
try {
|
commitStatement("create table "+getTableName(treeName)+" ("+getTableDialect()+")", true);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
// CursorImpl iterates with "where k>? order by k" batches: primary key (h,k) cannot serve them
|
final String driverName=driverNameOf(con);
|
final String tableName=getTableName(treeName);
|
if (driverName.contains("postgres")) {
|
try {
|
// asked although postgresql has "create index if not exists": that statement commits
|
// whether it creates anything or not, and this is the engine of every default
|
// deployment - unguarded, it would take every write that opens a tree out of the
|
// conflict replay, RootContainer.open() and its ~25 trees per suffix included
|
if (!isExistsIndex(tableName,"k_"+tableName.substring("opendj_".length()))) {
|
commitStatement("create index if not exists k_"+tableName.substring("opendj_".length())+" on "+tableName+" (k)", true);
|
}
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}else if (driverName.contains("mysql")) {
|
try {
|
if (!isExistsIndex(tableName,"k_"+tableName.substring("opendj_".length()))) { // mysql has no "create index if not exists"
|
commitStatement("create index k_"+tableName.substring("opendj_".length())+" on "+tableName+" (k)", true);
|
}
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}else if (driverName.contains("oracle")) {
|
try {
|
// oracle has no "create index if not exists"; unquoted identifiers are stored in uppercase
|
if (!isExistsIndex(tableName.toUpperCase(),"k_"+tableName.substring("opendj_".length()))) {
|
commitStatement("create index k_"+tableName.substring("opendj_".length())+" on "+tableName+" (k)", true);
|
}
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
// mssql: k is varbinary(max), which cannot be an index key column - cursor batches stay unindexed there
|
// the dialect is taken off this transaction's own connection: finding it out must
|
// not cost a borrow from a pool this thread is already holding a connection of
|
commentTable(treeName, dialectOf(con), stampSession);
|
}
|
}
|
|
boolean isExistsIndex(String tableName, String indexName) throws SQLException {
|
return bounded(con, StatementBound.OPERATION, () -> {
|
// approximate=true: with false the oracle driver runs ANALYZE on every call
|
try (final ResultSet rs = con.getMetaData().getIndexInfo(null, null, tableName, false, true)) {
|
while (rs.next()) {
|
if (indexName.equalsIgnoreCase(rs.getString("INDEX_NAME"))) {
|
return true;
|
}
|
}
|
}
|
return false;
|
});
|
}
|
|
public void clearTree(TreeName treeName) {
|
checkReadOnly();
|
try { // the commit takes the attempt out of the replay: it commits the delete, and everything before it
|
commitStatement("delete from "+getTableName(treeName), false);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
|
@Override
|
public void deleteTree(TreeName treeName) {
|
checkReadOnly();
|
if (isExistsTable(treeName)) {
|
try {
|
commitStatement("drop table " + getTableName(treeName), true);
|
} catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
// forget the mapping so listTrees() consumers (updateTableStatistics) skip the dropped table
|
tree2table.invalidate(treeName);
|
unstampableTrees.remove(treeName); // a table recreated later deserves a fresh stamp attempt
|
}
|
|
@Override
|
public void put(TreeName treeName, ByteSequence key, ByteSequence value) {
|
checkReadOnly();
|
try {
|
upsert(treeName, key, value);
|
} catch (SQLException e) {
|
//StorageRuntimeException, like read() and delete(): EntryContainer passes that type through unchanged,
|
//while any other runtime exception is turned into an opaque ERR_UNCHECKED_EXCEPTION before it can be
|
//classified as a conflict
|
throw new StorageRuntimeException(e);
|
}
|
}
|
|
boolean upsert(TreeName treeName, ByteSequence key, ByteSequence value) throws SQLException {
|
final String driverName=driverNameOf(con);
|
if (driverName.contains("postgres")) { //postgres upsert
|
try (final PreparedStatement statement = con.prepareStatement("insert into " + getTableName(treeName) + " (h,k,v) values (?,?,?) ON CONFLICT (h, k) DO UPDATE set v=excluded.v")) {
|
statement.setString(1, key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2, real2db(key.toByteArray()));
|
statement.setBytes(3, value.toByteArray());
|
return (execute(statement, bound) == 1 && statement.getUpdateCount() > 0);
|
}
|
}else if (driverName.contains("mysql")) { //mysql upsert
|
try (final PreparedStatement statement = con.prepareStatement("insert into " + getTableName(treeName) + " (h,k,v) values (?,?,?) as new ON DUPLICATE KEY UPDATE v=new.v")) {
|
