blob: 25e0ad7fe4859daff2dbf6057e9c4283a67643ff [file] [log] [blame]
package org.apache.jcs.auxiliary.remote;
/*
* 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.
*/
import java.io.IOException;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.jcs.auxiliary.AbstractAuxiliaryCacheEventLogging;
import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
import org.apache.jcs.auxiliary.remote.behavior.IRemoteCacheAttributes;
import org.apache.jcs.auxiliary.remote.behavior.IRemoteCacheClient;
import org.apache.jcs.auxiliary.remote.behavior.IRemoteCacheListener;
import org.apache.jcs.auxiliary.remote.behavior.IRemoteCacheService;
import org.apache.jcs.engine.CacheConstants;
import org.apache.jcs.engine.behavior.ICacheElement;
import org.apache.jcs.engine.behavior.ICacheElementSerialized;
import org.apache.jcs.engine.behavior.IZombie;
import org.apache.jcs.engine.logging.behavior.ICacheEventLogger;
import org.apache.jcs.engine.stats.StatElement;
import org.apache.jcs.engine.stats.Stats;
import org.apache.jcs.engine.stats.behavior.IStatElement;
import org.apache.jcs.engine.stats.behavior.IStats;
import org.apache.jcs.utils.serialization.SerializationConversionUtil;
import org.apache.jcs.utils.threadpool.ThreadPool;
import org.apache.jcs.utils.threadpool.ThreadPoolManager;
import EDU.oswego.cs.dl.util.concurrent.Callable;
import EDU.oswego.cs.dl.util.concurrent.FutureResult;
import EDU.oswego.cs.dl.util.concurrent.TimeoutException;
/** Abstract base for remote caches. I'm trying to break out and reuse common functionality. */
public abstract class AbstractRemoteAuxiliaryCache
extends AbstractAuxiliaryCacheEventLogging
implements IRemoteCacheClient
{
/** Don't change. */
private static final long serialVersionUID = -5329231850422826461L;
/** The logger. */
private final static Log log = LogFactory.getLog( AbstractRemoteAuxiliaryCache.class );
/**
* This does the work. In an RMI instances, it will be a remote reference. In an http remote
* cache it will be an http client. In zombie mode it is replaced with a balking facade.
*/
private IRemoteCacheService remoteCacheService;
/** The cacheName */
protected final String cacheName;
/** The listener. This can be null. */
private IRemoteCacheListener remoteCacheListener;
/** The configuration values. TODO, we'll need a base here. */
private IRemoteCacheAttributes remoteCacheAttributes;
/** A thread pool for gets if configured. */
private ThreadPool pool = null;
/** Should we get asynchronously using a pool. */
private boolean usePoolForGet = false;
/**
* Creates the base.
* <p>
* @param cattr
* @param remote
* @param listener
*/
public AbstractRemoteAuxiliaryCache( IRemoteCacheAttributes cattr, IRemoteCacheService remote,
IRemoteCacheListener listener )
{
this.setRemoteCacheAttributes( cattr );
this.cacheName = cattr.getCacheName();
this.setRemoteCacheService( remote );
this.setRemoteCacheListener( listener );
if ( log.isDebugEnabled() )
{
log.debug( "Construct> cacheName=" + cattr.getCacheName() );
log.debug( "irca = " + getRemoteCacheAttributes() );
log.debug( "remote = " + remote );
log.debug( "listener = " + listener );
}
// use a pool if it is greater than 0
if ( log.isDebugEnabled() )
{
log.debug( "GetTimeoutMillis() = " + getRemoteCacheAttributes().getGetTimeoutMillis() );
}
if ( getRemoteCacheAttributes().getGetTimeoutMillis() > 0 )
{
pool = ThreadPoolManager.getInstance().getPool( getRemoteCacheAttributes().getThreadPoolName() );
if ( log.isDebugEnabled() )
{
log.debug( "Thread Pool = " + pool );
}
if ( pool != null )
{
usePoolForGet = true;
}
}
}
/**
* Synchronously dispose the remote cache; if failed, replace the remote handle with a zombie.
* <p>
* @throws IOException
*/
protected void processDispose()
throws IOException
{
if ( log.isInfoEnabled() )
{
log.info( "Disposing of remote cache." );
}
try
{
if ( getRemoteCacheListener() != null )
{
getRemoteCacheListener().dispose();
}
}
catch ( Exception ex )
{
log.error( "Couldn't dispose", ex );
handleException( ex, "Failed to dispose [" + cacheName + "]", ICacheEventLogger.DISPOSE_EVENT );
}
}
/**
* Synchronously get from the remote cache; if failed, replace the remote handle with a zombie.
