* The import of a total update streams over the session of the domain, on its listener * thread, and the backend it replaces is deregistered for the length of it. A change which * was queued for replay before the {@code InitializeTargetMsg} arrived is replayed into no * backend: whatever such a replay decides is about to be overwritten by the import, and the * one thing it must not do is stop the session the import is reading (issue #956). The same * holds from the moment the total update is asked for: the answer to the request arrives * over that session, so a replay which fails while it is on its way must not restart it. *
* The exporter is a broker of this test, so that the test says when the entries arrive: the
* change is replayed while the import is waiting for them - or, for the request, while the
* exporter is holding the answer.
*/
@SuppressWarnings("javadoc")
public class ReplayDuringImportTest extends ReplicationTestCase
{
/**
* The memory backend of {@code o=test} loses its data when it is disabled and enabled
* back, which is what an import does to the backend it replaces: a total update needs a
* backend which keeps what was imported into it.
*/
private static final String EXAMPLE_DN = "dc=example,dc=com";
private static final int RS_ID = 611;
private static final int DS_ID = 1;
private static final int EXPORTER_ID = 2;
private static final int INIT_WINDOW = 100;
private static final AtomicBoolean SHUTDOWN = new AtomicBoolean(false);
/** An entry of the exporter's data, and its entryUUID. */
private static final String IMPORTED_ENTRY_DN = "cn=imported,ou=People," + EXAMPLE_DN;
private static final String IMPORTED_ENTRY_UUID = "21111111-1111-1111-1111-111111111113";
private DN baseDN;
private ReplicationServer replicationServer;
private LDAPReplicationDomain domain;
private TestSynchronousReplayQueue queue;
private ReplicationBroker exporter;
private CSNGenerator gen;
@BeforeMethod
public void setUpLocal() throws Exception
{
baseDN = DN.valueOf(EXAMPLE_DN);
TestCaseUtils.clearBackend("userRoot", EXAMPLE_DN);
final int rsPort = TestCaseUtils.findFreePort();
replicationServer = new ReplicationServer(new ReplServerFakeConfiguration(
rsPort, "replayDuringImportTestDb", 0, RS_ID, 0, 100, new TreeSet
* The change is given back at the top of its first attempt: the data it would be applied
* to is being replaced, so nothing is attempted into the backend the import took away,
* nothing is reported, and the session is left to the import - which streams every entry
* to its end. Without the hold-off the operation is refused with NO_SUCH_OBJECT - nothing
* serves the base DN - and the entryUUID search conflict resolution reads the data with
* can not run either: the attempts in place are spent into no backend and the exit
* reports the change; without the owner the total update is, the session is then
* restarted for the change to be delivered again, which stops the broker the import is
* reading, and the import ends on the entries which had arrived with nothing to say it.
*/
@Test(timeOut = 120_000)
public void aReplayDuringTheImportLeavesTheSessionToTheImport() throws Exception
{
final Entry entry = TestCaseUtils.addEntry(
"dn: cn=renamedSince," + EXAMPLE_DN,
"objectClass: top",
"objectClass: person",
"cn: renamedSince",
"sn: renamedSince");
final String entryUUID = getEntryUUID(entry.getName());
final String[] exported = exportedEntries();
startImportInto(exported.length);
// Queued before the InitializeTargetMsg arrived, replayed into no backend.
final CSN csn = gen.newCSN();
replayMsg(new ModifyMsg(csn, DN.valueOf("cn=movedAway," + EXAMPLE_DN),
generatemods("description", "replayed during the import"), entryUUID));
finishImport(exported);
for (String ldif : exported)
{
final DN dn = dnOf(ldif);
assertTrue(entryExists(dn), "the import ended before " + dn
+ " arrived: the session it streams over was stopped from under it");
}
/*
* The two roads which leave the session to the import are told apart here: the
* hold-off gives the change back before an attempt is made, the guard on the restart
* after the attempts are spent. The exhaustion exit is the one thing the first road
* leaves no record of.