statement.setString(1, key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2, real2db(key.toByteArray()));
|
statement.setBytes(3, value.toByteArray());
|
return (execute(statement, bound) == 1 && statement.getUpdateCount() > 0);
|
}
|
}else if (driverName.contains("oracle")) { //ANSI MERGE without ;
|
try (final PreparedStatement statement = con.prepareStatement("merge into " + getTableName(treeName) + " old using (select ? h,? k,? v from dual) new on (old.h=new.h and old.k=new.k) WHEN MATCHED THEN UPDATE SET old.v=new.v WHEN NOT MATCHED THEN INSERT (h,k,v) VALUES (new.h,new.k,new.v)")) {
|
statement.setString(1, key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2, real2db(key.toByteArray()));
|
statement.setBytes(3, value.toByteArray());
|
return (execute(statement, bound) == 1 && statement.getUpdateCount() > 0);
|
}
|
}else if (driverName.contains("microsoft")) { //ANSI MERGE with ; WITH (HOLDLOCK) makes the upsert atomic: without it SQL Server MERGE can race two concurrent NOT MATCHED inserts of the same key into a PRIMARY KEY violation. UPDLOCK is required on top of it: with HOLDLOCK alone the search phase takes a shared lock that the WHEN MATCHED update then has to convert to an exclusive one, so two concurrent upserts of the same key deadlock on the conversion; an update lock is taken right away and makes the second transaction wait instead. h is cast back to char so that the join can seek the primary key instead of scanning the whole table under those locks, see hashParam()
|
try (final PreparedStatement statement = con.prepareStatement("merge into " + getTableName(treeName) + " WITH (HOLDLOCK, UPDLOCK) old using (select cast(? as char(128)) h,? k,? v) new on (old.h=new.h and old.k=new.k) WHEN MATCHED THEN UPDATE SET old.v=new.v WHEN NOT MATCHED THEN INSERT (h,k,v) VALUES (new.h,new.k,new.v);")) {
|
statement.setString(1, key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2, real2db(key.toByteArray()));
|
statement.setBytes(3, value.toByteArray());
|
return (execute(statement, bound) == 1 && statement.getUpdateCount() > 0);
|
}
|
}else { //ANSI SQL: try update before insert with not exists
|
return update(treeName,key,value) || insert(treeName,key,value);
|
}
|
}
|
|
boolean insert(TreeName treeName, ByteSequence key, ByteSequence value) throws SQLException {
|
try (final PreparedStatement statement = con.prepareStatement("insert into " + getTableName(treeName) + " (h,k,v) select ?,?,? where not exists (select 1 from "+getTableName(treeName)+" where h=? and k=? )")) {
|
statement.setString(1, key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2, real2db(key.toByteArray()));
|
statement.setBytes(3, value.toByteArray());
|
statement.setString(4, key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(5, real2db(key.toByteArray()));
|
return (execute(statement, bound)==1 && statement.getUpdateCount()>0);
|
}
|
}
|
|
boolean update(TreeName treeName, ByteSequence key, ByteSequence value) throws SQLException {
|
try (final PreparedStatement statement=con.prepareStatement("update "+getTableName(treeName)+" set v=? where h=? and k=?")){
|
statement.setBytes(1,value.toByteArray());
|
statement.setString(2,key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(3,real2db(key.toByteArray()));
|
return (execute(statement, bound)==1 && statement.getUpdateCount()>0);
|
}
|
}
|
|
@Override
|
public boolean update(TreeName treeName, ByteSequence key, UpdateFunction f) {
|
//checked before the read, so that a read-only transaction reports the mode rather than the value it
|
//computed being equal to the stored one
|
checkReadOnly();
|
final ByteString oldValue=read(treeName,key);
|
final ByteSequence newValue=f.computeNewValue(oldValue);
|
if (Objects.equals(newValue, oldValue))
|
{
|
return false;
|
}
|
if (newValue == null)
|
{
|
return delete(treeName, key);
|
}
|
put(treeName,key,newValue);
|
return true;
|
}
|
|
@Override
|
public boolean delete(TreeName treeName, ByteSequence key) {
|
checkReadOnly();
|
try (final PreparedStatement statement=con.prepareStatement("delete from "+getTableName(treeName)+" where h="+hashParam(con)+" and k=?")){
|
statement.setString(1,key2hash.get(ByteBuffer.wrap(key.toByteArray())));
|
statement.setBytes(2,real2db(key.toByteArray()));
|
return (execute(statement, bound)==1 && statement.getUpdateCount()>0);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
}
|
|
static int compareKeys(byte[] key1, byte[] key2) {
|
return ByteString.wrap(key1).compareTo(key2, 0, key2.length);
|
}
|
|
// Iterates in batches via keyset pagination ("where k>? order by k limit n"):
|
// scrollable ResultSet is not an option, the postgres/mysql drivers materialize it entirely in memory.