* <p>
* Use threadpool to timeout if a value is set for GetTimeoutMillis
* <p>
* If we are a cluster client, we need to leave the Element in its serialized form. Cluster
* clients cannot deserialize objects. Cluster clients get ICacheElementSerialized objects from
* other remote servers.
* <p>
* @param key
* @return ICacheElement, a wrapper around the key, value, and attributes
* @throws IOException
*/
protected ICacheElement processGet( Serializable key )
throws IOException
{
ICacheElement retVal = null;
try
{
if ( usePoolForGet )
{
retVal = getUsingPool( key );
}
else
{
retVal = getRemoteCacheService().get( cacheName, key, getListenerId() );
}
// Eventually the instance of will not be necessary.
if ( retVal != null && retVal instanceof ICacheElementSerialized )
{
// Never try to deserialize if you are a cluster client. Cluster
// clients are merely intra-remote cache communicators. Remote caches are assumed
// to have no ability to deserialze the objects.
if ( this.getRemoteCacheAttributes().getRemoteType() != IRemoteCacheAttributes.CLUSTER )
{
retVal = SerializationConversionUtil.getDeSerializedCacheElement( (ICacheElementSerialized) retVal,
this.elementSerializer );
}
}
}
catch ( Exception ex )
{
handleException( ex, "Failed to get [" + key + "] from [" + cacheName + "]", ICacheEventLogger.GET_EVENT );
}
return retVal;
}
/**
* This allows gets to timeout in case of remote server machine shutdown.
* <p>
* @param key
* @return ICacheElement
* @throws IOException
*/
public ICacheElement getUsingPool( final Serializable key )
throws IOException
{
int timeout = getRemoteCacheAttributes().getGetTimeoutMillis();
try
{
FutureResult future = new FutureResult();
Runnable command = future.setter( new Callable()
{
public Object call()
throws IOException
{
return getRemoteCacheService().get( cacheName, key, getListenerId() );
}
} );
// execute using the pool
pool.execute( command );
// used timed get in order to timeout
ICacheElement ice = (ICacheElement) future.timedGet( timeout );
if ( log.isDebugEnabled() )
{
if ( ice == null )
{
log.debug( "nothing found in remote cache" );
}
else
{
log.debug( "found item in remote cache" );
}
}
return ice;
}
catch ( TimeoutException te )
{
log.warn( "TimeoutException, Get Request timed out after " + timeout );
throw new IOException( "Get Request timed out after " + timeout );
}
catch ( InterruptedException ex )
{
log.warn( "InterruptedException, Get Request timed out after " + timeout );
throw new IOException( "Get Request timed out after " + timeout );
}
catch ( InvocationTargetException ex )
{
// assume that this is an IOException thrown by the callable.
log.error( "InvocationTargetException, Assuming an IO exception thrown in the background.", ex );
throw new IOException( "Get Request timed out after " + timeout );
}
}
/**
* Calls get matching on the server. Each entry in the result is unwrapped.
* <p>
* @param pattern
* @return Map
* @throws IOException
*/
public Map processGetMatching( String pattern )
throws IOException
{
Map results = new HashMap();
try
{
Map rawResults = getRemoteCacheService().getMatching( cacheName, pattern, getListenerId() );
// Eventually the instance of will not be necessary.
if ( rawResults != null )
{
Set entrySet = rawResults.entrySet();
Iterator it = entrySet.iterator();
while ( it.hasNext() )
{
Map.Entry entry = (Map.Entry) it.next();
ICacheElement unwrappedResult = null;
if ( entry.getValue() instanceof ICacheElementSerialized )
{
// Never try to deserialize if you are a cluster client. Cluster
// clients are merely intra-remote cache communicators. Remote caches are assumed
// to have no ability to deserialze the objects.
if ( this.getRemoteCacheAttributes().getRemoteType() != IRemoteCacheAttributes.CLUSTER )
{
unwrappedResult = SerializationConversionUtil
.getDeSerializedCacheElement( (ICacheElementSerialized) entry.getValue(),
this.elementSerializer );
}
}
else
{
unwrappedResult = (ICacheElement) entry.getValue();
}
results.put( entry.getKey(), unwrappedResult );
}
}
}
catch ( Exception ex )
{
handleException( ex, "Failed to getMatching [" + pattern + "] from [" + cacheName + "]",
ICacheEventLogger.GET_EVENT );
}
return results;
}
/**
* Gets multiple items from the cache based on the given set of keys.
