oscache 集群和数据同步
cache.event.listeners=com.test.JavaGroupsBroadcastingListenerImpl cache.cluster.properties=UDP(mcast_addr=231.12.21.132;mcast_port=45566;ip_ttl=32;\ mcast_send_buf_size=150000;mcast_recv_buf_size=80000):\ PING(timeout=2000;num_initial_members=3):\ MERGE2(min_interval=5000;max_interval=10000):\ FD_SOCK:VERIFY_SUSPECT(timeout=1500):\ pbcast.NAKACK(gc_lag=50;retransmit_timeout=300,600,1200,2400,4800;max_xmit_size=8192):\ UNICAST(timeout=300,600,1200,2400):\ pbcast.STABLE(desired_avg_gossip=20000):\ FRAG(frag_size=8096;down_thread=false;up_thread=false):\ pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;shun=false;print_local_addr=true) cache.cluster.multicast.ip=231.12.21.132
oscache 集群同步数据需要使用到JavaGroupsBroadcastingListener，但是JavaGroupsBroadcastingListener 具体没有实现同步的功能，JavaGroupsBroadcastingListener：
public void handleNotification(Serializable serializable) {
if (!(serializable instanceof ClusterNotification)) {
log.error("An unknown cluster notification message received (class=" + serializable.getClass().getName() + "). Notification ignored.");
return;
}
handleClusterNotification((ClusterNotification) serializable);
}
handleNotification该方法调用 handleClusterNotification((ClusterNotification) serializable)后，进入AbstractBoardcasting类，改方法只执行刷新当前缓存的内容，对集群数据同步没有实现。
/*
* Copyright (c) 2002-2003 by OpenSymphony
* All rights reserved.
*/
package com.opensymphony.oscache.plugins.clustersupport;
import com.opensymphony.oscache.base.*;
import com.opensymphony.oscache.base.events.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.Date;
/**
* Implementation of a CacheEntryEventListener. It broadcasts the flush events
* across a cluster to other listening caches. Note that this listener cannot
* be used in conjection with session caches.
*
* @version $Revision: 254 $
* @author <a href="mailto:chris@swebtec.com">Chris Miller</a>
*/
public abstract class AbstractBroadcastingListener implements CacheEntryEventListener, LifecycleAware {
private final static Log log = LogFactory.getLog(AbstractBroadcastingListener.class);
/**
* The name to use for the origin of cluster events. Using this ensures
* events are not fired recursively back over the cluster.
*/
protected static final String CLUSTER_ORIGIN = "CLUSTER";
protected Cache cache = null;
public AbstractBroadcastingListener() {
if (log.isInfoEnabled()) {
log.info("AbstractBroadcastingListener registered");
}
}
/**
* Event fired when an entry is flushed from the cache. This broadcasts
* the flush message to any listening nodes on the network.
*/
public void cacheEntryFlushed(CacheEntryEvent event) {
if (!Cache.NESTED_EVENT.equals(event.getOrigin()) && !CLUSTER_ORIGIN.equals(event.getOrigin())) {
if (log.isDebugEnabled()) {
log.debug("cacheEntryFlushed called (" + event + ")");
}
sendNotification(new ClusterNotification(ClusterNotification.FLUSH_KEY, event.getKey()));
}
}
/**
* Event fired when an entry is removed from the cache. This broadcasts
* the remove method to any listening nodes on the network, as long as
* this event wasn't from a broadcast in the first place.