|
// Batches start at "fetchsize.initial" and grow geometrically to "fetchsize" while the reads stay
|
// sequential: most cursors read only a few rows, and eagerly fetching the maximum made every
|
// repositioning transfer "fetchsize" rows over the network (#860).
|
final class CursorImpl implements Cursor<ByteString, ByteString> {
|
final Connection con;
|
final TreeName treeName;
|
final String tableName;
|
// the enrolling name, resolved once and only if this cursor ever deletes
|
String writeTableName;
|
final boolean isReadOnly;
|
final int batchSize=Math.max(1,Integer.getInteger("org.openidentityplatform.opendj.jdbc.fetchsize",1000));
|
final int initialBatchSize=Math.min(batchSize,Math.max(1,Integer.getInteger("org.openidentityplatform.opendj.jdbc.fetchsize.initial",32)));
|
int nextBatchSize=initialBatchSize;
|
long fetchCount;
|
final String limitClause;
|
|
final ArrayDeque<byte[][]> buffer=new ArrayDeque<>();
|
byte[] currentKeyDb;
|
ByteString currentKey;
|
ByteString currentValue;
|
boolean defined;
|
|
// The class of the statements this cursor issues, from whoever opened it: a search walks its
|
// index and has a client waiting, while an import, an export or a rebuild walks a whole tree
|
// with nobody waiting - and on mssql it walks it unindexed either way. It is not read off the
|
// shape of the statement, because the opening batch of every cursor is the same
|
// unconditioned "order by k" that positionToLastKey() issues, search or not.
|
final StatementBound batchBound;
|
|
public CursorImpl(boolean isReadOnly, Connection con, TreeName treeName, StatementBound batchBound) {
|
this.isReadOnly=isReadOnly;
|
this.con=con;
|
this.treeName=treeName;
|
// the read statements below take the non-enrolling name: a cursor is how the migration
|
// of #873 reads the shared tree, and reading a tree must not put it up for removal
|
this.tableName=readTableName(treeName);
|
this.batchBound=batchBound;
|
this.limitClause=((CachedConnection)con).parent.getClass().getName().contains("mysql")
|
? " limit ?,?" : " offset ? rows fetch next ? rows only";
|
}
|
|
int adaptiveBatchSize() {
|
final int size=nextBatchSize;
|
nextBatchSize=Math.min(batchSize,size*4);
|
return size;
|
}
|
|
/**
|
* Reads one batch of the cursor. The class of the bound is the caller's: a batch taken
|
* along the index of the tree for a client is an operation, while a batch that has to look
|
* at the whole table to answer - the one behind {@link #positionToLastKey()} - and every
|
* batch of a cursor an import or a rebuild walks ({@link #batchBound}) is bulk work, and
|
* the two cannot share a value.
