org.apache.jcs.auxiliary.remote.server
Class RemoteCacheServer

java.lang.Object
  java.rmi.server.RemoteObject
      java.rmi.server.RemoteServer
          java.rmi.server.UnicastRemoteObject
              org.apache.jcs.auxiliary.remote.server.RemoteCacheServer

All Implemented Interfaces:

ICacheObserver, ICacheService, ICacheServiceAdmin, IRemoteCacheObserver, IRemoteCacheService, IRemoteCacheServiceAdmin, java.rmi.Remote, java.io.Serializable, java.rmi.server.Unreferenced

public class RemoteCacheServer

extends java.rmi.server.UnicastRemoteObject

implements IRemoteCacheService, IRemoteCacheObserver, IRemoteCacheServiceAdmin, java.rmi.server.Unreferenced

This class provides remote cache services. The remote cache server propagates events from local caches to other local caches. It can also store cached data, making it available to new clients. Remote cache servers can be clustered. If the cache used by this remote cache is configured to use a remote cache of type cluster, the two remote caches will communicate with each other. Remote and put requests can be sent from one remote to another. If they are configured to broadcast such event to their client, then remove an puts can be sent to all locals in the cluster. However, get requests are not made between clustered servers. You can setup several clients to use one remote server and several to use another. The get locad will be distributed between the two servers. Since caches are usually high get and low put, this should allow you to scale.

See Also:

Serialized Form

Field Summary

protected IRemoteCacheServerAttributes	rcsa Description of the Field
protected static boolean	timing timing -- if we should record operation times.

Fields inherited from class java.rmi.server.RemoteObject

ref

Constructor Summary

protected

RemoteCacheServer(IRemoteCacheServerAttributes rcsa) Constructor for the RemoteCacheServer object

Method Summary

void	addCacheListener(ICacheListener listener) Subscribes to all remote caches.
void	addCacheListener(java.lang.String cacheName, ICacheListener listener) Subscribes to the specified remote cache.
protected CompositeCacheManager	createCacheManager(java.lang.String prop) Subclass can overrdie this method to create the specific cache manager.
void	dispose(java.lang.String cacheName) Frees the specified remote cache.
void	dispose(java.lang.String cacheName, long requesterId) Frees the specified remote cache.
ICacheElement	get(java.lang.String cacheName, java.io.Serializable key) Returns a cache value from the specified remote cache; or null if the cache or key does not exist.
java.util.Set	getGroupKeys(java.lang.String cacheName, java.lang.String group) Gets the set of keys of objects currently in the group.
java.lang.String	getStats() Gets the stats attribute of the RemoteCacheServer object
protected void	init(java.lang.String prop) Initialize the RMI Cache Server from a proeprties file.
void	put(ICacheElement item) Puts a cache bean to the remote cache and notifies all listeners which have a different listener id than the originating host; are currently subscribed to the related cache.
void	release() Frees all remote caches.
void	remove(java.lang.String cacheName, java.io.Serializable key) Removes the given key from the specified remote cache.
void	remove(java.lang.String cacheName, java.io.Serializable key, long requesterId) Remove the key from the cache region and don't tell the source listener about it.
void	removeAll(java.lang.String cacheName) Remove all keys from the sepcified remote cache.
void	removeAll(java.lang.String cacheName, long requesterId) Remove all keys from the sepcified remote cache.
void	removeCacheListener(ICacheListener listener) Unsubscribes from all remote caches.
void	removeCacheListener(java.lang.String cacheName, ICacheListener listener) Unsubscribes from the specified cache.
void	removeCacheListener(java.lang.String cacheName, long listenerId) Unsibscribe this region.
void	shutdown() Shuts down the remote server.
void	shutdown(java.lang.String host, int port) Shuts down a server at a particular host and port.
void	unreferenced() Called by the RMI runtime sometime after the runtime determines that the reference list, the list of clients referencing the remote object, becomes empty.
void	update(ICacheElement item) Puts a cache item to the cache.
void	update(ICacheElement item, long requesterId) An update can come from either a local cache's remote auxiliary, or it can come from a remote server.

