/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE
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* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Portions Copyright 2006-2007 Sun Microsystems, Inc.
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*/
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package org.opends.server.replication.server;
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import static org.opends.server.loggers.ErrorLogger.logError;
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import static org.opends.server.messages.MessageHandler.getMessage;
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import static org.opends.server.messages.ReplicationMessages.*;
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import static org.opends.server.util.StaticUtils.stackTraceToSingleLineString;
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import java.io.IOException;
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import java.util.ArrayList;
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import java.util.LinkedHashSet;
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import java.util.List;
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import java.util.Map;
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import java.util.Set;
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import java.util.concurrent.ConcurrentHashMap;
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import org.opends.server.replication.common.ChangeNumber;
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import org.opends.server.replication.common.ServerState;
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import org.opends.server.replication.protocol.AckMessage;
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import org.opends.server.replication.protocol.ErrorMessage;
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import org.opends.server.replication.protocol.RoutableMessage;
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import org.opends.server.replication.protocol.UpdateMessage;
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import org.opends.server.replication.protocol.ReplServerInfoMessage;
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import org.opends.server.types.DN;
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import org.opends.server.types.ErrorLogCategory;
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import org.opends.server.types.ErrorLogSeverity;
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import com.sleepycat.je.DatabaseException;
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/**
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* This class define an in-memory cache that will be used to store
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* the messages that have been received from an LDAP server or
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* from another replication server and that should be forwarded to
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* other servers.
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*
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* The size of the cache is set by configuration.
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* If the cache becomes bigger than the configured size, the older messages
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* are removed and should they be needed again must be read from the backing
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* file
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*
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*
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* it runs a thread that is responsible for saving the messages
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* received to the disk and for trimming them
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* Decision to trim can be based on disk space or age of the message
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*/
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public class ReplicationCache
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{
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private Object flowControlLock = new Object();
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private DN baseDn = null;
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/*
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* The following map contains one balanced tree for each replica ID
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* to which we are currently publishing
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* the first update in the balanced tree is the next change that we
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* must push to this particular server
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*
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* We add new TreeSet in the HashMap when a new server register
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* to this replication server.
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*
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*/
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private Map<Short, ServerHandler> connectedServers =
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new ConcurrentHashMap<Short, ServerHandler>();
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/*
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* This map contains one ServerHandler for each replication servers
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* with which we are connected (so normally all the replication servers)
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* the first update in the balanced tree is the next change that we
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* must push to this particular server
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*
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* We add new TreeSet in the HashMap when a new replication server register
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* to this replication server.
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*/
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private Map<Short, ServerHandler> replicationServers =
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new ConcurrentHashMap<Short, ServerHandler>();
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/*
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* This map contains the List of updates received from each
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* LDAP server
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*/
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private Map<Short, DbHandler> sourceDbHandlers =
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new ConcurrentHashMap<Short, DbHandler>();
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private ReplicationServer replicationServer;
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/**
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* Creates a new ReplicationCache associated to the DN baseDn.
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*
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* @param baseDn The baseDn associated to the ReplicationCache.
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* @param replicationServer the ReplicationServer that created this
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* replicationServer cache.
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*/
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public ReplicationCache(DN baseDn, ReplicationServer replicationServer)
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{
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this.baseDn = baseDn;
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this.replicationServer = replicationServer;
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}
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/**
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* Add an update that has been received to the list of
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* updates that must be forwarded to all other servers.
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*
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* @param update The update that has been received.
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* @param sourceHandler The ServerHandler for the server from which the
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* update was received
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* @throws IOException When an IO exception happens during the update
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* processing.
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*/
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public void put(UpdateMessage update, ServerHandler sourceHandler)
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throws IOException
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{
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/*
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* TODO : In case that the source server is a LDAP server this method
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* should check that change did get pushed to at least one
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* other replication server before pushing it to the LDAP servers
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*/
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sourceHandler.updateServerState(update);
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sourceHandler.incrementInCount();
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if (update.isAssured())
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{
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int count = this.NumServers();
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if (count > 1)
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{
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if (sourceHandler.isReplicationServer())
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ServerHandler.addWaitingAck(update, sourceHandler.getServerId(),
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this, count - 1);
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else
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sourceHandler.addWaitingAck(update, count - 1);
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}
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else
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{
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sourceHandler.sendAck(update.getChangeNumber());
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}
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}
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// look for the dbHandler that is responsible for the master server which
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// generated the change.