|
*/
|
boolean fetchBatch(String condition, byte[] dbKey, long offset, boolean descending, int limit, StatementBound bound) {
|
fetchCount++;
|
buffer.clear();
|
try (final PreparedStatement statement=con.prepareStatement("select k,v from "+tableName
|
+(condition!=null?" where k"+condition+"?":"")
|
+" order by k"+(descending?" desc":"")+limitClause)){
|
int i=1;
|
if (condition!=null) {
|
statement.setBytes(i++,dbKey);
|
}
|
statement.setLong(i++,offset);
|
statement.setLong(i,limit);
|
return executeResultSet(statement, bound, rc -> {
|
while (rc.next()) {
|
buffer.add(new byte[][]{rc.getBytes(1),valueOfRow(rc.getBytes(2),tableName)});
|
}
|
return !buffer.isEmpty();
|
});
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
|
void advanceFromBuffer() {
|
final byte[][] row=buffer.poll();
|
currentKeyDb=row[0];
|
currentKey=ByteString.wrap(db2real(row[0]));
|
currentValue=ByteString.wrap(row[1]);
|
defined=true;
|
}
|
|
@Override
|
public boolean next() {
|
if (buffer.isEmpty() && !fetchBatch(currentKeyDb==null?null:">",currentKeyDb,0,false,adaptiveBatchSize(),batchBound)) {
|
defined=false;
|
return false;
|
}
|
advanceFromBuffer();
|
return true;
|
}
|
|
@Override
|
public boolean isDefined() {
|
return defined;
|
}
|
|
@Override
|
public ByteString getKey() throws NoSuchElementException {
|
if (!defined) {
|
throw new NoSuchElementException();
|
}
|
return currentKey;
|
}
|
|
@Override
|
public ByteString getValue() throws NoSuchElementException {
|
if (!defined) {
|
throw new NoSuchElementException();
|
}
|
return currentValue;
|
}
|
|
@Override
|
public void delete() throws NoSuchElementException, UnsupportedOperationException {
|
if (!defined) {
|
throw new NoSuchElementException();
|
}
|
if (isReadOnly) {
|
throw new UnsupportedOperationException();
|
}
|
if (writeTableName==null) {
|
// the enrolling name, unlike the read statements above: this writes to the tree, so
|
// it is one this backend owns, and removeStorageFiles() has to know about it
|
writeTableName=getTableName(treeName);
|
}
|
try (final PreparedStatement statement=con.prepareStatement("delete from "+writeTableName+" where h="+hashParam(con)+" and k=?")){
|
statement.setString(1,key2hash.get(ByteBuffer.wrap(db2real(currentKeyDb))));
|
statement.setBytes(2,currentKeyDb);
|
execute(statement, batchBound);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
|
@Override
|
public void close() {
|
buffer.clear();
|
defined=false;
|
}
|
|
@Override
|
public boolean positionToKeyOrNext(ByteSequence key) {
|
final byte[] target=real2db(key.toByteArray());
|
// Forward repositioning within the already-fetched range is served from the buffer: buffered
|
// rows are the contiguous sorted rows following the current one (byte order matches the
|
// database binary collation), so the first row >= target is guaranteed to be among them.
|
if (!buffer.isEmpty() && currentKeyDb!=null
|
&& compareKeys(target,currentKeyDb)>0
|
&& compareKeys(target,buffer.peekLast()[0])<=0) {
|
while (compareKeys(buffer.peek()[0],target)<0) {
|
buffer.poll();
|
}
|
advanceFromBuffer();
|
return true;
|
}
|
if (!buffer.isEmpty()) { // jumped outside the buffered range: random access, back to small batches
|
nextBatchSize=initialBatchSize;
|
}
|
if (fetchBatch(">=",target,0,false,adaptiveBatchSize(),batchBound)) {
|
advanceFromBuffer();
|
return true;
|
}
|
defined=false;
|
return false;
|
}
|
|
@Override
|
public boolean positionToKey(ByteSequence key) {
|
final byte[] real=key.toByteArray();
|
// The row is wrapped inside the handler rather than after it, so that null keeps meaning
|
// "no such key" and only that: a row whose v is null - which the schema allows, however
|
// this backend writes it - has to fail here as it fails in read(), rather than report a
|
// key that exists as absent. Both go through valueOfRow(), which is where that failure
|
// is named.