Methods inherited from class java.rmi.server.UnicastRemoteObject

clone, exportObject, exportObject, exportObject, unexportObject

Methods inherited from class java.rmi.server.RemoteServer

getClientHost, getLog, setLog

Methods inherited from class java.rmi.server.RemoteObject

equals, getRef, hashCode, toString, toStub

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

timing

protected static final boolean timing

timing -- if we should record operation times.

See Also:

Constant Field Values

rcsa

protected IRemoteCacheServerAttributes rcsa

Description of the Field

Constructor Detail

RemoteCacheServer

protected RemoteCacheServer(IRemoteCacheServerAttributes rcsa)
                     throws java.io.IOException,
                            java.rmi.NotBoundException

Constructor for the RemoteCacheServer object

Parameters:

rcsa -

Throws:

java.io.IOException

java.rmi.NotBoundException

Method Detail

init

protected void init(java.lang.String prop)
             throws java.io.IOException,
                    java.rmi.NotBoundException

Initialize the RMI Cache Server from a proeprties file.

Parameters:

prop -

Throws:

java.io.IOException

java.rmi.NotBoundException

createCacheManager

protected CompositeCacheManager createCacheManager(java.lang.String prop)

Subclass can overrdie this method to create the specific cache manager.

Parameters:

prop - The anem of the configuration file.

Returns:

The cache hub configured with this configuration file.

put

public void put(ICacheElement item)
         throws java.io.IOException

Puts a cache bean to the remote cache and notifies all listeners which

1. have a different listener id than the originating host;
2. are currently subscribed to the related cache.

Parameters:

item -

Throws:

java.io.IOException

update

public void update(ICacheElement item)
            throws java.io.IOException

Description copied from interface: ICacheService

Puts a cache item to the cache.

Specified by:

update in interface ICacheService

Parameters:

item -

Throws:

java.io.IOException

update

public void update(ICacheElement item,
                   long requesterId)
            throws java.io.IOException

An update can come from either a local cache's remote auxiliary, or it can come from a remote server. A remote server is considered a a source of type cluster.

If the update came from a cluster, then we should tell the cache manager that this was a remote put. This way, any lateral and remote auxiliaries configured for the region will not be updated. This is basically how a remote listener works when plugged into a local cache.

If the cluster is configured to keep local cluster consistency, then all listeners will be updated. This allows cluster server A to update cluster server B and then B to update its clients if it is told to keep local cluster consistency. Otherwise, server A will update server B and B will not tell its clients. If you cluster using lateral caches for instance, this is how it will work. Updates to a cluster node, will never get to the leavess. The remote cluster, with local cluster consistency, allows you to update leaves. This basically allows you to have a failover remote server.

Since currently a cluster will not try to get from other cluster servers, you can scale a bit with a cluster configuration. Puts and removes will be broadcasted to all clients, but the get load on a remote server can be reduced.

Specified by:

update in interface IRemoteCacheService

Parameters:

item -

requesterId -

Throws:

java.io.IOException

get

public ICacheElement get(java.lang.String cacheName,
                         java.io.Serializable key)
                  throws java.io.IOException

Returns a cache value from the specified remote cache; or null if the cache or key does not exist.

Specified by:

get in interface ICacheService

Parameters:

cacheName -

key -

Returns:

Throws:

java.io.IOException

getGroupKeys

public java.util.Set getGroupKeys(java.lang.String cacheName,
                                  java.lang.String group)

Gets the set of keys of objects currently in the group.

Specified by:

getGroupKeys in interface IRemoteCacheService

Parameters:

cacheName -

group -

Returns:

A Set of group keys

remove

public void remove(java.lang.String cacheName,
                   java.io.Serializable key)
            throws java.io.IOException

Removes the given key from the specified remote cache. Defaults the listener id to 0.

