* The cluster name needs to be set before any communication is possible. This can be done using the
* system property
* {@link #PROP_CLUSTER_NAME_PREFIX -Dalfresco.cluster-name-prefix}=MyCluster
* or by declaring a bean
*
*
* The channels provided to the callers will be proxies to underlying channels that will be hot-swappable.
* This means that the client code can continue to use the channel references while the actual
* implementation can be switched in and out as required.
*
* @see #PROP_CLUSTER_NAME_PREFIX
*
* @author Derek Hulley
* @since 2.1.3
*/
public class AlfrescoJGroupsChannelFactory extends AbstractLifecycleBean
{
/** A catch-all for unknown application regions. */
public static final String APP_REGION_DEFAULT = "DEFAULT";
/** The application region used by the EHCache heartbeat implementation over JGroups. */
public static final String APP_REGION_EHCACHE_HEARTBEAT = "EHCACHE_HEARTBEAT";
/** The UDP protocol stack (default) */
public static final String PROTOCOL_STACK_UDP = "UDP";
/** The TCP protocol stack */
public static final String PROTOCOL_STACK_TCP = "TCP";
public static final String PROP_CLUSTER_NAME_PREFIX = "alfresco.cluster-name-prefix";
public static final String CUSTOM_CONFIGURATION_FILE = "classpath:alfresco/extension/jgroups-custom.xml";
public static final String DEFAULT_CONFIGURATION_FILE = "classpath:alfresco/jgroups-default.xml";
private static Log logger = LogFactory.getLog(AlfrescoJGroupsChannelFactory.class);
// Synchronization locks
private static ReadLock readLock;
private static WriteLock writeLock;
// Values that are modified by the bean implementation
private static String clusterNamePrefix;
private static URL configUrl;
private static Map
* The application region is used to determine the protocol stack to apply.
*
* This method returns a dummy channel if no cluster name has been provided.
*
* @param appRegion the application region identifier.
* @return Returns a channel
*/
public static Channel getChannel(String appRegion)
{
readLock.lock();
try
{
ChannelProxy channelProxy = channels.get(appRegion);
if (channelProxy != null)
{
// This will do
return channelProxy;
}
}
finally
{
readLock.unlock();
}
// Being here means that there is no channel yet
// Go write
writeLock.lock();
try
{
// Double check
ChannelProxy channelProxy = channels.get(appRegion);
if (channelProxy != null)
{
// This will do
return channelProxy;
}
// Get the channel
Channel channel = getChannelInternal(appRegion);
// Proxy the channel
channelProxy = new ChannelProxy(channel);
// Store the channel to the map
channels.put(appRegion, channelProxy);
// Done
return channelProxy;
}
finally
{
writeLock.unlock();
}
}
/**
* Creates a channel for the given cluster. The application region is used
* to determine the protocol stack to apply.
*
* @param appRegion the application region identifier.