|
final ByteString value;
|
try (final PreparedStatement statement=con.prepareStatement("select v from "+tableName+" where h="+hashParam(con)+" and k=?")){
|
statement.setString(1,key2hash.get(ByteBuffer.wrap(real)));
|
statement.setBytes(2,real2db(real));
|
value=executeResultSet(statement, batchBound, rc -> rc.next() ? valueOfRow(rc, tableName) : null);
|
}catch (SQLException e) {
|
throw new StorageRuntimeException(e);
|
}
|
if (value!=null) {
|
buffer.clear();
|
nextBatchSize=initialBatchSize;
|
currentKeyDb=real2db(real);
|
currentKey=ByteString.wrap(real);
|
currentValue=value;
|
defined=true;
|
return true;
|
}
|
defined=false;
|
return false;
|
}
|
|
/**
|
* Bulk, not operation: with no condition to seek on, this is {@code order by k desc} over
|
* the whole table - and on mssql, where {@code k} is a {@code varbinary(max)} that cannot
|
* be an index key, a scan and a sort of it. It is also not on a search path: every open of
|
* a backend runs it once per base DN, through {@code EntryContainer.getHighestEntryID()},
|
* outside the try/catch of {@code BackendImpl.openBackend()} - a bound of two minutes here
|
* would turn a large backend that opens slowly into one that does not open at all.
|
*/
|
@Override
|
public boolean positionToLastKey() {
|
if (fetchBatch(null,null,0,true,1,StatementBound.BULK)) {
|
advanceFromBuffer();
|
return true;
|
}
|
defined=false;
|
return false;
|
}
|
|
/**
|
* The class of the cursor, unlike {@link #positionToLastKey()}, which is bulk however it
|
* was opened: an offset comes from the VLV request of a client, so this runs on a search
|
* path and has to give the worker thread back - an import has no VLV position to seek to.
|
* That a deep offset is served by walking to it - the engines have no other way to answer
|
* an {@code offset ?} - is what makes the bound reachable here, and reaching it answers the
|
* request with an error rather than parking a thread of the server on it.
|
*/
|
@Override
|
public boolean positionToIndex(int index) {
|
if (!buffer.isEmpty()) { // absolute jump: random access, back to small batches
|
nextBatchSize=initialBatchSize;
|
}
|
if (index>=0 && fetchBatch(null,null,index,false,adaptiveBatchSize(),batchBound)) {
|
advanceFromBuffer();
|
return true;
|
}
|
defined=false;
|
return false;
|
}
|
}
|
|
@Override
|
public Set<TreeName> listTrees() {
|
return tree2table.asMap().keySet();
|
}
|
|
final class ImporterImpl implements Importer {
|
final Connection con;
|
final ReadableTransactionImpl txr;
|
final WriteableTransactionTransactionImpl txw;
|
// The trees this import wrote: close() refreshes the statistics of these and only these,
|
// so rebuilding a single index does not gather statistics for the whole backend. A full
|
// import legitimately covers every tree - AbstractTwoPhaseImportStrategy.beforePhaseOne
|
// clears them all before the first record is written - including when the import is
|
// aborted, since close() runs from the try-with-resources of OnDiskMergeImporter.
|
final Set<TreeName> writtenTrees = ConcurrentHashMap.newKeySet();
|
|
// Set when the import failed or was cancelled. Its trees hold whatever the import got
|
// through before it stopped - beforePhaseOne cleared them all, so that can be nothing at
|
// all - and the operator is going to run it again, so there is nothing worth describing
|
// to the optimizer here: on oracle gathering those statistics is a full scan per table
|
// that would delay the report of a failure, or of a cancellation, by all of its duration.
|
volatile boolean aborted = false;
|
|
final Boolean isOpen;
|
|
/**
|
* Both transactions of an import take the bulk class, and with them every statement it
|
* issues: phase one writes the trees through {@code put()}, phase two reads them back
|
* through {@code read()} and walks them through {@code openCursor()}, and none of that has
|
* a client waiting on it. Bounding those as entry reads is not merely strict, it fails work
|
* that ran to the end before this bound existed: {@code h} is the primary key on every
|
* dialect and the default lock wait is forever on mssql, postgres and oracle, so an upsert
|
* of an online import blocked by an LDAP write on the same table sat until the bound of an
|
* entry read and then failed the import.
