/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
|
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
|
* add the following below this CDDL HEADER, with the fields enclosed
|
* by brackets "[]" replaced with your own identifying information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2006-2010 Sun Microsystems, Inc.
|
*/
|
package org.opends.server.replication.server;
|
import org.opends.messages.MessageBuilder;
|
|
import static org.opends.server.loggers.ErrorLogger.logError;
|
import static org.opends.messages.ReplicationMessages.*;
|
import static org.opends.server.util.StaticUtils.stackTraceToSingleLineString;
|
|
import java.util.ArrayList;
|
import java.util.Date;
|
import java.util.List;
|
import java.util.LinkedList;
|
|
import org.opends.server.admin.std.server.MonitorProviderCfg;
|
import org.opends.server.api.DirectoryThread;
|
import org.opends.server.api.MonitorProvider;
|
import org.opends.server.config.ConfigException;
|
import org.opends.server.types.Attribute;
|
import org.opends.server.types.Attributes;
|
import org.opends.server.types.InitializationException;
|
import org.opends.server.util.TimeThread;
|
import org.opends.server.core.DirectoryServer;
|
import org.opends.server.replication.common.ChangeNumber;
|
import org.opends.server.replication.protocol.UpdateMsg;
|
import org.opends.server.replication.server.ReplicationDB.ReplServerDBCursor;
|
|
import com.sleepycat.je.DatabaseException;
|
import com.sleepycat.je.LockConflictException;
|
|
/**
|
* This class is used for managing the replicationServer database for each
|
* server in the topology.
|
* It is responsible for efficiently saving the updates that is received from
|
* each master server into stable storage.
|
* This class is also able to generate a ReplicationIterator that can be
|
* used to read all changes from a given ChangeNUmber.
|
*
|
* This class publish some monitoring information below cn=monitor.
|
*
|
*/
|
public class DbHandler implements Runnable
|
{
|
// The msgQueue holds all the updates not yet saved to stable storage.
|
// This list is only used as a temporary placeholder so that the write
|
// in the stable storage can be grouped for efficiency reason.
|
// Adding an update synchronously add the update to this list.
|
// A dedicated thread loops on flush() and trim().
|
// flush() : get a number of changes from the in memory list by block
|
// and write them to the db.
|
// trim() : deletes from the DB a number of changes that are older than a
|
// certain date.
|
//
|
// Changes are not read back by replicationServer threads that are responsible
|
// for pushing the changes to other replication server or to LDAP server
|
//
|
private final LinkedList<UpdateMsg> msgQueue =
|
new LinkedList<UpdateMsg>();
|
|
// The High and low water mark for the max size of the msgQueue.
|
// the threads calling add() method will be blocked if the size of
|
// msgQueue becomes larger than the queueHimark and will resume
|
// only when the size of the msgQueue goes below queueLowmark.
|
int queueMaxSize = 5000;
|
int queueLowmark = 1000;
|
int queueHimark = 4000;
|
|
// The queue himark and lowmark in bytes, this is set to 100 times the
|
// himark and lowmark in number of updates.
|
int queueMaxBytes = 100 * queueMaxSize;
|
int queueLowmarkBytes = 100 * queueLowmark;
|
int queueHimarkBytes = 100 * queueHimark;
|
|
// The number of bytes currently in the queue
|
int queueByteSize = 0;
|
|
private ReplicationDB db;
|
private ChangeNumber firstChange = null;
|
private ChangeNumber lastChange = null;
|
private int serverId;
|
private String baseDn;
|
private DbMonitorProvider dbMonitor = new DbMonitorProvider();
|
private boolean shutdown = false;
|
private boolean done = false;
|
private DirectoryThread thread = null;
|
private final Object flushLock = new Object();
|
private ReplicationServer replicationServer;
|
|
// The maximum number of retries in case of DatabaseDeadlock Exception.
|
private static final int DEADLOCK_RETRIES = 10;
|
|
private long latestTrimDate = 0;
|
|
/**
|
*
|
* The trim age in milliseconds. Changes record in the change DB that
|
* are older than this age are removed.