* @return Returns a channel
*/
/* All calls to this are ultimately wrapped in the writeLock. */
private static /*synchronized*/ Channel getChannelInternal(String appRegion)
{
Channel channel;
// If there is no cluster defined (yet) then we define a dummy channel
if (AlfrescoJGroupsChannelFactory.clusterNamePrefix == null)
{
try
{
channel = new DummyJChannel();
}
catch (Throwable e)
{
throw new AlfrescoRuntimeException(
"Failed to create dummy JGroups channel: \n" +
" Cluster prefix: " + clusterNamePrefix + "\n" +
" App region: " + appRegion,
e);
}
}
else // Create real channel
{
JChannelFactory channelFactory = getChannelFactory();
// Get the protocol stack to use
String stack = stacksByAppRegion.get(appRegion);
if (!PropertyCheck.isValidPropertyString(stack))
{
stack = stacksByAppRegion.get(AlfrescoJGroupsChannelFactory.APP_REGION_DEFAULT);
}
if (stack == null)
{
throw new AlfrescoRuntimeException(
"No protocol stack was found for application region: \n" +
" Cluster prefix: " + clusterNamePrefix + "\n" +
" App region: " + appRegion + "\n" +
" Regions defined: " + stacksByAppRegion);
}
try
{
// Get the stack config from the factory (we are not using MUX)
String config = channelFactory.getConfig(stack);
channel = new JChannel(config);
}
catch (Throwable e)
{
throw new AlfrescoRuntimeException(
"Failed to create JGroups channel: \n" +
" Cluster prefix: " + clusterNamePrefix + "\n" +
" App region: " + appRegion + "\n" +
" Protocol stack: " + stack + "\n" +
" Configuration URL: " + AlfrescoJGroupsChannelFactory.configUrl,
e);
}
}
// Initialise the channel
try
{
String clusterName = clusterNamePrefix + ":" + appRegion;
// Set reconnect property
channel.setOpt(Channel.AUTO_RECONNECT, Boolean.TRUE);
// Don't accept messages from self
channel.setOpt(Channel.LOCAL, Boolean.FALSE);
// No state transfer
channel.setOpt(Channel.AUTO_GETSTATE, Boolean.FALSE);
// Connect
channel.connect(clusterName, null, null, 5000L);
// Done
if (logger.isDebugEnabled())
{
logger.debug("\n" +
"Created JGroups channel: \n" +
" Cluster prefix: " + clusterNamePrefix + "\n" +
" App region: " + appRegion + "\n" +
" Channel: " + channel + "\n" +
" Configuration URL: " + AlfrescoJGroupsChannelFactory.configUrl);
}
}
catch (Throwable e)
{
throw new AlfrescoRuntimeException(
"Failed to initialise JGroups channel: \n" +
" Cluster prefix: " + clusterNamePrefix + "\n" +
" App region: " + appRegion + "\n" +
" Channel: " + channel + "\n" +
" Configuration URL: " + AlfrescoJGroupsChannelFactory.configUrl,
e);
}
return channel;
}
/**
* Builds and initializes a JChannelFactory
*/
/* All calls to this are ultimately wrapped in the writeLock. */
private static /*synchronized*/ JChannelFactory getChannelFactory()
{
if (AlfrescoJGroupsChannelFactory.channelFactory != null)
{
return AlfrescoJGroupsChannelFactory.channelFactory;
}
// Set the config location to use
if (AlfrescoJGroupsChannelFactory.configUrl == null)
{
// This was not set by the bean so set it using the default mechanism
try
{
AlfrescoJGroupsChannelFactory.configUrl = ResourceUtils.getURL(CUSTOM_CONFIGURATION_FILE);
}
catch (FileNotFoundException e)
{
// try the alfresco default
try
{
AlfrescoJGroupsChannelFactory.configUrl = ResourceUtils.getURL(DEFAULT_CONFIGURATION_FILE);
}
catch (FileNotFoundException ee)
{
throw new AlfrescoRuntimeException("Missing default JGroups config: " + DEFAULT_CONFIGURATION_FILE);
}
}
}
try
{
// Construct factory
AlfrescoJGroupsChannelFactory.channelFactory = new JChannelFactory();
channelFactory.setMultiplexerConfig(AlfrescoJGroupsChannelFactory.configUrl);
}
catch (Throwable e)
{
throw new AlfrescoRuntimeException(
"Failed to construct JChannelFactory using config: " + AlfrescoJGroupsChannelFactory.configUrl,
e);
}
// done
if (logger.isInfoEnabled())
{
logger.info("\n" +
"Created JChannelFactory: \n" +
" Cluster Name: " + (AlfrescoJGroupsChannelFactory.clusterNamePrefix == null ? "" : AlfrescoJGroupsChannelFactory.clusterNamePrefix) + "\n" +
" Stack Mapping: " + AlfrescoJGroupsChannelFactory.stacksByAppRegion + "\n" +
" Configuration: " + AlfrescoJGroupsChannelFactory.configUrl);
}
return AlfrescoJGroupsChannelFactory.channelFactory;
}
/**
* Throw away all calculated values and rebuild. This means that the channel factory will
* be reconstructed from scratch. All the channels are reconstructed - but this will not
* affect any references to channels held outside this class as the values returned are proxies
* on top of hot swappable implementations.
