org.bbottema.clusteredobjectpool.core

Class ResourceClusters<ClusterKey,PoolKey,T>

java.lang.Object

org.bbottema.clusteredobjectpool.core.ResourceClusters<ClusterKey,PoolKey,T>

Type Parameters:

ClusterKey - Anything, to identify a group of resources pools. For example String if your cluster * keys are going to be "cluster1", "cluster2" etc. Or UUID for uuid's (or again String for UUID.toString()).

PoolKey - The resource for which multiple objects will be created in a generic-object-pool object pool.
For example a javax.mail Session object for which multiple Transport connections can be created.

T - The resulting PoolableObject object that the allocators will create for the pool key.
Continuing the example above, if the PoolKey is Session, then T could be Transport.

public class ResourceClusters<ClusterKey,PoolKey,T>
extends Object

Collection of clusters, each containing a number of (generic-object-pool) resource pools. Relies on the native generic-object-pool behavior for auto-replenishing and pre-allocating resources (so always allocates / fills up to max pool size).

Can be used to configure high performance clusters of expensive resources that have a time-to-live.

Example use case:
Say you have two different mail clusters, each with several servers and each server able to handle multiple concurrent SMTP connections.
The two cluster keys to the clusters, where each server is accessed round robin, and the objects in the respective cluster-pool are concurrent open connections to the same mail server.

1. Cluster 1, serverA, serverB, serverC
2. Cluster 2, serverD, serverE

Constructor Summary

Constructors

Constructor and Description
ResourceClusters(ClusterConfig<PoolKey,T> clusterConfig)

Method Summary

Modifier and Type	Method and Description
@Nullable org.bbottema.genericobjectpool.PoolableObject<T>	claimResourceFromCluster(ClusterKey clusterKey) Tries to claim the next resources from a pool in the given cluster.
@Nullable org.bbottema.genericobjectpool.PoolableObject<T>	claimResourceFromPool(ResourceKey<ClusterKey,PoolKey> key) Tries to claim the next resources from the pool in the given cluster.
int	countLiveResources()
boolean	isPoolRegistered(@NotNull ResourceKey<ClusterKey,PoolKey> key)
void	registerResourcePool(ResourceKey<ClusterKey,PoolKey> key) Delegates to registerResourcePool(ResourceKey, ExpirationPolicy, int, int), using the global defaults for expiration policy, max pool size and sizing mode.
void	registerResourcePool(@NotNull ResourceKey<ClusterKey,PoolKey> key, @NotNull org.bbottema.genericobjectpool.ExpirationPolicy<T> expirationPolicy, int corePoolSize, int maxPoolSize) Registers a new pool for the given cluster.
Future<?>	shutDown() Delegates to shutdownPool(Object) with empty pool key.
Future<Void>	shutdownPool(PoolKey key) Tells all generic-object-pool pools [for the specified pool key] to shutdown and removes them from the clusters.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ResourceClusters

public ResourceClusters(ClusterConfig<PoolKey,T> clusterConfig)

Method Detail

registerResourcePool

public void registerResourcePool(ResourceKey<ClusterKey,PoolKey> key)

Delegates to registerResourcePool(ResourceKey, ExpirationPolicy, int, int), using the global defaults for expiration policy, max pool size and sizing mode.

registerResourcePool

public void registerResourcePool(@NotNull
                                 @NotNull ResourceKey<ClusterKey,PoolKey> key,
                                 @NotNull
                                 @NotNull org.bbottema.genericobjectpool.ExpirationPolicy<T> expirationPolicy,
                                 int corePoolSize,
                                 int maxPoolSize)
                          throws IllegalArgumentException

Registers a new pool for the given cluster. If the cluster is new as well, it will also be created. The new pool is backed by a GenericObjectPool.

Throws:

IllegalArgumentException - if the pool already exists in the specified cluster.

isPoolRegistered

public boolean isPoolRegistered(@NotNull
                                @NotNull ResourceKey<ClusterKey,PoolKey> key)

Returns:

If a cluster and pool combination is registered as a known pool.

claimResourceFromCluster

@Nullable
public @Nullable org.bbottema.genericobjectpool.PoolableObject<T> claimResourceFromCluster(ClusterKey clusterKey)
                                                                                              throws InterruptedException

Tries to claim the next resources from a pool in the given cluster. This cluster is assumed to have been populated with at least one pool already (because they can't be added without pool key).

Either preregister pools using claimResourceFromPool(ResourceKey) or dynamically add pools on-the-fly using registerResourcePool(ResourceKey) or registerResourcePool(ResourceKey, ExpirationPolicy, int, int).

Throws:

InterruptedException

claimResourceFromPool

@Nullable
public @Nullable org.bbottema.genericobjectpool.PoolableObject<T> claimResourceFromPool(ResourceKey<ClusterKey,PoolKey> key)
                                                                                           throws InterruptedException

Tries to claim the next resources from the pool in the given cluster. If the cluster key is unknown, a new cluster is created with one resources pool to draw from. If the pool key is unknown, a new pool to draw from is created for that key.

Throws:

InterruptedException

countLiveResources

public int countLiveResources()

Returns:

The number of resources currently allocated and ready to be used.

shutDown

public Future<?> shutDown()

Delegates to shutdownPool(Object) with empty pool key.

shutdownPool

public Future<Void> shutdownPool(@Nullable
                                 PoolKey key)

Tells all generic-object-pool pools [for the specified pool key] to shutdown and removes them from the clusters.

After calling this, the cluster is ready for more work as if it was just created.