* <p>
* @param keys
* @return a map of Serializable key to ICacheElement element, or an empty map if there is no
* data in cache for any of these keys
* @throws IOException
*/
protected Map processGetMultiple( Set keys )
throws IOException
{
Map elements = new HashMap();
if ( keys != null && !keys.isEmpty() )
{
Iterator iterator = keys.iterator();
while ( iterator.hasNext() )
{
Serializable key = (Serializable) iterator.next();
ICacheElement element = get( key );
if ( element != null )
{
elements.put( key, element );
}
}
}
return elements;
}
/**
* Synchronously remove from the remote cache; if failed, replace the remote handle with a
* zombie.
* <p>
* @param key
* @return boolean, whether or not the item was removed
* @throws IOException
*/
protected boolean processRemove( Serializable key )
throws IOException
{
if ( !this.getRemoteCacheAttributes().getGetOnly() )
{
if ( log.isDebugEnabled() )
{
log.debug( "remove> key=" + key );
}
try
{
getRemoteCacheService().remove( cacheName, key, getListenerId() );
}
catch ( Exception ex )
{
handleException( ex, "Failed to remove " + key + " from " + cacheName, ICacheEventLogger.REMOVE_EVENT );
}
return true;
}
return false;
}
/**
* Synchronously removeAll from the remote cache; if failed, replace the remote handle with a
* zombie.
* <p>
* @throws IOException
*/
protected void processRemoveAll()
throws IOException
{
if ( !this.getRemoteCacheAttributes().getGetOnly() )
{
try
{
getRemoteCacheService().removeAll( cacheName, getListenerId() );
}
catch ( Exception ex )
{
handleException( ex, "Failed to remove all from " + cacheName, ICacheEventLogger.REMOVEALL_EVENT );
}
}
}
/**
* Serializes the object and then calls update on the remote server with the byte array. The
* byte array is wrapped in a ICacheElementSerialized. This allows the remote server to operate
* without any knowledge of caches classes.
* <p>
* @param ce
* @throws IOException
*/
protected void processUpdate( ICacheElement ce )
throws IOException
{
if ( !getRemoteCacheAttributes().getGetOnly() )
{
ICacheElementSerialized serialized = null;
try
{
if ( log.isDebugEnabled() )
{
log.debug( "sending item to remote server" );
}
// convert so we don't have to know about the object on the
// other end.
serialized = SerializationConversionUtil.getSerializedCacheElement( ce, this.elementSerializer );
remoteCacheService.update( serialized, getListenerId() );
}
catch ( NullPointerException npe )
{
log.error( "npe for ce = " + ce + "ce.attr = " + ce.getElementAttributes(), npe );
}
catch ( Exception ex )
{
// event queue will wait and retry
handleException( ex, "Failed to put [" + ce.getKey() + "] to " + ce.getCacheName(),
ICacheEventLogger.UPDATE_EVENT );
}
}
else
{
if ( log.isDebugEnabled() )
{
log.debug( "get only mode, not sending to remote server" );
}
}
}
/**
* Returns all the keys for a group.
* <p>
* @param groupName
* @return Set
* @throws java.rmi.RemoteException
* @throws IOException
*/
public Set getGroupKeys( String groupName )
throws java.rmi.RemoteException, IOException
{
return getRemoteCacheService().getGroupKeys( cacheName, groupName );
}
/**
* Allows other member of this package to access the listerner. This is mainly needed for
* deregistering a listener.
* <p>
* @return IRemoteCacheListener, the listener for this remote server
*/
public IRemoteCacheListener getListener()
{
return getRemoteCacheListener();
}
/**
* let the remote cache set a listener_id. Since there is only one listener for all the regions
* and every region gets registered? the id shouldn't be set if it isn't zero. If it is we
* assume that it is a reconnect.
* <p>
* @param id The new listenerId value
*/
public void setListenerId( long id )
{
if ( getRemoteCacheListener() != null )
{
try
{
getRemoteCacheListener().setListenerId( id );
if ( log.isDebugEnabled() )
{
log.debug( "set listenerId = " + id );
}
}
catch ( Exception e )
{
log.error( "Problem setting listenerId", e );
}
}
}
/**
* Gets the listenerId attribute of the RemoteCacheListener object
* <p>
* @return The listenerId value
*/
public long getListenerId()
{
if ( getRemoteCacheListener() != null )
{
try
{
if ( log.isDebugEnabled() )
{
log.debug( "get listenerId = " + getRemoteCacheListener().getListenerId() );
}
return getRemoteCacheListener().getListenerId();
}
catch ( Exception e )
{
log.error( "Problem getting listenerId", e );
}
}
return -1;
}
/**
* Returns the current cache size.
* @return The size value
*/
public int getSize()
{
return 0;
}
/**
* Custom exception handling some children. This should be used to initiate failover.