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DbHandler dbHandler = null;
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synchronized (sourceDbHandlers)
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{
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short id = update.getChangeNumber().getServerId();
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dbHandler = sourceDbHandlers.get(id);
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if (dbHandler == null)
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{
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try
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{
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dbHandler = replicationServer.newDbHandler(id, baseDn);
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} catch (DatabaseException e)
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{
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/*
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* Because of database problem we can't save any more changes
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* from at least one LDAP server.
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* This replicationServer therefore can't do it's job properly anymore
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* and needs to close all its connections and shutdown itself.
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*/
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int msgID = MSGID_CHANGELOG_SHUTDOWN_DATABASE_ERROR;
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String message = getMessage(msgID) + stackTraceToSingleLineString(e);
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logError(ErrorLogCategory.SYNCHRONIZATION,
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ErrorLogSeverity.SEVERE_ERROR,
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message, msgID);
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replicationServer.shutdown();
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return;
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}
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sourceDbHandlers.put(id, dbHandler);
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}
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}
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// Publish the messages to the source handler
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dbHandler.add(update);
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/*
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* Push the message to the replication servers
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*/
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if (!sourceHandler.isReplicationServer())
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{
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for (ServerHandler handler : replicationServers.values())
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{
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handler.add(update, sourceHandler);
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}
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}
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/*
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* Push the message to the LDAP servers
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*/
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for (ServerHandler handler : connectedServers.values())
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{
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// don't forward the change to the server that just sent it
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if (handler == sourceHandler)
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{
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continue;
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}
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handler.add(update, sourceHandler);
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}
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}
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/**
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* Create initialize context necessary for finding the changes
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* that must be sent to a given LDAP or replication server.
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*
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* @param handler handler for the server that must be started
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* @throws Exception when method has failed
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* @return A boolean indicating if the start was successfull.
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*/
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public boolean startServer(ServerHandler handler) throws Exception
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{
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/*
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* create the balanced tree that will be used to forward changes
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*/
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synchronized (connectedServers)
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{
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ServerHandler oldHandler = connectedServers.get(handler.getServerId());
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if (connectedServers.containsKey(handler.getServerId()))
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{
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// looks like two LDAP servers have the same serverId
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// log an error message and drop this connection.
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int msgID = MSGID_DUPLICATE_SERVER_ID;
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String message = getMessage(msgID, oldHandler.toString(),
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handler.toString(), handler.getServerId());
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logError(ErrorLogCategory.SYNCHRONIZATION,
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ErrorLogSeverity.SEVERE_ERROR,
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message, msgID);
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return false;
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}
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connectedServers.put(handler.getServerId(), handler);
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// Update the remote replication servers with our list
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// of connected LDAP servers
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sendReplServerInfo();
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return true;
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}
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}
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/**
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* Stop operations with a given server.
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*
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* @param handler the server for which we want to stop operations
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*/
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public void stopServer(ServerHandler handler)
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{
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handler.stopHandler();
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if (handler.isReplicationServer())
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replicationServers.remove(handler.getServerId());
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else
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{
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connectedServers.remove(handler.getServerId());
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// Update the remote replication servers with our list
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// of connected LDAP servers
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sendReplServerInfo();
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}
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}
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/**
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* Create initialize context necessary for finding the changes
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* that must be sent to a given replication server.
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*
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* @param handler the server ID to which we want to forward changes
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* @throws Exception in case of errors
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* @return A boolean indicating if the start was successfull.
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*/
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public boolean startReplicationServer(ServerHandler handler) throws Exception
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{
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/*
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* create the balanced tree that will be used to forward changes
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*/
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synchronized (replicationServers)
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{
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ServerHandler oldHandler = replicationServers.get(handler.getServerId());
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if ((oldHandler != null))
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{
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if (oldHandler.getServerAddressURL().equals(
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handler.getServerAddressURL()))
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{
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// this is the same server, this means that our ServerStart messages
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// have been sent at about the same time and 2 connections
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// have been established.
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// Silently drop this connection.
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}
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else
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{
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// looks like two replication servers have the same serverId
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// log an error message and drop this connection.
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int msgID = MSGID_DUPLICATE_REPLICATION_SERVER_ID;
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String message = getMessage(msgID, oldHandler.getServerAddressURL(),
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handler.getServerAddressURL(), handler.getServerId());
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logError(ErrorLogCategory.SYNCHRONIZATION,
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ErrorLogSeverity.SEVERE_ERROR,
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message, msgID);
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}
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return false;
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}
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replicationServers.put(handler.getServerId(), handler);
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// Update this server with the list of LDAP servers
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// already connected
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handler.sendInfo(
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new ReplServerInfoMessage(getConnectedLDAPservers()));
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return true;
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}
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}
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/**
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* Get the next update that need to be sent to a given LDAP server.
