/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.axis2.clustering.context;
import org.apache.axis2.clustering.ClusterManager;
import org.apache.axis2.clustering.ClusteringFault;
import org.apache.axis2.clustering.ClusteringConstants;
import org.apache.axis2.context.AbstractContext;
import org.apache.axis2.context.ConfigurationContext;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.context.ServiceContext;
import org.apache.axis2.context.ServiceGroupContext;
import org.apache.axis2.engine.AxisConfiguration;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.ArrayList;
import java.util.List;
public final class Replicator {
private static final Log log = LogFactory.getLog(Replicator.class);
public static void replicate(MessageContext msgContext) throws ClusteringFault {
if (!doReplication(msgContext)) {
return;
}
log.debug("Going to replicate state...");
try {
replicateState(msgContext);
} catch (Exception e) {
String message = "Could not replicate the state";
log.error(message, e);
throw new ClusteringFault(message, e);
}
}
public static void replicate(AbstractContext abstractContext) throws ClusteringFault {
if (!doReplication(abstractContext)) {
return;
}
log.debug("Going to replicate state...");
try {
replicateState(abstractContext);
} catch (Exception e) {
String message = "Could not replicate the state";
log.error(message, e);
throw new ClusteringFault(message, e);
}
}
/**
* Do replication only if context replication is enabled.
* Also note that if there are no members, we need not do any replication
*
* @param abstractContext
* @return true - State needs to be replicated
* false - otherwise
*/
private static boolean doReplication(AbstractContext abstractContext) {
ClusterManager clusterManager =
abstractContext.getRootContext().getAxisConfiguration().getClusterManager();
return clusterManager != null &&
clusterManager.getContextManager() != null;
}
private static void replicateState(AbstractContext abstractContext) throws ClusteringFault {
ClusterManager clusterManager =
abstractContext.getRootContext().getAxisConfiguration().getClusterManager();
if (clusterManager != null) {
ContextManager contextManager = clusterManager.getContextManager();
if (contextManager == null) {
String msg = "Cannot replicate contexts since " +
"ContextManager is not specified in the axis2.xml file.";
throw new ClusteringFault(msg);
}
if (!abstractContext.getPropertyDifferences().isEmpty()) {
String msgUUID = contextManager.updateContext(abstractContext);
waitForACKs(contextManager, msgUUID, abstractContext.getRootContext());
}
} else {
String msg = "Cannot replicate contexts since " +
"ClusterManager is not specified in the axis2.xml file.";
throw new ClusteringFault(msg);
}
}
private static void replicateState(MessageContext msgContext) throws ClusteringFault {
ConfigurationContext configurationContext = msgContext.getConfigurationContext();
AxisConfiguration axisConfiguration = configurationContext.getAxisConfiguration();
ClusterManager clusterManager = axisConfiguration.getClusterManager();
if (clusterManager != null) {
ContextManager contextManager = clusterManager.getContextManager();
if (contextManager == null) {
String msg = "Cannot replicate contexts since " +
"ContextManager is not specified in the axis2.xml file.";
throw new ClusteringFault(msg);
}
List contexts = new ArrayList();
// Do we need to replicate state stored in ConfigurationContext?
if (!configurationContext.getPropertyDifferences().isEmpty()) {
contexts.add(configurationContext);
}
// Do we need to replicate state stored in ServiceGroupContext?
ServiceGroupContext sgContext = msgContext.getServiceGroupContext();
if (sgContext != null && !sgContext.getPropertyDifferences().isEmpty()) {
contexts.add(sgContext);
}
// Do we need to replicate state stored in ServiceContext?
ServiceContext serviceContext = msgContext.getServiceContext();
if (serviceContext != null && !serviceContext.getPropertyDifferences().isEmpty()) {
contexts.add(serviceContext);
}
// Do the actual replication here
if (!contexts.isEmpty()) {
AbstractContext[] contextArray =
(AbstractContext[]) contexts.toArray(new AbstractContext[contexts.size()]);
String msgUUID = contextManager.updateContexts(contextArray);
waitForACKs(contextManager, msgUUID, msgContext.getRootContext());
}
} else {
String msg = "Cannot replicate contexts since " +
"ClusterManager is not specified in the axis2.xml file.";
throw new ClusteringFault(msg);
}
}
private static void waitForACKs(ContextManager contextManager,
String msgUUID,
ConfigurationContext configCtx) throws ClusteringFault {
long start = System.currentTimeMillis();
// Wait till all members have ACKed receipt & successful processing of
// the message with UUID 'msgUUID'
do {
// Wait sometime before checking whether message is ACKed
try {
Long tts =
(Long) configCtx.getPropertyNonReplicable(ClusteringConstants.TIME_TO_SEND);
if (tts == null) {
Thread.sleep(5);
} else if (tts.longValue() >= 0) {
Thread.sleep(tts.longValue() + 5); // Time to recv ACK + time in queue & processing replication request
}
} catch (InterruptedException ignored) {
}
if (System.currentTimeMillis() - start > 45000) {
throw new ClusteringFault("ACKs not received from all members within 45 sec. " +
"Aborting wait.");
}
} while (!contextManager.isMessageAcknowledged(msgUUID));
}
}