*/
public void cacheGroupFlushed(CacheGroupEvent event) {
if (!Cache.NESTED_EVENT.equals(event.getOrigin()) && !CLUSTER_ORIGIN.equals(event.getOrigin())) {
if (log.isDebugEnabled()) {
log.debug("cacheGroupFushed called (" + event + ")");
}
sendNotification(new ClusterNotification(ClusterNotification.FLUSH_GROUP, event.getGroup()));
}
}
public void cachePatternFlushed(CachePatternEvent event) {
if (!Cache.NESTED_EVENT.equals(event.getOrigin()) && !CLUSTER_ORIGIN.equals(event.getOrigin())) {
if (log.isDebugEnabled()) {
log.debug("cachePatternFushed called (" + event + ")");
}
sendNotification(new ClusterNotification(ClusterNotification.FLUSH_PATTERN, event.getPattern()));
}
}
public void cacheFlushed(CachewideEvent event) {
if (!Cache.NESTED_EVENT.equals(event.getOrigin()) && !CLUSTER_ORIGIN.equals(event.getOrigin())) {
if (log.isDebugEnabled()) {
log.debug("cacheFushed called (" + event + ")");
}
sendNotification(new ClusterNotification(ClusterNotification.FLUSH_CACHE, event.getDate()));
}
}
// --------------------------------------------------------
// The remaining events are of no interest to this listener
// --------------------------------------------------------
public void cacheEntryAdded(CacheEntryEvent event) {
}
public void cacheEntryRemoved(CacheEntryEvent event) {
}
public void cacheEntryUpdated(CacheEntryEvent event) {
}
public void cacheGroupAdded(CacheGroupEvent event) {
}
public void cacheGroupEntryAdded(CacheGroupEvent event) {
}
public void cacheGroupEntryRemoved(CacheGroupEvent event) {
}
public void cacheGroupRemoved(CacheGroupEvent event) {
}
public void cacheGroupUpdated(CacheGroupEvent event) {
}
/**
* Called by the cache administrator class when a cache is instantiated.
*
* @param cache the cache instance that this listener is attached to.
* @param config The cache's configuration details. This allows the event handler
* to initialize itself based on the cache settings, and also to receive <em>additional</em>
* settings that were part of the cache configuration but that the cache
* itself does not care about. If you are using <code>cache.properties</code>
* for your configuration, simply add any additional properties that your event
* handler requires and they will be passed through in this parameter.
*
* @throws InitializationException thrown when there was a problem initializing the
* listener. The cache administrator will log this error and disable the listener.
*/
public void initialize(Cache cache, Config config) throws InitializationException {
this.cache = cache;
}
/**
* Handles incoming notification messages. This method should be called by the
* underlying broadcasting implementation when a message is received from another
* node in the cluster.
*
* @param message The incoming cluster notification message object.
*/
public void handleClusterNotification(ClusterNotification message) {
if (cache == null) {
log.warn("A cluster notification (" + message + ") was received, but no cache is registered on this machine. Notification ignored.");
return;
}
if (log.isInfoEnabled()) {
log.info("Cluster notification (" + message + ") was received.");
}
switch (message.getType()) {
case ClusterNotification.FLUSH_KEY:
cache.flushEntry((String) message.getData(), CLUSTER_ORIGIN);
break;
case ClusterNotification.FLUSH_GROUP:
cache.flushGroup((String) message.getData(), CLUSTER_ORIGIN);
break;
case ClusterNotification.FLUSH_PATTERN:
cache.flushPattern((String) message.getData(), CLUSTER_ORIGIN);
break;
case ClusterNotification.FLUSH_CACHE:
cache.flushAll((Date) message.getData(), CLUSTER_ORIGIN);
break;
default:
log.error("The cluster notification (" + message + ") is of an unknown type. Notification ignored.");
}
}
/**
* Called when a cluster notification message is to be broadcast. Implementing
* classes should use their underlying transport to broadcast the message across
* the cluster.
*
* @param message The notification message to broadcast.
