/*
|
* 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
|
*
|
*
|
* Portions Copyright 2006-2007 Sun Microsystems, Inc.
|
*/
|
package org.opends.server.replication.server;
|
|
import static org.opends.server.loggers.Error.logError;
|
import static org.opends.server.messages.MessageHandler.getMessage;
|
import static org.opends.server.messages.ReplicationMessages.*;
|
import static org.opends.server.util.StaticUtils.stackTraceToSingleLineString;
|
|
import java.io.IOException;
|
import java.util.ArrayList;
|
import java.util.LinkedHashSet;
|
import java.util.List;
|
import java.util.Map;
|
import java.util.Set;
|
import java.util.concurrent.ConcurrentHashMap;
|
|
import org.opends.server.replication.common.ChangeNumber;
|
import org.opends.server.replication.common.ServerState;
|
import org.opends.server.replication.protocol.AckMessage;
|
import org.opends.server.replication.protocol.ErrorMessage;
|
import org.opends.server.replication.protocol.InitializeRequestMessage;
|
import org.opends.server.replication.protocol.RoutableMessage;
|
import org.opends.server.replication.protocol.UpdateMessage;
|
import org.opends.server.types.DN;
|
import org.opends.server.types.ErrorLogCategory;
|
import org.opends.server.types.ErrorLogSeverity;
|
|
import com.sleepycat.je.DatabaseException;
|
|
/**
|
* This class define an in-memory cache that will be used to store
|
* the messages that have been received from an LDAP server or
|
* from another changelog server and that should be forwarded to
|
* other servers.
|
*
|
* The size of the cache is set by configuration.
|
* If the cache becomes bigger than the configured size, the older messages
|
* are removed and should they be needed again must be read from the backing
|
* file
|
*
|
*
|
* it runs a thread that is responsible for saving the messages
|
* received to the disk and for trimming them
|
* Decision to trim can be based on disk space or age of the message
|
*/
|
public class ChangelogCache
|
{
|
private Object flowControlLock = new Object();
|
private DN baseDn = null;
|
|
/*
|
* The following map contains one balanced tree for each replica ID
|
* to which we are currently publishing
|
* the first update in the balanced tree is the next change that we
|
* must push to this particular server
|
*
|
* We add new TreeSet in the HashMap when a new server register
|
* to this changelog server.
|
*
|
*/
|
private Map<Short, ServerHandler> connectedServers =
|
new ConcurrentHashMap<Short, ServerHandler>();
|
|
/*
|
* This map contains one ServerHandler for each changelog servers
|
* with which we are connected (so normally all the changelogs)
|
* the first update in the balanced tree is the next change that we
|
* must push to this particular server
|
*
|
* We add new TreeSet in the HashMap when a new changelog server register
|
* to this changelog server.
|
*/
|
private Map<Short, ServerHandler> changelogServers =
|
new ConcurrentHashMap<Short, ServerHandler>();
|
|
/*
|
* This map contains the List of updates received from each
|
* LDAP server
|
*/
|
private Map<Short, DbHandler> sourceDbHandlers =
|
new ConcurrentHashMap<Short, DbHandler>();
|
private Changelog changelog;
|
|
/**
|
* Creates a new ChangelogCache associated to the DN baseDn.
|
*
|
* @param baseDn The baseDn associated to the ChangelogCache.
|
* @param changelog the Changelog that created this changelog cache.
|
*/
|
public ChangelogCache(DN baseDn, Changelog changelog)
|
{
|
this.baseDn = baseDn;
|
this.changelog = changelog;
|
}
|
|
/**
|
* Add an update that has been received to the list of
|
* updates that must be forwarded to all other servers.
|
*
|
* @param update The update that has been received.
|
* @param sourceHandler The ServerHandler for the server from which the
|
* update was received
|
* @throws IOException When an IO exception happens during the update
|
* processing.