|
*
|
*/
|
private long trimage;
|
|
/**
|
* Creates a new dbHandler associated to a given LDAP server.
|
*
|
* @param id Identifier of the DB.
|
* @param baseDn the baseDn for which this DB was created.
|
* @param replicationServer The ReplicationServer that creates this dbHandler.
|
* @param dbenv the Database Env to use to create the ReplicationServer DB.
|
* server for this domain.
|
* @param queueSize The queueSize to use when creating the dbHandler.
|
* @throws DatabaseException If a database problem happened
|
*/
|
public DbHandler(
|
int id, String baseDn, ReplicationServer replicationServer,
|
ReplicationDbEnv dbenv, int queueSize)
|
throws DatabaseException
|
{
|
this.replicationServer = replicationServer;
|
serverId = id;
|
this.baseDn = baseDn;
|
trimage = replicationServer.getTrimage();
|
queueMaxSize = queueSize;
|
queueLowmark = queueSize * 1 / 5;
|
queueHimark = queueSize * 4 / 5;
|
queueMaxBytes = 200 * queueMaxSize;
|
queueLowmarkBytes = 200 * queueLowmark;
|
queueHimarkBytes = 200 * queueLowmark;
|
db = new ReplicationDB(id, baseDn, replicationServer, dbenv);
|
firstChange = db.readFirstChange();
|
lastChange = db.readLastChange();
|
thread = new DirectoryThread(this,
|
"Replication Server db for DS " + id + " and " + baseDn + " in RS " +
|
replicationServer.getServerId());
|
thread.start();
|
|
DirectoryServer.deregisterMonitorProvider(
|
dbMonitor.getMonitorInstanceName());
|
DirectoryServer.registerMonitorProvider(dbMonitor);
|
}
|
|
/**
|
* Add an update to the list of messages that must be saved to the db
|
* managed by this db handler.
|
* This method is blocking if the size of the list of message is larger
|
* than its maximum.
|
*
|
* @param update The update that must be saved to the db managed by this db
|
* handler.
|
*/
|
public void add(UpdateMsg update)
|
{
|
synchronized (msgQueue)
|
{
|
int size = msgQueue.size();
|
if ((size > queueHimark) || (queueByteSize > queueHimarkBytes))
|
msgQueue.notify();
|
|
while ((size > queueMaxSize) || (queueByteSize > queueMaxBytes))
|
{
|
try
|
{
|
msgQueue.wait(500);
|
} catch (InterruptedException e)
|
{
|
// simply loop to try again.
|
}
|
size = msgQueue.size();
|
}
|
|
queueByteSize += update.size();
|
msgQueue.add(update);
|
if (lastChange == null || lastChange.older(update.getChangeNumber()))
|
{
|
lastChange = update.getChangeNumber();
|
}
|
if (firstChange == null)
|
firstChange = update.getChangeNumber();
|
}
|
}
|
|
/**
|
* Get some changes out of the message queue of the LDAP server.
|
* (from the beginning of the queue)
|
* @param number the maximum number of messages to extract.
|
* @return a List containing number changes extracted from the queue.
|
*/
|
private List<UpdateMsg> getChanges(int number)
|
{
|
int current = 0;
|
LinkedList<UpdateMsg> changes = new LinkedList<UpdateMsg>();
|
|
synchronized (msgQueue)
|
{
|
int size = msgQueue.size();
|
while ((current < number) && (current < size))
|
{
|
UpdateMsg msg = msgQueue.get(current);
|
current++;
|
changes.add(msg);
|
}
|
}
|
return changes;
|
}
|
|
/**
|
* Get the firstChange.
|
* @return Returns the firstChange.
|
*/
|
public ChangeNumber getFirstChange()
|
{
|
return firstChange;
|
}
|
|
/**
|
* Get the lastChange.
|
* @return Returns the lastChange.
|
*/
|
public ChangeNumber getLastChange()
|
{
|
return lastChange;
|
}
|
|
/**
|
* Get the number of changes.