*/
assertThat(errorLogRecordsOf(ERR_ERROR_REPLAYING_OPERATION.ordinal(), csn))
.as("the change was attempted into no backend instead of being given back at once")
.isEmpty();
assertThat(errorLogRecordsOf(WARN_REPLAY_RETRYING_CHANGE.ordinal(), csn))
.as("the change was asked for again, which restarts the session the import streams over")
.isEmpty();
}
/**
* A change given back while the import ran must not hold the ServerState back once the
* import has replaced the data.
*
* A change which is given back stays listed as pending and uncommitted - that is what
* has the replication server send it again - and a commit advances the ServerState no
* further than the oldest uncommitted change. The state the import loads is the
* exporter's, which covers the change already, so nothing sends it again: left listed,
* it would stop the ServerState of this replica for good.
*/
@Test(timeOut = 120_000)
public void aChangeGivenBackDuringTheImportDoesNotHoldTheServerStateBack() throws Exception
{
final Entry entry = TestCaseUtils.addEntry(
"dn: cn=renamedSince," + EXAMPLE_DN,
"objectClass: top",
"objectClass: person",
"cn: renamedSince",
"sn: renamedSince");
final String entryUUID = getEntryUUID(entry.getName());
final String[] exported = exportedEntries();
startImportInto(exported.length);
replayMsg(new ModifyMsg(gen.newCSN(), DN.valueOf("cn=movedAway," + EXAMPLE_DN),
generatemods("description", "replayed during the import"), entryUUID));
finishImport(exported);
// A change on an entry the import brought, replayed once the import is over.
final DN importedDN = DN.valueOf(IMPORTED_ENTRY_DN);
final CSN csn = gen.newCSN();
replayMsg(new ModifyMsg(csn, importedDN,
generatemods("description", "replayed after the import"), IMPORTED_ENTRY_UUID));
assertThat(DirectoryServer.getEntry(importedDN).getAllAttributes("description"))
.as("a change replayed after the import was not applied").isNotEmpty();
assertTrue(domain.getServerState().cover(csn), "a change applied after the import was not"
+ " recorded: the change given back during the import is still listed and holds the"
+ " ServerState back");
}
/**
* A total update this replica asked for owns the session from the request, not from the
* first entry: the {@code InitializeTargetMsg} which answers the request arrives over
* that session, and a restart made while the answer is on its way loses it.
*
* The backend is live for the length of the request - nothing has been taken away yet -
* so the change is attempted, every attempt ends on an entryUUID search which does not
* run, and the exhaustion exit reports it: what is refused is the restart which would
* have followed, and the retry warning which goes with it. The exporter then answers the
* request, and its entries stream to their end over the session which was left alone.
*/
@Test(timeOut = 120_000)
public void aRequestOnItsWayOwnsTheSessionTheAnswerArrivesOver() throws Exception
{
final Entry entry = TestCaseUtils.addEntry(
"dn: cn=renamedSince," + EXAMPLE_DN,
"objectClass: top",
"objectClass: person",
"cn: renamedSince",
"sn: renamedSince");
final String entryUUID = getEntryUUID(entry.getName());
final String[] exported = exportedEntries();
// The request is out, and the exporter holds it until the change below has been replayed.