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* This call is blocking when no update is available or when dependencies
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* do not allow to send the next available change
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*
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* @param handler The server handler for the target directory server.
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*
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* @return the update that must be forwarded
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*/
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public UpdateMessage take(ServerHandler handler)
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{
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UpdateMessage msg;
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/*
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* Get the balanced tree that we use to sort the changes to be
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* sent to the replica from the cookie
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*
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* The next change to send is always the first one in the tree
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* So this methods simply need to check that dependencies are OK
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* and update this replicaId RUV
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*
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* TODO : dependency :
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* before forwarding change, we should check that the dependency
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* that is indicated in this change is OK (change already in the RUV)
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*/
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msg = handler.take();
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synchronized (flowControlLock)
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{
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if (handler.restartAfterSaturation(null))
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flowControlLock.notifyAll();
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}
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return msg;
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}
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/**
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* Return a Set of String containing the lists of Replication servers
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* connected to this server.
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* @return the set of connected servers
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*/
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public Set<String> getChangelogs()
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{
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LinkedHashSet<String> mySet = new LinkedHashSet<String>();
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for (ServerHandler handler : replicationServers.values())
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{
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mySet.add(handler.getServerAddressURL());
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}
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return mySet;
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}
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/**
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* Return a Set containing the servers known by this replicationServer.
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* @return a set containing the servers known by this replicationServer.
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*/
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public Set<Short> getServers()
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{
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return sourceDbHandlers.keySet();
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}
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/**
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* Returns as a set of String the list of LDAP servers connected to us.
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* Each string is the serverID of a connected LDAP server.
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*
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* @return The set of connected LDAP servers
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*/
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public List<String> getConnectedLDAPservers()
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{
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List<String> mySet = new ArrayList<String>(0);
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for (ServerHandler handler : connectedServers.values())
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{
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mySet.add(String.valueOf(handler.getServerId()));
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}
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return mySet;
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}
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/**
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* Creates and returns an iterator.
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*
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* @param serverId Identifier of the server for which the iterator is created.
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* @param changeNumber Starting point for the iterator.
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* @return the created ReplicationIterator.
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*/
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public ReplicationIterator getChangelogIterator(short serverId,
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ChangeNumber changeNumber)
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{
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DbHandler handler = sourceDbHandlers.get(serverId);
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if (handler == null)
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return null;
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try
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{
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return handler.generateIterator(changeNumber);
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}
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catch (Exception e) {
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return null;
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}
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}
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/**
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* Get the baseDn.
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* @return Returns the baseDn.
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*/
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public DN getBaseDn()
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{
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return baseDn;
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}
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/**
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* creates a new ReplicationDB with specified identifier.
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* @param id the identifier of the new ReplicationDB.
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* @param db the new db.
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*
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* @throws DatabaseException If a database error happened.
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*/
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public void newDb(short id, DbHandler db) throws DatabaseException
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{
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synchronized (sourceDbHandlers)
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{
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sourceDbHandlers.put(id , db);
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}
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}
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/**
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* Get the number of currently connected servers.
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*
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* @return the number of currently connected servers.
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*/
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private int NumServers()
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{
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return replicationServers.size() + connectedServers.size();
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}
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/**
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* Add an ack to the list of ack received for a given change.
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*
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* @param message The ack message received.
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* @param fromServerId The identifier of the server that sent the ack.
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*/
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public void ack(AckMessage message, short fromServerId)
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{
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/*
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* there are 2 possible cases here :
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* - the message that was acked comes from a server to which
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* we are directly connected.
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* In this case, we can find the handler from the connectedServers map
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* - the message that was acked comes from a server to which we are not
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* connected.
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* In this case we need to find the replication server that forwarded
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* the change and send back the ack to this server.
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*/
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ServerHandler handler = connectedServers.get(
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message.getChangeNumber().getServerId());
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if (handler != null)
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handler.ack(message, fromServerId);
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else
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{
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ServerHandler.ackChangelog(message, fromServerId);
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}
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}
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/**
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* Retrieves the destination handlers for a routable message.
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*
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* @param msg The message to route.
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* @param senderHandler The handler of the server that published this message.
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* @return The list of destination handlers.