|
*/
|
public ImporterImpl() {
|
// The open belongs here with the borrow it precedes (#878): startImport() used to do both,
|
// and a failure between them had two owners to give back what each had taken.
|
isOpen=getStorageStatus().isWorking();
|
if (!isOpen) {
|
try {
|
open(AccessMode.READ_WRITE);
|
}catch (Exception e) {
|
throw new StorageRuntimeException(e);
|
}
|
}
|
// Nothing holds what this constructor takes until it returns: close() belongs to an
|
// object that was built, so a throw below would leave the connection borrowed and the
|
// storage this constructor opened open, with nobody left to give either back.
|
Connection borrowed=null;
|
try {
|
// An import writes by definition, so a storage that is not writeable refuses one where the
|
// importer is built - which is where it was refused until the write transaction of a read-only
|
// storage became one that is granted and checks per operation (#874). Left to that check, an
|
// import of such a storage would take a connection out of the pool, begin its transaction and
|
// fail at the first tree it clears rather than at its start.
|
// Inside the try and in front of the borrow: with the borrow moved in here (#878) the
|
// refusal now takes no connection at all, and the open above is still given back by the
|
// catch below - which is the half of it a storage that arrives closed and read-only needs.
|
if (!accessMode.isWriteable()) {
|
throw new ReadOnlyStorageException();
|
}
|
borrowed=getValidatedConnection();
|
txr =new ReadableTransactionImpl(borrowed, StatementBound.BULK);
|
txw =new WriteableTransactionTransactionImpl(borrowed, StatementBound.BULK);
|
con = borrowed;
|
borrowed=null;
|
}catch (Throwable e){
|
// Throwable rather than Exception, the way close() below catches it and for the same
|
// reason: the borrow is handed off to nothing until this constructor returns, and
|
// only its close() gives back the permit it took. new WriteableTransactionTransactionImpl
|
// runs a StampSession in a field initializer, so an Error out of a bulk import - an
|
// OutOfMemoryError is the one to expect - would leave the connection borrowed for the
|
// life of the server, and enough of them walk the bound of the pool down to nothing
|
// (issue #878).
|
if (borrowed!=null) {
|
try {
|
borrowed.close();
|
}catch (Throwable e2) {
|
// suppressed rather than dropped: the failure being unwound is the one the
|
// caller asked about, and a return that failed on top of it is worth reading
|
e.addSuppressed(e2);
|
}
|
}
|
if (!isOpen) {
|
JDBCStorage.this.close();
|
}
|
if (e instanceof Error) {
|
// on its way out as it is: an Error says the JVM is in no state to have this
|
// wrapped and reported as a failure of the storage
|
throw (Error) e;
|
}
|
throw e instanceof StorageRuntimeException ? (StorageRuntimeException) e : new StorageRuntimeException(e);
|
}
|
}
|
|
@Override
|
public void aborted() {
|
aborted = true;
|
}
|
|
/**
|
* Hands the connection back to the pool and closes the stamp session, whatever went before.
|
* Returns the failure the caller is to report: the return rolls back, and the rollback
|
* fails on exactly the connection whose commit just did, so the commit stays the exception
|
* the caller sees and this one rides along with it instead of replacing it.
|
*/
|
private SQLException releaseConnection(SQLException failure) {
|
try {
|
con.close();
|
} catch (Throwable e) {
|
// Throwable rather than SQLException: this close() is the return to the pool, whose
|
// rollback a driver is free to fail unchecked. Reported rather than thrown, since a
|
// throw out of here would leave with the failure the caller actually came for - the
|
// commit above, and in the Throwable branch of close() the Error that branch exists
|
// to preserve - dropped on the floor (issue #878).