Specified by:

remove in interface ICacheService

Parameters:

cacheName -

key -

Throws:

java.io.IOException

remove

public void remove(java.lang.String cacheName,
                   java.io.Serializable key,
                   long requesterId)
            throws java.io.IOException

Remove the key from the cache region and don't tell the source listener about it.

Specified by:

remove in interface IRemoteCacheService

Parameters:

cacheName -

key -

requesterId -

Throws:

java.io.IOException

removeAll

public void removeAll(java.lang.String cacheName)
               throws java.io.IOException

Remove all keys from the sepcified remote cache.

Specified by:

removeAll in interface ICacheService

Parameters:

cacheName -

Throws:

java.io.IOException

removeAll

public void removeAll(java.lang.String cacheName,
                      long requesterId)
               throws java.io.IOException

Remove all keys from the sepcified remote cache.

Specified by:

removeAll in interface IRemoteCacheService

Parameters:

cacheName -

requesterId -

Throws:

java.io.IOException

dispose

public void dispose(java.lang.String cacheName)
             throws java.io.IOException

Frees the specified remote cache.

Specified by:

dispose in interface ICacheService

Parameters:

cacheName -

Throws:

java.io.IOException

dispose

public void dispose(java.lang.String cacheName,
                    long requesterId)
             throws java.io.IOException

Frees the specified remote cache.

Parameters:

cacheName -

requesterId -

Throws:

java.io.IOException

release

public void release()
             throws java.io.IOException

Frees all remote caches.

Specified by:

release in interface ICacheService

Throws:

java.io.IOException

addCacheListener

public void addCacheListener(java.lang.String cacheName,
                             ICacheListener listener)
                      throws java.io.IOException

Subscribes to the specified remote cache.

Specified by:

addCacheListener in interface ICacheObserver

Parameters:

cacheName - the specified remote cache.

listener - object to notify for cache changes. must be synchronized since there are remote calls involved.

Throws:

java.io.IOException

addCacheListener

public void addCacheListener(ICacheListener listener)
                      throws java.io.IOException

Subscribes to all remote caches.

Specified by:

addCacheListener in interface ICacheObserver

Parameters:

listener - The feature to be added to the CacheListener attribute

Throws:

java.io.IOException

removeCacheListener

public void removeCacheListener(java.lang.String cacheName,
                                ICacheListener listener)
                         throws java.io.IOException

Description copied from interface: ICacheObserver

Unsubscribes from the specified cache.

Specified by:

removeCacheListener in interface ICacheObserver

Parameters:

cacheName -

listener - existing subscriber.

Throws:

java.io.IOException

removeCacheListener

public void removeCacheListener(java.lang.String cacheName,
                                long listenerId)
                         throws java.io.IOException

Unsibscribe this region.

Parameters:

cacheName -

listenerId -

Throws:

java.io.IOException

removeCacheListener

public void removeCacheListener(ICacheListener listener)
                         throws java.io.IOException

Unsubscribes from all remote caches.

Specified by:

removeCacheListener in interface ICacheObserver

Parameters:

listener -

Throws:

java.io.IOException

shutdown

public void shutdown()
              throws java.io.IOException

Shuts down the remote server.

Specified by:

shutdown in interface ICacheServiceAdmin

Throws:

java.io.IOException

shutdown

public void shutdown(java.lang.String host,
                     int port)
              throws java.io.IOException

Shuts down a server at a particular host and port.

Specified by:

shutdown in interface ICacheServiceAdmin

Parameters:

host -

port -

Throws:

java.io.IOException

unreferenced

public void unreferenced()

Called by the RMI runtime sometime after the runtime determines that the reference list, the list of clients referencing the remote object, becomes empty.

Specified by:

unreferenced in interface java.rmi.server.Unreferenced

getStats

public java.lang.String getStats()
                          throws java.io.IOException

Gets the stats attribute of the RemoteCacheServer object

Specified by:

getStats in interface ICacheServiceAdmin

Returns:

The stats value

Throws:

java.io.IOException