|
*
|
* @return Returns the number of changes.
|
*/
|
public long getChangesCount()
|
{
|
try
|
{
|
return lastChange.getSeqnum() - firstChange.getSeqnum() + 1;
|
}
|
catch (Exception e)
|
{
|
return 0;
|
}
|
}
|
|
/**
|
* Generate a new ReplicationIterator that allows to browse the db
|
* managed by this dbHandler and starting at the position defined
|
* by a given changeNumber.
|
*
|
* @param changeNumber The position where the iterator must start.
|
*
|
* @return a new ReplicationIterator that allows to browse the db
|
* managed by this dbHandler and starting at the position defined
|
* by a given changeNumber.
|
*
|
* @throws DatabaseException if a database problem happened.
|
* @throws Exception If there is no other change to push after change
|
* with changeNumber number.
|
*/
|
public ReplicationIterator generateIterator(ChangeNumber changeNumber)
|
throws DatabaseException, Exception
|
{
|
if (changeNumber == null)
|
{
|
flush();
|
}
|
ReplicationIterator it =
|
new ReplicationIterator(serverId, db, changeNumber, this);
|
return it;
|
}
|
|
/**
|
* Return the number of changes between 2 provided change numbers.
|
* @param from The lower (older) change number.
|
* @param to The upper (newer) change number.
|
* @return The computed number of changes.
|
*/
|
public int traverseAndCount(ChangeNumber from, ChangeNumber to)
|
{
|
int count = 0;
|
flush();
|
ReplServerDBCursor cursor = null;
|
try
|
{
|
try
|
{
|
cursor = db.openReadCursor(from);
|
}
|
catch(Exception e)
|
{
|
return 0;
|
}
|
ChangeNumber curr = null;
|
while ((curr = cursor.nextChangeNumber())!=null)
|
{
|
if (curr.newerOrEquals(to))
|
break;
|
count++;
|
}
|
}
|
finally
|
{
|
if (cursor != null)
|
cursor.abort();
|
}
|
return count;
|
}
|
|
/**
|
* Removes the provided number of messages from the beginning of the msgQueue.
|
*
|
* @param number the number of changes to be removed.
|
*/
|
private void clearQueue(int number)
|
{
|
synchronized (msgQueue)
|
{
|
int current = 0;
|
while ((current < number) && (!msgQueue.isEmpty()))
|
{
|
UpdateMsg msg = msgQueue.remove(); // remove first
|
queueByteSize -= msg.size();
|
current++;
|
}
|
if ((msgQueue.size() < queueLowmark) &&
|
(queueByteSize < queueLowmarkBytes))
|
msgQueue.notifyAll();
|
}
|
}
|
|
/**
|
* Shutdown this dbHandler.
|
*/
|
public void shutdown()
|
{
|
if (shutdown == true)
|
{
|
return;
|
}
|
|
shutdown = true;
|
synchronized (msgQueue)
|
{
|
msgQueue.notifyAll();
|
}
|
|
synchronized (this)
|
{
|
while (done == false)
|
{
|
try
|
{
|
this.wait();
|
} catch (Exception e)
|
{}
|
}
|
}
|
|
while (msgQueue.size() != 0)
|
flush();
|
|
db.shutdown();
|
DirectoryServer.deregisterMonitorProvider(
|
dbMonitor.getMonitorInstanceName());
|
}
|
|
/**
|
* Run method for this class.
|
* Periodically Flushes the ReplicationServerDomain cache from memory to the
|
* stable storage and trims the old updates.