|
*/
|
public void put(UpdateMessage update, ServerHandler sourceHandler)
|
throws IOException
|
{
|
/*
|
* TODO : In case that the source server is a LDAP server this method
|
* should check that change did get pushed to at least one
|
* other changelog server before pushing it to the LDAP servers
|
*/
|
|
sourceHandler.updateServerState(update);
|
sourceHandler.incrementInCount();
|
|
if (update.isAssured())
|
{
|
int count = this.NumServers();
|
if (count > 1)
|
{
|
if (sourceHandler.isChangelogServer())
|
ServerHandler.addWaitingAck(update, sourceHandler.getServerId(),
|
this, count - 1);
|
else
|
sourceHandler.addWaitingAck(update, count - 1);
|
}
|
else
|
{
|
sourceHandler.sendAck(update.getChangeNumber());
|
}
|
}
|
|
// look for the dbHandler that is responsible for the master server which
|
// generated the change.
|
DbHandler dbHandler = null;
|
synchronized (sourceDbHandlers)
|
{
|
short id = update.getChangeNumber().getServerId();
|
dbHandler = sourceDbHandlers.get(id);
|
if (dbHandler == null)
|
{
|
try
|
{
|
dbHandler = changelog.newDbHandler(id, baseDn);
|
} catch (DatabaseException e)
|
{
|
/*
|
* Because of database problem we can't save any more changes
|
* from at least one LDAP server.
|
* This changelog therefore can't do it's job properly anymore
|
* and needs to close all its connections and shutdown itself.
|
*/
|
int msgID = MSGID_CHANGELOG_SHUTDOWN_DATABASE_ERROR;
|
String message = getMessage(msgID) + stackTraceToSingleLineString(e);
|
logError(ErrorLogCategory.SYNCHRONIZATION,
|
ErrorLogSeverity.SEVERE_ERROR,
|
message, msgID);
|
changelog.shutdown();
|
return;
|
}
|
sourceDbHandlers.put(id, dbHandler);
|
}
|
}
|
|
// Publish the messages to the source handler
|
dbHandler.add(update);
|
|
|
/*
|
* Push the message to the changelog servers
|
*/
|
if (!sourceHandler.isChangelogServer())
|
{
|
for (ServerHandler handler : changelogServers.values())
|
{
|
handler.add(update, sourceHandler);
|
}
|
}
|
|
/*
|
* Push the message to the LDAP servers
|
*/
|
for (ServerHandler handler : connectedServers.values())
|
{
|
// don't forward the change to the server that just sent it
|
if (handler == sourceHandler)
|
{
|
continue;
|
}
|
|
handler.add(update, sourceHandler);
|
}
|
|
|
|
}
|
|
/**
|
* Create initialize context necessary for finding the changes
|
* that must be sent to a given LDAP or changelog server.
|
*
|
* @param handler handler for the server that must be started
|
* @throws Exception when method has failed
|
*/
|
public void startServer(ServerHandler handler) throws Exception
|
{
|
/*
|
* create the balanced tree that will be used to forward changes
|
*/
|
synchronized (connectedServers)
|
{
|
if (connectedServers.containsKey(handler.getServerId()))
|
{
|
/* TODO : handle error properly */
|
throw new Exception("serverId already registered");
|
}
|
connectedServers.put(handler.getServerId(), handler);
|
}
|
}
|
|
/**
|
* Stop operations with a given server.
|
*
|
* @param handler the server for which we want to stop operations
|
*/
|
public void stopServer(ServerHandler handler)
|
{
|
handler.stopHandler();
|
|
if (handler.isChangelogServer())
|
changelogServers.remove(handler.getServerId());
|
else
|
connectedServers.remove(handler.getServerId());
|
}
|
|
/**
|
* Create initialize context necessary for finding the changes
|
* that must be sent to a given changelog server.
|
*
|
* @param handler the server ID to which we want to forward changes
|
* @throws Exception in case of errors
|
*/
|
public void startChangelog(ServerHandler handler) throws Exception
|
{
|
/*
|
* create the balanced tree that will be used to forward changes
|
* TODO throw proper exception
|
*/
|
synchronized (changelogServers)
|
{
|
if (changelogServers.containsKey(handler.getServerId()))
|
{
|
throw new Exception("changelog Id already registered");
|
}
|
changelogServers.put(handler.getServerId(), handler);
|
}
|
}
|
|
/**
|
* Get the next update that need to be sent to a given LDAP server.