domain.initializeFromRemote(EXPORTER_ID, null);
assertNotNull(waitForSpecificMsg(exporter, InitializeRequestMsg.class));
final CSN csn = gen.newCSN();
ShortCircuitPlugin.registerShortCircuit(
OperationType.SEARCH, "PreParse", ResultCode.UNAVAILABLE.intValue());
try
{
replayMsg(new ModifyMsg(csn, DN.valueOf("cn=movedAway," + EXAMPLE_DN),
generatemods("description", "replayed while the request was on its way"), entryUUID));
assertTrue(ShortCircuitPlugin.getShortCircuitCount(OperationType.SEARCH, "PreParse")
>= LDAPReplicationDomain.IN_PLACE_REPLAY_ATTEMPTS,
"every attempt in place must have made its search: the backend is live while the"
+ " request is on its way, so nothing holds the replay off");
}
finally
{
ShortCircuitPlugin.deregisterShortCircuit(OperationType.SEARCH, "PreParse");
}
assertThat(errorLogRecordsOf(ERR_ERROR_REPLAYING_OPERATION.ordinal(), csn))
.as("the attempts in place were spent, which the exhaustion exit reports").isNotEmpty();
assertThat(errorLogRecordsOf(WARN_REPLAY_RETRYING_CHANGE.ordinal(), csn))
.as("the change was asked for again, which restarts the session the answer to the"
+ " request arrives over")
.isEmpty();
assertTrue(domain.isConnected(), "the session the request was made over was stopped");
answerImportRequest(exported.length);
finishImport(exported);
for (String ldif : exported)
{
final DN dn = dnOf(ldif);
assertTrue(entryExists(dn), "the import ended before " + dn
+ " arrived: the answer to the request was lost with the session it was made over");
}
}
/**
* Has the exporter start a total update into this replica, and returns once the backend
* of the domain is deregistered for it: from then on the import is reading the session,
* and a change replayed here is replayed into no backend.
*/
private void startImportInto(int entryCount) throws Exception
{
exporter.publish(new InitializeTargetMsg(
baseDN, EXPORTER_ID, DS_ID, EXPORTER_ID, entryCount, INIT_WINDOW));
final long deadline = System.currentTimeMillis() + 30_000;
while (getServerContext().getBackendConfigManager().findLocalBackendForEntry(baseDN) != null)
{
assertTrue(System.currentTimeMillis() < deadline,
"the import did not deregister the backend of the domain");
Thread.sleep(20);
}
}
/**
* Has the exporter answer the total update this replica asked for: the requestor of the
* {@code InitializeTargetMsg} is this replica, so the import runs in the context the
* request acquired.
*/
private void answerImportRequest(int entryCount) throws Exception
{
exporter.publish(new InitializeTargetMsg(
baseDN, EXPORTER_ID, DS_ID, DS_ID, entryCount, INIT_WINDOW));
}
/** Has the exporter send the entries of the total update, and waits for the import to end. */
private void finishImport(String... ldifEntries) throws Exception
{
int msgId = 0;
for (String ldif : ldifEntries)
{
exporter.publish(new EntryMsg(EXPORTER_ID, DS_ID, ldif.getBytes(UTF_8), ++msgId));
}
exporter.publish(new DoneMsg(EXPORTER_ID, DS_ID));
final long deadline = System.currentTimeMillis() + 60_000;
while (domain.ieRunning())
{
assertTrue(System.currentTimeMillis() < deadline, "the import did not end");
Thread.sleep(50);
}
}
/** The data of the exporter: the base entry and two entries below it. */
private static String[] exportedEntries()
{
return new String[] {
"dn: " + EXAMPLE_DN + "\n"
+ "objectClass: top\n"
+ "objectClass: domain\n"
+ "dc: example\n"
+ "entryUUID: 21111111-1111-1111-1111-111111111111\n"
+ "\n",
"dn: ou=People," + EXAMPLE_DN + "\n"
+ "objectClass: top\n"
+ "objectClass: organizationalUnit\n"
+ "ou: People\n"
+ "entryUUID: 21111111-1111-1111-1111-111111111112\n"
+ "\n",
"dn: " + IMPORTED_ENTRY_DN + "\n"
+ "objectClass: top\n"
+ "objectClass: person\n"
+ "cn: imported\n"
+ "sn: imported\n"
+ "entryUUID: " + IMPORTED_ENTRY_UUID + "\n"
+ "\n",
};
}
private static DN dnOf(String ldif)
{
return DN.valueOf(ldif.substring("dn: ".length(), ldif.indexOf('\n')));
}
/** The records of the error log which carry the provided message id and the provided CSN. */
private static List