|
*/
|
public void run()
|
{
|
while (shutdown == false)
|
{
|
try
|
{
|
flush();
|
trim();
|
|
synchronized (msgQueue)
|
{
|
if ((msgQueue.size() < queueLowmark) &&
|
(queueByteSize < queueLowmarkBytes))
|
{
|
try
|
{
|
msgQueue.wait(1000);
|
} catch (InterruptedException e)
|
{ }
|
}
|
}
|
} catch (Exception end)
|
{
|
MessageBuilder mb = new MessageBuilder();
|
mb.append(ERR_EXCEPTION_CHANGELOG_TRIM_FLUSH.get());
|
mb.append(stackTraceToSingleLineString(end));
|
logError(mb.toMessage());
|
synchronized (this)
|
{
|
// set the done variable to true so that this thread don't
|
// get stuck in this dbHandler.shutdown() when it get called
|
// by replicationServer.shutdown();
|
done = true;
|
}
|
if (replicationServer != null)
|
replicationServer.shutdown();
|
break;
|
}
|
}
|
// call flush a last time before exiting to make sure that
|
// no change was forgotten in the msgQueue
|
flush();
|
|
synchronized (this)
|
{
|
done = true;
|
this.notifyAll();
|
}
|
}
|
|
/**
|
* Retrieves the latest trim date.
|
* @return the latest trim date.
|
*/
|
public long getLatestTrimDate()
|
{
|
return latestTrimDate;
|
}
|
|
|
/**
|
* Trim old changes from this replicationServer database.
|
* @throws DatabaseException In case of database problem.
|
*/
|
private void trim() throws DatabaseException, Exception
|
{
|
if (trimage == 0)
|
return;
|
int size = 0;
|
boolean finished = false;
|
boolean done = false;
|
|
latestTrimDate = TimeThread.getTime() - trimage;
|
|
ChangeNumber trimDate = new ChangeNumber(latestTrimDate, 0, 0);
|
|
// In case of deadlock detection by the Database, this thread can
|
// by aborted by a DeadlockException. This is a transient error and
|
// the transaction should be attempted again.
|
// We will try DEADLOCK_RETRIES times before failing.
|
int tries = 0;
|
while ((tries++ < DEADLOCK_RETRIES) && (!done))
|
{
|
synchronized (flushLock)
|
{
|
/* the trim is done by group in order to save some CPU and IO bandwidth
|
* start the transaction then do a bunch of remove then commit
|
*/
|
ReplServerDBCursor cursor;
|
cursor = db.openDeleteCursor();
|
|
try
|
{
|
while ((size < 5000 ) && (!finished))
|
{
|
ChangeNumber changeNumber = cursor.nextChangeNumber();
|
if (changeNumber != null)
|
{
|
if ((!changeNumber.equals(lastChange))
|
&& (changeNumber.older(trimDate)))
|
{
|
size++;
|
cursor.delete();
|
}
|
else
|
{
|
firstChange = changeNumber;
|
finished = true;
|
}
|
}
|
else
|
finished = true;
|
}
|
cursor.close();
|
done = true;
|
}
|
catch (LockConflictException e)
|
{
|
cursor.abort();
|
if (tries == DEADLOCK_RETRIES)
|
{
|
// could not handle the Deadlock after DEADLOCK_RETRIES tries.
|
// shutdown the ReplicationServer.
|
shutdown = true;
|
throw (e);
|
}
|
}
|
catch (DatabaseException e)
|
{
|
// mark shutdown for this db so that we don't try again to
|
// stop it from cursor.close() or methods called by cursor.close()
|
shutdown = true;
|
cursor.abort();
|
throw (e);
|
}
|
}
|
}
|
}
|
|
/**
|
* Flush a number of updates from the memory list to the stable storage.
|
* Flush is done by chunk sized to 500 messages, starting from the
|
* beginning of the list.
|
*/
|
public void flush()
|
{
|
int size;
|
int chunksize = (500 < queueMaxSize ? 500 : queueMaxSize);
|
|
do
|
{
|
synchronized(flushLock)
|
{
|
// get N (or less) messages from the queue to save to the DB
|
// (from the beginning of the queue)
|
List<UpdateMsg> changes = getChanges(chunksize);
|
|
// if no more changes to save exit immediately.
|
if ((changes == null) || ((size = changes.size()) == 0))
|
return;
|
|
// save the change to the stable storage.