|
* This call is blocking when no update is available or when dependencies
|
* do not allow to send the next available change
|
*
|
* @param handler The server handler for the target directory server.
|
*
|
* @return the update that must be forwarded
|
*/
|
public UpdateMessage take(ServerHandler handler)
|
{
|
UpdateMessage msg;
|
/*
|
* Get the balanced tree that we use to sort the changes to be
|
* sent to the replica from the cookie
|
*
|
* The next change to send is always the first one in the tree
|
* So this methods simply need to check that dependencies are OK
|
* and update this replicaId RUV
|
*
|
* TODO : dependency :
|
* before forwarding change, we should check that the dependency
|
* that is indicated in this change is OK (change already in the RUV)
|
*/
|
msg = handler.take();
|
synchronized (flowControlLock)
|
{
|
if (handler.restartAfterSaturation(null))
|
flowControlLock.notifyAll();
|
}
|
return msg;
|
}
|
|
/**
|
* Return a Set of String containing the lists of Changelog servers
|
* connected to this server.
|
* @return the set of connected servers
|
*/
|
public Set<String> getChangelogs()
|
{
|
LinkedHashSet<String> mySet = new LinkedHashSet<String>();
|
|
for (ServerHandler handler : changelogServers.values())
|
{
|
mySet.add(handler.getServerAddressURL());
|
}
|
|
return mySet;
|
}
|
|
|
/**
|
* Return a Set containing the servers known by this changelog.
|
* @return a set containing the servers known by this changelog.
|
*/
|
public Set<Short> getServers()
|
{
|
return sourceDbHandlers.keySet();
|
}
|
|
|
/**
|
* Creates and returns an iterator.
|
*
|
* @param serverId Identifier of the server for which the iterator is created.
|
* @param changeNumber Starting point for the iterator.
|
* @return the created ChangelogIterator.
|
*/
|
public ChangelogIterator getChangelogIterator(short serverId,
|
ChangeNumber changeNumber)
|
{
|
DbHandler handler = sourceDbHandlers.get(serverId);
|
if (handler == null)
|
return null;
|
|
try
|
{
|
return handler.generateIterator(changeNumber);
|
}
|
catch (Exception e) {
|
return null;
|
}
|
}
|
|
/**
|
* Get the baseDn.
|
* @return Returns the baseDn.
|
*/
|
public DN getBaseDn()
|
{
|
return baseDn;
|
}
|
|
/**
|
* creates a new ChangelogDB with specified identifier.
|
* @param id the identifier of the new ChangelogDB.
|
* @param db the new db.
|
*
|
* @throws DatabaseException If a database error happened.
|
*/
|
public void newDb(short id, DbHandler db) throws DatabaseException
|
{
|
synchronized (sourceDbHandlers)
|
{
|
sourceDbHandlers.put(id , db);
|
}
|
}
|
|
/**
|
* Get the number of currently connected servers.
|
*
|
* @return the number of currently connected servers.
|
*/
|
private int NumServers()
|
{
|
return changelogServers.size() + connectedServers.size();
|
}
|
|
|
/**
|
* Add an ack to the list of ack received for a given change.
|
*
|
* @param message The ack message received.
|
* @param fromServerId The identifier of the server that sent the ack.
|
*/
|
public void ack(AckMessage message, short fromServerId)
|
{
|
/*
|
* there are 2 possible cases here :
|
* - the message that was acked comes from a server to which
|
* we are directly connected.
|
* In this case, we can find the handler from the connectedServers map
|
* - the message that was acked comes from a server to which we are not
|
* connected.
|
* In this case we need to find the changelog server that forwarded
|
* the change and send back the ack to this server.