*/
/* All calls to this are ultimately wrapped in the writeLock. */
private static /*synchronized*/ void rebuildChannels()
{
// First throw away the channel factory. It will be fetched lazily.
AlfrescoJGroupsChannelFactory.channelFactory = null;
// Reprocess all the application regions with the new data
for (Map.Entry
* Note that the old delegate is not closed or shutdown.
*
* @param the new delegate
* @return the old, disconnected delegate
*/
public Channel swap(Channel channel)
{
// Remove the listeners from the old channel
delegate.setReceiver(null);
for (ChannelListener delegateChannelListener : delegateChannelListeners)
{
delegate.removeChannelListener(delegateChannelListener);
}
delegate.setUpHandler(null);
Channel oldDelegage = delegate;
// Assign the new delegate and carry the listeners over
delegate = channel;
delegate.setReceiver(delegateReceiver);
for (ChannelListener delegateChannelListener : delegateChannelListeners)
{
delegate.addChannelListener(delegateChannelListener);
}
delegate.setUpHandler(delegateUpHandler);
// Done
return oldDelegage;
}
@Override
protected Log getLog()
{
throw new UnsupportedOperationException();
}
public void setReceiver(Receiver r)
{
delegateReceiver = r;
delegate.setReceiver(r);
}
public void addChannelListener(ChannelListener listener)
{
if (listener == null)
{
return;
}
delegateChannelListeners.add(listener);
delegate.addChannelListener(listener);
}
public void removeChannelListener(ChannelListener listener)
{
if (listener != null)
{
delegateChannelListeners.remove(listener);
}
delegate.removeChannelListener(listener);
}
public void clearChannelListeners()
{
delegateChannelListeners.clear();
delegate.clearChannelListeners();
}
public void setUpHandler(UpHandler up_handler)
{
delegateUpHandler = up_handler;
delegate.setUpHandler(up_handler);
}
public void blockOk()
{
delegate.blockOk();
}
public void close()
{
delegate.close();
}
public void connect(String cluster_name, Address target, String state_id, long timeout) throws ChannelException
{
delegate.connect(cluster_name, target, state_id, timeout);
}
public void connect(String cluster_name) throws ChannelException
{
delegate.connect(cluster_name);
}
public void disconnect()
{
delegate.disconnect();
}
public void down(Event evt)
{
delegate.down(evt);
}
public Object downcall(Event evt)
{
return delegate.downcall(evt);
}
public String dumpQueue()
{
return delegate.dumpQueue();
}
@SuppressWarnings("unchecked")
public Map dumpStats()
{
return delegate.dumpStats();
}
public boolean equals(Object obj)
{
return delegate.equals(obj);
}
public boolean flushSupported()
{
return delegate.flushSupported();
}
@SuppressWarnings("unchecked")
public boolean getAllStates(Vector targets, long timeout) throws ChannelNotConnectedException, ChannelClosedException
{
return delegate.getAllStates(targets, timeout);
}
public String getChannelName()
{
return delegate.getChannelName();
}
public String getClusterName()
{
return delegate.getClusterName();
}
public Map
* clusterNamePrefix:appRegion
*
* If no cluster name prefix is declared, the cluster is effectively disabled.
*
* @param clusterNamePrefix a prefix to append to the cluster names used
*/
public static void changeClusterNamePrefix(String clusterNamePrefix)
{
writeLock.lock();
try
{
if (!PropertyCheck.isValidPropertyString(clusterNamePrefix))
{
// Clear everything out
AlfrescoJGroupsChannelFactory.clusterNamePrefix = null;
}
else
{
AlfrescoJGroupsChannelFactory.clusterNamePrefix = clusterNamePrefix;
}
}
finally
{
writeLock.unlock();
}
}
/**
* Configure a mapping between the application regions and the available JGroup protocol stacks.
* The map must contain a mapping for application region 'DEFAULT'.
*
* @param protocolMap a mapping from application region (keys) to protocol stacks (values)
*/
public static void changeProtocolStackMapping(Map