|
final SQLException reported=e instanceof SQLException ? (SQLException) e
|
: new SQLException("the connection of the import could not be returned to the pool", e);
|
if (failure==null) {
|
failure=reported;
|
}else {
|
failure.addSuppressed(reported);
|
}
|
} finally {
|
txw.stampSession.close();
|
}
|
return failure;
|
}
|
|
// The connection goes back whatever the commit does, and the storage this importer opened
|
// is closed whatever the connection does: an importer is closed on the way out of a failed
|
// import as readily as a finished one - a clearTree() that reaches the bulk bound is one
|
// way there - and a commit that throws on the way would otherwise leave the connection
|
// out of the pool for good, holding the transaction and the locks of that import.
|
@Override
|
public void close() {
|
try {
|
SQLException failure=null;
|
try {
|
con.commit();
|
if (aborted) {
|
logger.debug(LocalizableMessage.raw("jdbc: import aborted: statistics of the trees it wrote are left alone"));
|
}else {
|
updateTableStatistics(con, writtenTrees);
|
}
|
} catch (SQLException e) {
|
failure=e;
|
} catch (Throwable t) {
|
// Back to the pool whatever came out of the commit, not only on the SQLException
|
// a driver is supposed to throw: nothing else holds this connection, and only
|
// its close() gives back the permit it took. A pool is never removed from the
|
// map, so a permit lost to an Error out of a bulk import - or to a driver
|
// failing unchecked - is lost for the life of the server, and enough of them
|
// walk the bound down to nothing (issue #878).
|
final SQLException onTheWayOut=releaseConnection(null);
|
if (onTheWayOut!=null) {
|
t.addSuppressed(onTheWayOut);
|
}
|
throw t;
|
}
|
// Back to the pool even when the commit failed: nothing else holds this connection,
|
// so leaving it behind would leak it along with the failure.
|
failure=releaseConnection(failure);
|
if (failure!=null) {
|
throw new StorageRuntimeException(failure);
|
}
|
} finally {
|
if (!isOpen) {
|
JDBCStorage.this.close();
|
}
|
}
|
}
|
|
@Override
|
public void clearTree(TreeName name) {
|
txw.clearTree(name);
|
writtenTrees.add(name);
|
}
|
|
@Override
|
public void put(TreeName treeName, ByteSequence key, ByteSequence value) {
|
txw.put(treeName, key, value);
|
writtenTrees.add(treeName);
|
}
|
|
@Override
|
public ByteString read(TreeName treeName, ByteSequence key) {
|
return txr.read(treeName, key);
|
}
|
|
// Bulk like every other statement of an import, by the class of the transaction it comes
|
// from: this walks a whole tree with no client waiting on it - phase one of a rebuild-index
|
// reads every record of id2entry through this cursor (OnDiskMergeImporter.ID2EntrySource) -
|
// and on mssql it walks it unindexed, so a batch of it is a scan and a sort of the table
|
// rather than a step along an index.
|
@Override
|
public SequentialCursor<ByteString, ByteString> openCursor(TreeName treeName) {
|
return txr.openCursor(treeName);
|
}
|
}
|
|
//import
|
@Override
|
public Importer startImport() throws ConfigException, StorageRuntimeException {
|
// Everything this used to do before building the importer - opening a closed storage, and
|
// borrowing the connection an import keeps for its whole duration - is the importer's own now
|
// (#878). Split between the two, a failure in between had to be given back by whichever of them
|
// had taken what, and the constructor's own throw was covered by neither.
|
return new ImporterImpl();
|
}
|
|
//backup
|
@Override
|
public boolean supportsBackupAndRestore() {
|
return true;
|
}
|
|
@Override
|
public void createBackup(BackupConfig backupConfig) throws DirectoryException
|
{
|
// TODO backup over snapshot or SQL export
|
//new BackupManager(config.getBackendId()).createBackup(this, backupConfig);
|
}
|
|
@Override
|
public void removeBackup(BackupDirectory backupDirectory, String backupID) throws DirectoryException
|
{
|
new BackupManager(config.getBackendId()).removeBackup(backupDirectory, backupID);
|
}
|
|
@Override
|
public void restoreBackup(RestoreConfig restoreConfig) throws DirectoryException
|
{
|
// TODO restore over snapshot or SQL export
|
//new BackupManager(config.getBackendId()).restoreBackup(this, restoreConfig);
|
}
|
|
}
|