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*/
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protected List<ServerHandler> getDestinationServers(RoutableMessage msg,
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ServerHandler senderHandler)
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{
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List<ServerHandler> servers =
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new ArrayList<ServerHandler>();
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if (msg.getDestination() == RoutableMessage.THE_CLOSEST_SERVER)
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{
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// TODO Import from the "closest server" to be implemented
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}
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else if (msg.getDestination() == RoutableMessage.ALL_SERVERS)
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{
|
if (!senderHandler.isReplicationServer())
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{
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// Send to all replicationServers
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for (ServerHandler destinationHandler : replicationServers.values())
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{
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servers.add(destinationHandler);
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}
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}
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// Sends to all connected LDAP servers
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for (ServerHandler destinationHandler : connectedServers.values())
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{
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// Don't loop on the sender
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if (destinationHandler == senderHandler)
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continue;
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servers.add(destinationHandler);
|
}
|
}
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else
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{
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// Destination is one server
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ServerHandler destinationHandler =
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connectedServers.get(msg.getDestination());
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if (destinationHandler != null)
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{
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servers.add(destinationHandler);
|
}
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else
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{
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// the targeted server is NOT connected
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// Let's search for THE changelog server that MAY
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// have the targeted server connected.
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if (senderHandler.isLDAPserver())
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{
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for (ServerHandler h : replicationServers.values())
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{
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if (h.isRemoteLDAPServer(msg.getDestination()))
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{
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servers.add(h);
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}
|
}
|
}
|
}
|
}
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return servers;
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}
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|
/**
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* Process an InitializeRequestMessage.
|
*
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* @param msg The message received and to be processed.
|
* @param senderHandler The server handler of the server that emitted
|
* the message.
|
*/
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public void process(RoutableMessage msg, ServerHandler senderHandler)
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{
|
|
List<ServerHandler> servers = getDestinationServers(msg, senderHandler);
|
|
if (servers.isEmpty())
|
{
|
ErrorMessage errMsg = new ErrorMessage(
|
msg.getsenderID(), MSGID_NO_REACHABLE_PEER_IN_THE_DOMAIN,
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"serverID:" + msg.getDestination());
|
try
|
{
|
senderHandler.send(errMsg);
|
}
|
catch(IOException ioe)
|
{
|
// TODO Handle error properly (sender timeout in addition)
|
/*
|
* An error happened trying the send back an ack to this server.
|
* Log an error and close the connection to this server.
|
*/
|
int msgID = MSGID_CHANGELOG_ERROR_SENDING_ERROR;
|
String message = getMessage(msgID, this.toString())
|
+ stackTraceToSingleLineString(ioe);
|
logError(ErrorLogCategory.SYNCHRONIZATION,
|
ErrorLogSeverity.SEVERE_ERROR,
|
message, msgID);
|
senderHandler.shutdown();
|
}
|
}
|
else
|
{
|
for (ServerHandler targetHandler : servers)
|
{
|
try
|
{
|
targetHandler.send(msg);
|
}
|
catch(IOException ioe)
|
{
|
/*
|
* An error happened trying the send back an ack to this server.
|
* Log an error and close the connection to this server.
|
*/
|
int msgID = MSGID_CHANGELOG_ERROR_SENDING_MSG;
|
String message = getMessage(msgID, this.toString())
|
+ stackTraceToSingleLineString(ioe) + " "
|
+ msg.getClass().getCanonicalName();
|
logError(ErrorLogCategory.SYNCHRONIZATION,
|
ErrorLogSeverity.SEVERE_ERROR,
|
message, msgID);
|
senderHandler.shutdown();
|
// TODO Handle error properly (sender timeout in addition)
|
}
|
}
|
}
|
|
}
|
|
/**
|
* Send back an ack to the server that sent the change.
|
*
|
* @param changeNumber The ChangeNumber of the change that must be acked.
|
* @param isLDAPserver This boolean indicates if the server that sent the
|
* change was an LDAP server or a ReplicationServer.
|
*/
|
public void sendAck(ChangeNumber changeNumber, boolean isLDAPserver)
|
{
|
short serverId = changeNumber.getServerId();
|
sendAck(changeNumber, isLDAPserver, serverId);
|
}
|
|
/**
|
*
|
* Send back an ack to a server that sent the change.
|
*
|
* @param changeNumber The ChangeNumber of the change that must be acked.
|
* @param isLDAPserver This boolean indicates if the server that sent the
|
* change was an LDAP server or a ReplicationServer.
|
* @param serverId The identifier of the server from which we
|
* received the change..
