/*
* 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.synapse.core.axis2;
import org.apache.axis2.clustering.ClusteringAgent;
import org.apache.axis2.clustering.Member;
import org.apache.axis2.clustering.management.GroupManagementAgent;
import org.apache.axis2.context.ConfigurationContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.SynapseException;
import org.apache.synapse.core.LoadBalanceMembershipHandler;
import org.apache.synapse.endpoints.algorithms.AlgorithmContext;
import org.apache.synapse.endpoints.algorithms.LoadbalanceAlgorithm;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
/**
* Bridge between Axis2 membership notification and Synapse load balancing
*/
public class ServiceLoadBalanceMembershipHandler implements LoadBalanceMembershipHandler {
private static final Log log = LogFactory.getLog(ServiceLoadBalanceMembershipHandler.class);
private ConfigurationContext configCtx;
/**
* Key - Host, Value - DomainAlgorithmContext
*/
private Map<String, DomainAlgorithmContext> hostDomainAlgorithmContextMap =
new HashMap<String, DomainAlgorithmContext>();
private ClusteringAgent clusteringAgent;
public ServiceLoadBalanceMembershipHandler(Map<String, String> hostDomainMap,
LoadbalanceAlgorithm algorithm,
ConfigurationContext configCtx,
boolean isClusteringEnabled,
String endpointName) {
for (Map.Entry<String, String> entry : hostDomainMap.entrySet()) {
AlgorithmContext algorithmContext =
new AlgorithmContext(isClusteringEnabled, configCtx, endpointName + "." + entry.getKey());
this.hostDomainAlgorithmContextMap.put(entry.getKey(),
new DomainAlgorithmContext(entry.getValue(), algorithm.clone(), algorithmContext));
}
}
public void init(Properties props, LoadbalanceAlgorithm algorithm) {
// Nothing to do
}
public void setConfigurationContext(ConfigurationContext configCtx) {
this.configCtx = configCtx;
// The following code does the bridging between Axis2 and Synapse load balancing
clusteringAgent = configCtx.getAxisConfiguration().getClusteringAgent();
if(clusteringAgent == null){
String msg = "In order to enable load balancing across an Axis2 cluster, " +
"the cluster entry should be enabled in the axis2.xml file";
log.error(msg);
throw new SynapseException(msg);
}
}
public ConfigurationContext getConfigurationContext(){
return configCtx;
}
/**
* Getting the next member to which the request has to be sent in a round-robin fashion
*
* @param context The AlgorithmContext
* @return The current member
* @deprecated Use {@link #getNextApplicationMember(String)}
*/
public Member getNextApplicationMember(AlgorithmContext context) {
throw new UnsupportedOperationException("This operation is invalid. " +
"Call getNextApplicationMember(String host)");
}
public Member getNextApplicationMember(String host) {
DomainAlgorithmContext domainAlgorithmContext = getDomainAlgorithmContext(host);
String lbDomain = domainAlgorithmContext.getDomain();
LoadbalanceAlgorithm algorithm = domainAlgorithmContext.getAlgorithm();
GroupManagementAgent groupMgtAgent = clusteringAgent.getGroupManagementAgent(lbDomain);
if(groupMgtAgent == null){
String msg =
"A LoadBalanceEventHandler has not been specified in the axis2.xml " +
"file for the domain " + lbDomain + " for host " + host;
log.error(msg);
throw new SynapseException(msg);
}
algorithm.setApplicationMembers(groupMgtAgent.getMembers());
AlgorithmContext context = domainAlgorithmContext.getAlgorithmContext();
return algorithm.getNextApplicationMember(context);
}
private DomainAlgorithmContext getDomainAlgorithmContext(String host) {
DomainAlgorithmContext domainAlgorithmContext = hostDomainAlgorithmContextMap.get(host);
if(domainAlgorithmContext == null) {
int indexOfDot;
if ((indexOfDot = host.indexOf(".")) != -1) {
domainAlgorithmContext = getDomainAlgorithmContext(host.substring(indexOfDot + 1));
} else {
throw new SynapseException("Domain not found for host" + host);
}
}
return domainAlgorithmContext;
}
public LoadbalanceAlgorithm getLoadbalanceAlgorithm() {
return null;
}
public Properties getProperties() {
return null;
}
/**
* POJO for maintaining the domain & AlgorithmContext for a particular host
*/
private static class DomainAlgorithmContext {
// The clustering domain
private String domain;
private AlgorithmContext algorithmContext;
private LoadbalanceAlgorithm algorithm;
private DomainAlgorithmContext(String domain, LoadbalanceAlgorithm algorithm,
AlgorithmContext algorithmContext) {
this.domain = domain;
this.algorithm = algorithm;
this.algorithmContext = algorithmContext;
}
public LoadbalanceAlgorithm getAlgorithm() {
return algorithm;
}
public String getDomain() {
return domain;
}
public AlgorithmContext getAlgorithmContext() {
return algorithmContext;
}
}
}