*/
abstract protected void sendNotification(ClusterNotification message);
}
所以我们要集群式同步数据，必须实现这三个方法：
public void cacheEntryAdded(CacheEntryEvent event) {
}
public void cacheEntryRemoved(CacheEntryEvent event) {
}
public void cacheEntryUpdated(CacheEntryEvent event) {
}
这个实现类实现了以上的三个方法，就可以同步数据了：
package com.test;
import com.opensymphony.oscache.base.events.CacheEntryEvent;
import com.opensymphony.oscache.plugins.clustersupport.ClusterNotification;
import com.opensymphony.oscache.plugins.clustersupport.JavaGroupsBroadcastingListener;
public class JavaGroupsBroadcastingListenerImpl extends
JavaGroupsBroadcastingListener {
public void handleClusterNotification(ClusterNotification message) {
switch (message.getType()) {
case CacheConstants.CLUSTER_ENTRY_ADD:
System.out.println("集群新增:" + message.getData());
if(message.getData() instanceof QflagCacheEvent) {
QflagCacheEvent event = (QflagCacheEvent)message.getData();
cache.putInCache(event.getKey(), event.getEntry().getContent(),null,null,CLUSTER_ORIGIN);
}
break;
case CacheConstants.CLUSTER_ENTRY_UPDATE:
System.out.println("集群更新:" + message.getData());
if(message.getData() instanceof QflagCacheEvent) {
QflagCacheEvent event = (QflagCacheEvent)message.getData();
// cache.flushEntry(event.getKey());
cache.putInCache(event.getKey(), event.getEntry().getContent(),null,null,CLUSTER_ORIGIN);
}
break;
case CacheConstants.CLUSTER_ENTRY_DELETE:
System.out.println("集群删除:" + message.getData());
if(message.getData() instanceof QflagCacheEvent) {
QflagCacheEvent event = (QflagCacheEvent)message.getData();
// cache.removeEntry(event.getKey(),event.getOrigin());
cache.removeEntry(event.getKey());
}
break;
}
}
public void cacheEntryAdded(CacheEntryEvent event) {
super.cacheEntryAdded(event);
System.out.println("属性添加");
if(!CLUSTER_ORIGIN.equals(event.getOrigin())) {
sendNotification(new ClusterNotification(CacheConstants.CLUSTER_ENTRY_ADD, new QflagCacheEvent(event.getMap(),event.getEntry(),CLUSTER_ORIGIN)));
}
}
// @Override
// public void cacheEntryFlushed(CacheEntryEvent event) {
//
// super.cacheEntryFlushed(event);
// if(!CLUSTER_ORIGIN.equals(event.getOrigin())) {
// sendNotification(new ClusterNotification(CacheConstants.CLUSTER_ENTRY_ADD, new UcallCacheEvent(event.getMap(),event.getEntry(),CLUSTER_ORIGIN)));
// }
// }
@Override
public void cacheEntryRemoved(CacheEntryEvent event) {
System.out.println("属性移除");
super.cacheEntryRemoved(event);
if(!CLUSTER_ORIGIN.equals(event.getOrigin())) {
sendNotification(new ClusterNotification(CacheConstants.CLUSTER_ENTRY_DELETE, new QflagCacheEvent(event.getMap(),event.getEntry(),CLUSTER_ORIGIN)));
}
}
@Override
public void cacheEntryUpdated(CacheEntryEvent event) {
System.out.println("属性更新");
super.cacheEntryUpdated(event);
if(!CLUSTER_ORIGIN.equals(event.getOrigin())) {
sendNotification(new ClusterNotification(CacheConstants.CLUSTER_ENTRY_UPDATE, new QflagCacheEvent(event.getMap(),event.getEntry(),CLUSTER_ORIGIN)));
}
}
}
然后修改配置文件，映射cache.event.listeners类的路径：
cache.event.listeners=com.test.JavaGroupsBroadcastingListenerImpl cache.cluster.properties=UDP(mcast_addr=231.12.21.132;mcast_port=45566;ip_ttl=32;\ mcast_send_buf_size=150000;mcast_recv_buf_size=80000):\ PING(timeout=2000;num_initial_members=3):\ MERGE2(min_interval=5000;max_interval=10000):\ FD_SOCK:VERIFY_SUSPECT(timeout=1500):\ pbcast.NAKACK(gc_lag=50;retransmit_timeout=300,600,1200,2400,4800;max_xmit_size=8192):\ UNICAST(timeout=300,600,1200,2400):\ pbcast.STABLE(desired_avg_gossip=20000):\ FRAG(frag_size=8096;down_thread=false;up_thread=false):\ pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;shun=false;print_local_addr=true) cache.cluster.multicast.ip=231.12.21.132
具体源码可以参考 oscache集群功能 http://rwl6813021.iteye.com/blog/246473，我已经实现了整合。
测试使用两个tomcat6.0，无问题，但是一个tomca6.0，一个tomcat7.0时发现缓存没有同步。。。