|
*/
|
ServerHandler handler = connectedServers.get(
|
message.getChangeNumber().getServerId());
|
if (handler != null)
|
handler.ack(message, fromServerId);
|
else
|
{
|
ServerHandler.ackChangelog(message, fromServerId);
|
}
|
}
|
|
/**
|
* Retrieves the destination handlers for a routable message.
|
*
|
* @param msg The message to route.
|
* @param senderHandler The handler of the server that published this message.
|
* @return The list of destination handlers.
|
*/
|
protected List<ServerHandler> getDestinationServers(RoutableMessage msg,
|
ServerHandler senderHandler)
|
{
|
|
List<ServerHandler> servers =
|
new ArrayList<ServerHandler>();
|
|
logError(ErrorLogCategory.SYNCHRONIZATION,
|
ErrorLogSeverity.SEVERE_ERROR,
|
"getDestinationServers"
|
+ " msgDest:" + msg.getDestination() , 1);
|
|
if (msg.getDestination() == RoutableMessage.THE_CLOSEST_SERVER)
|
{
|
// TODO Import from the "closest server" to be implemented
|
}
|
else if (msg.getDestination() == RoutableMessage.ALL_SERVERS)
|
{
|
if (!senderHandler.isChangelogServer())
|
{
|
// Send to all changelogServers
|
for (ServerHandler destinationHandler : changelogServers.values())
|
{
|
servers.add(destinationHandler);
|
}
|
}
|
|
// Send to all connected LDAP servers
|
for (ServerHandler destinationHandler : connectedServers.values())
|
{
|
// Don't loop on the sender
|
if (destinationHandler == senderHandler)
|
continue;
|
servers.add(destinationHandler);
|
}
|
}
|
else
|
{
|
// Destination is one server
|
ServerHandler destinationHandler =
|
connectedServers.get(msg.getDestination());
|
if (destinationHandler != null)
|
{
|
servers.add(destinationHandler);
|
}
|
else
|
{
|
// the targeted server is NOT connected
|
if (senderHandler.isLDAPserver())
|
{
|
// let's forward to the other changelogs
|
servers.addAll(changelogServers.values());
|
}
|
}
|
}
|
|
return servers;
|
}
|
|
/**
|
* Process an InitializeRequestMessage.
|
*
|
* @param msg The message received and to be processed.
|
* @param senderHandler The server handler of the server that emitted
|
* the message.
|
*/
|
public void process(RoutableMessage msg, ServerHandler senderHandler)
|
{
|
|
List<ServerHandler> servers = getDestinationServers(msg, senderHandler);
|
|
if (servers.isEmpty())
|
{
|
if (!(msg instanceof InitializeRequestMessage))
|
{
|
// TODO A more elaborated policy is probably needed
|
}
|
else
|
{
|
ErrorMessage errMsg = new ErrorMessage(
|
msg.getsenderID(), MSGID_NO_REACHABLE_PEER_IN_THE_DOMAIN,
|
"serverID:" + msg.getDestination());
|
|
try
|
{
|
senderHandler.send(errMsg);
|
}
|
catch(IOException ioe)
|
{
|
// TODO Handle error properly (sender timeout in addition)
|
}
|
}
|
return;
|
}
|
|
for (ServerHandler targetHandler : servers)
|
{
|
try
|
{
|
targetHandler.send(msg);
|
}
|
catch(IOException ioe)
|
{
|
// 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 Changelog server.
|
*/
|
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 Changelog server.
|
* @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 = changelogServers.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 ChangelogCache.
|
*/
|
public void shutdown()
|
{
|
// Close session with other changelogs
|
for (ServerHandler serverHandler : changelogServers.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 "ChangelogCache " + 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 : changelogServers.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 : changelogServers.values())
|
{
|
if (!handler.restartAfterSaturation(sourceHandler))
|
return false;
|
}
|
|
for (ServerHandler handler : connectedServers.values())
|
{
|
if (!handler.restartAfterSaturation(sourceHandler))
|
return false;
|
}
|
return true;
|
}
|
}
|