|
*/
|
public void sendAck(ChangeNumber changeNumber, boolean isLDAPserver,
|
short serverId)
|
{
|
ServerHandler handler;
|
if (isLDAPserver)
|
handler = connectedServers.get(serverId);
|
else
|
handler = replicationServers.get(serverId);
|
|
// TODO : check for null handler and log error
|
try
|
{
|
handler.sendAck(changeNumber);
|
} catch (IOException e)
|
{
|
/*
|
* An error happened trying the send back an ack to this server.
|
* Log an error and close the connection to this server.
|
*/
|
int msgID = MSGID_CHANGELOG_ERROR_SENDING_ACK;
|
String message = getMessage(msgID, this.toString())
|
+ stackTraceToSingleLineString(e);
|
logError(ErrorLogCategory.SYNCHRONIZATION,
|
ErrorLogSeverity.SEVERE_ERROR,
|
message, msgID);
|
handler.shutdown();
|
}
|
}
|
|
/**
|
* Shutdown this ReplicationCache.
|
*/
|
public void shutdown()
|
{
|
// Close session with other changelogs
|
for (ServerHandler serverHandler : replicationServers.values())
|
{
|
serverHandler.shutdown();
|
}
|
|
// Close session with other LDAP servers
|
for (ServerHandler serverHandler : connectedServers.values())
|
{
|
serverHandler.shutdown();
|
}
|
|
// Shutdown the dbHandlers
|
synchronized (sourceDbHandlers)
|
{
|
for (DbHandler dbHandler : sourceDbHandlers.values())
|
{
|
dbHandler.shutdown();
|
}
|
sourceDbHandlers.clear();
|
}
|
}
|
|
/**
|
* Returns the ServerState describing the last change from this replica.
|
*
|
* @return The ServerState describing the last change from this replica.
|
*/
|
public ServerState getDbServerState()
|
{
|
ServerState serverState = new ServerState();
|
for (DbHandler db : sourceDbHandlers.values())
|
{
|
serverState.update(db.getLastChange());
|
}
|
return serverState;
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public String toString()
|
{
|
return "ReplicationCache " + baseDn;
|
}
|
|
/**
|
* Check if some server Handler should be removed from flow control state.
|
* @throws IOException If an error happened.
|
*/
|
public void checkAllSaturation() throws IOException
|
{
|
for (ServerHandler handler : replicationServers.values())
|
{
|
handler.checkWindow();
|
}
|
|
for (ServerHandler handler : connectedServers.values())
|
{
|
handler.checkWindow();
|
}
|
}
|
|
/**
|
* Check if a server that was in flow control can now restart
|
* sending updates.
|
* @param sourceHandler The server that must be checked.
|
* @return true if the server can restart sending changes.
|
* false if the server can't restart sending changes.
|
*/
|
public boolean restartAfterSaturation(ServerHandler sourceHandler)
|
{
|
for (ServerHandler handler : replicationServers.values())
|
{
|
if (!handler.restartAfterSaturation(sourceHandler))
|
return false;
|
}
|
|
for (ServerHandler handler : connectedServers.values())
|
{
|
if (!handler.restartAfterSaturation(sourceHandler))
|
return false;
|
}
|
return true;
|
}
|
|
/**
|
* Send a ReplServerInfoMessage to all the connected replication servers
|
* in order to let them know our connected LDAP servers.
|
*/
|
private void sendReplServerInfo()
|
{
|
ReplServerInfoMessage info =
|
new ReplServerInfoMessage(getConnectedLDAPservers());
|
for (ServerHandler handler : replicationServers.values())
|
{
|
try
|
{
|
handler.sendInfo(info);
|
}
|
catch (IOException e)
|
{
|
/*
|
* An error happened trying the send back an ack to this server.
|
* Log an error and close the connection to this server.
|
*/
|
int msgID = MSGID_CHANGELOG_ERROR_SENDING_INFO;
|
String message = getMessage(msgID, this.toString())
|
+ stackTraceToSingleLineString(e);
|
logError(ErrorLogCategory.SYNCHRONIZATION,
|
ErrorLogSeverity.SEVERE_ERROR,
|
message, msgID);
|
handler.shutdown();
|
}
|
}
|
}
|
|
/**
|
* Sets the replication server informations for the provided
|
* handler from the provided ReplServerInfoMessage.
|
*
|
* @param handler The server handler from which the info was received.
|
* @param infoMsg The information message that was received.
|
*/
|
public void setReplServerInfo(
|
ServerHandler handler, ReplServerInfoMessage infoMsg)
|
{
|
handler.setReplServerInfo(infoMsg);
|
}
|
}
|