* <p>
* @param ex
* @param msg
* @param eventName
* @throws IOException
*/
protected abstract void handleException( Exception ex, String msg, String eventName )
throws IOException;
/**
* Gets the stats attribute of the RemoteCache object.
* <p>
* @return The stats value
*/
public String getStats()
{
return getStatistics().toString();
}
/**
* @return IStats object
*/
public IStats getStatistics()
{
IStats stats = new Stats();
stats.setTypeName( "AbstractRemoteAuxiliaryCache" );
ArrayList elems = new ArrayList();
IStatElement se = null;
se = new StatElement();
se.setName( "Remote Type" );
se.setData( this.getRemoteCacheAttributes().getRemoteTypeName() + "" );
elems.add( se );
if ( this.getRemoteCacheAttributes().getRemoteType() == IRemoteCacheAttributes.CLUSTER )
{
// something cluster specific
}
// no data gathered here
se = new StatElement();
se.setName( "UsePoolForGet" );
se.setData( "" + usePoolForGet );
elems.add( se );
if ( pool != null )
{
se = new StatElement();
se.setName( "Pool Size" );
se.setData( "" + pool.getPool().getPoolSize() );
elems.add( se );
se = new StatElement();
se.setName( "Maximum Pool Size" );
se.setData( "" + pool.getPool().getMaximumPoolSize() );
elems.add( se );
}
if ( getRemoteCacheService() instanceof ZombieRemoteCacheService )
{
se = new StatElement();
se.setName( "Zombie Queue Size" );
se.setData( "" + ( (ZombieRemoteCacheService) getRemoteCacheService() ).getQueueSize() );
elems.add( se );
}
// get an array and put them in the Stats object
IStatElement[] ses = (IStatElement[]) elems.toArray( new StatElement[0] );
stats.setStatElements( ses );
return stats;
}
/**
* Returns the cache status. An error status indicates the remote connection is not available.
* <p>
* @return The status value
*/
public int getStatus()
{
return getRemoteCacheService() instanceof IZombie ? CacheConstants.STATUS_ERROR : CacheConstants.STATUS_ALIVE;
}
/**
* Replaces the current remote cache service handle with the given handle. If the current remote
* is a Zombie, then it propagates any events that are queued to the restored service.
* <p>
* @param restoredRemote IRemoteCacheService -- the remote server or proxy to the remote server
*/
public void fixCache( IRemoteCacheService restoredRemote )
{
if ( getRemoteCacheService() != null && getRemoteCacheService() instanceof ZombieRemoteCacheService )
{
ZombieRemoteCacheService zombie = (ZombieRemoteCacheService) getRemoteCacheService();
setRemoteCacheService( restoredRemote );
try
{
zombie.propagateEvents( restoredRemote );
}
catch ( Exception e )
{
try
{
handleException( e, "Problem propagating events from Zombie Queue to new Remote Service.",
"fixCache" );
}
catch ( IOException e1 )
{
// swallow, since this is just expected kick back. Handle always throws
}
}
}
else
{
setRemoteCacheService( restoredRemote );
}
return;
}
/**
* Gets the cacheType attribute of the RemoteCache object
* @return The cacheType value
*/
public int getCacheType()
{
return REMOTE_CACHE;
}
/**
* Gets the cacheName attribute of the RemoteCache object.
* <p>
* @return The cacheName value
*/
public String getCacheName()
{
return cacheName;
}
/**
* @param remote the remote to set
*/
protected void setRemoteCacheService( IRemoteCacheService remote )
{
this.remoteCacheService = remote;
}
/**
* @return the remote
*/
protected IRemoteCacheService getRemoteCacheService()
{
return remoteCacheService;
}
/**
* @return Returns the AuxiliaryCacheAttributes.
*/
public AuxiliaryCacheAttributes getAuxiliaryCacheAttributes()
{
return getRemoteCacheAttributes();
}
/**
* @param remoteCacheAttributes the remoteCacheAttributes to set
*/
protected void setRemoteCacheAttributes( IRemoteCacheAttributes remoteCacheAttributes )
{
this.remoteCacheAttributes = remoteCacheAttributes;
}
/**
* @return the remoteCacheAttributes
*/
protected IRemoteCacheAttributes getRemoteCacheAttributes()
{
return remoteCacheAttributes;
}
/**
* @param remoteCacheListener the remoteCacheListener to set
*/
protected void setRemoteCacheListener( IRemoteCacheListener remoteCacheListener )
{
this.remoteCacheListener = remoteCacheListener;
}
/**
* @return the remoteCacheListener
*/
protected IRemoteCacheListener getRemoteCacheListener()
{
return remoteCacheListener;
}
}