|
db.addEntries(changes);
|
|
// remove the changes from the list of changes to be saved
|
// (remove from the beginning of the queue)
|
clearQueue(changes.size());
|
}
|
} while (size >= chunksize);
|
}
|
|
/**
|
* This internal class is used to implement the Monitoring capabilities
|
* of the dbHandler.
|
*/
|
private class DbMonitorProvider extends MonitorProvider<MonitorProviderCfg>
|
{
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public ArrayList<Attribute> getMonitorData()
|
{
|
ArrayList<Attribute> attributes = new ArrayList<Attribute>();
|
attributes.add(Attributes.create("replicationServer-database",
|
String.valueOf(serverId)));
|
attributes.add(Attributes.create("domain-name", baseDn.toString()));
|
if (firstChange != null)
|
{
|
Date firstTime = new Date(firstChange.getTime());
|
attributes.add(Attributes.create("first-change", firstChange
|
.toString()
|
+ " " + firstTime.toString()));
|
}
|
if (lastChange != null)
|
{
|
Date lastTime = new Date(lastChange.getTime());
|
attributes.add(Attributes.create("last-change", lastChange
|
.toString()
|
+ " " + lastTime.toString()));
|
}
|
attributes.add(
|
Attributes.create("queue-size", String.valueOf(msgQueue.size())));
|
attributes.add(
|
Attributes.create("queue-size-bytes", String.valueOf(queueByteSize)));
|
|
return attributes;
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public String getMonitorInstanceName()
|
{
|
ReplicationServerDomain domain =
|
replicationServer.getReplicationServerDomain(baseDn, false);
|
|
return "ReplicationServer database " + String.valueOf(serverId) +
|
",cn=" + domain.getMonitorInstanceName();
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public void initializeMonitorProvider(MonitorProviderCfg configuration)
|
throws ConfigException,InitializationException
|
{
|
// Nothing to do for now
|
}
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public String toString()
|
{
|
return(baseDn + " " + serverId + " " + firstChange + " " + lastChange);
|
}
|
|
/**
|
* Set the Purge delay for this db Handler.
|
* @param delay The purge delay in Milliseconds.
|
*/
|
public void setPurgeDelay(long delay)
|
{
|
trimage = delay;
|
}
|
|
/**
|
* Clear the changes from this DB (from both memory cache and DB storage).
|
* @throws DatabaseException When an exception occurs while removing the
|
* changes from the DB.
|
* @throws Exception When an exception occurs while accessing a resource
|
* from the DB.
|
*
|
*/
|
public void clear() throws DatabaseException, Exception
|
{
|
synchronized(flushLock)
|
{
|
msgQueue.clear();
|
queueByteSize = 0;
|
|
db.clear();
|
firstChange = db.readFirstChange();
|
lastChange = db.readLastChange();
|
}
|
}
|
|
/**
|
* Getter fot the serverID of the server for which this database is managed.
|
*
|
* @return the serverId.
|
*/
|
public int getServerId()
|
{
|
return this.serverId;
|
}
|
|
/**
|
* Return the size of the msgQueue (the memory cache of the DbHandler).
|
* For test purpose.
|
* @return The memory queue size.
|
*/
|
public int getQueueSize()
|
{
|
return this.msgQueue.size();
|
}
|
|
/**
|
* Set the counter writing window size (public for unit tests only).
|
* @param size Size in number of record.
|
*/
|
public void setCounterWindowSize(int size)
|
{
|
db.setCounterWindowSize(size);
|
}
|
|
/**
|
* Return the number of changes between 2 provided change numbers.
|
* This a alternative to traverseAndCount, expected to be much more efficient
|
* when there is a huge number of changes in the Db.
|
* @param from The lower (older) change number.
|
* @param to The upper (newer) change number.
|
* @return The computed number of changes.
|
*/
|
public int getCount(ChangeNumber from, ChangeNumber to)
|
{
|
int c=0;
|
flush();
|
c = db.count(from, to);
|
return c;
|
}
|
|
}
|
