Module lettuce.core

Package io.lettuce.core.support

Class ConnectionPoolSupport

java.lang.Object

io.lettuce.core.support.ConnectionPoolSupport

public abstract class ConnectionPoolSupport
extends Object

Connection pool support for GenericObjectPool and SoftReferenceObjectPool. Connection pool creation requires a Supplier that creates Redis connections. The pool can allocate either wrapped or direct connections.

• Wrapped instances will return the connection back to the pool when called StatefulConnection.close().
• Regular connections need to be returned to the pool with GenericObjectPool.returnObject(Object)

Lettuce connections are designed to be thread-safe so one connection can be shared amongst multiple threads and Lettuce connections auto-reconnect by default. Connection pooling with Lettuce can be required when you're invoking Redis operations in multiple threads and you use

• blocking commands such as BLPOP.
• transactions BLPOP.
• command batching.

Transactions and command batching affect connection state. Blocking commands won't propagate queued commands to Redis until the blocking command is completed.

Example

 // application initialization
 RedisClusterClient clusterClient = RedisClusterClient.create(RedisURI.create(host, port));
 GenericObjectPool<StatefulRedisClusterConnection<String, String>> pool = ConnectionPoolSupport
         .createGenericObjectPool(() -> clusterClient.connect(), new GenericObjectPoolConfig());

 // executing work
 try (StatefulRedisClusterConnection<String, String> connection = pool.borrowObject()) {
     // perform some work
 }

 // terminating
 pool.close();
 clusterClient.shutdown();
 

Since:

4.3

Author:

Mark Paluch

Method Summary

Modifier and Type	Method	Description
static <T extends StatefulConnection<?, ?>> GenericObjectPool<T>	createGenericObjectPool(Supplier<T> connectionSupplier, GenericObjectPoolConfig<T> config)	Creates a new GenericObjectPool using the Supplier.
static <T extends StatefulConnection<?, ?>> GenericObjectPool<T>	createGenericObjectPool(Supplier<T> connectionSupplier, GenericObjectPoolConfig<T> config, boolean wrapConnections)	Creates a new GenericObjectPool using the Supplier.
static <T extends StatefulConnection<?, ?>> SoftReferenceObjectPool<T>	createSoftReferenceObjectPool(Supplier<T> connectionSupplier)	Creates a new SoftReferenceObjectPool using the Supplier.
static <T extends StatefulConnection<?, ?>> SoftReferenceObjectPool<T>	createSoftReferenceObjectPool(Supplier<T> connectionSupplier, boolean wrapConnections)	Creates a new SoftReferenceObjectPool using the Supplier.

Methods inherited from class java.lang.Object

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

Method Details

createGenericObjectPool

public static <T extends StatefulConnection<?,
?>>
GenericObjectPool<T> createGenericObjectPool(Supplier<T> connectionSupplier,
GenericObjectPoolConfig<T> config)

Creates a new GenericObjectPool using the Supplier. Allocated instances are wrapped and must not be returned with ObjectPool.returnObject(Object).

Type Parameters:

T - connection type.

Parameters:

connectionSupplier - must not be null.

config - must not be null.

Returns:

the connection pool.

createGenericObjectPool

public static <T extends StatefulConnection<?,
?>>
GenericObjectPool<T> createGenericObjectPool(Supplier<T> connectionSupplier,
GenericObjectPoolConfig<T> config,
boolean wrapConnections)

Creates a new GenericObjectPool using the Supplier.

Type Parameters:

T - connection type.

Parameters:

connectionSupplier - must not be null.

config - must not be null.

wrapConnections - false to return direct connections that need to be returned to the pool using ObjectPool.returnObject(Object). true to return wrapped connection that are returned to the pool when invoking StatefulConnection.close().

Returns:

the connection pool.

createSoftReferenceObjectPool

public static <T extends StatefulConnection<?,
?>>
SoftReferenceObjectPool<T> createSoftReferenceObjectPool(Supplier<T> connectionSupplier)

Creates a new SoftReferenceObjectPool using the Supplier. Allocated instances are wrapped and must not be returned with ObjectPool.returnObject(Object).

Type Parameters:

T - connection type.

Parameters:

connectionSupplier - must not be null.

Returns:

the connection pool.

createSoftReferenceObjectPool

public static <T extends StatefulConnection<?,
?>>
SoftReferenceObjectPool<T> createSoftReferenceObjectPool(Supplier<T> connectionSupplier,
boolean wrapConnections)

Creates a new SoftReferenceObjectPool using the Supplier.

Type Parameters:

T - connection type.

Parameters:

connectionSupplier - must not be null.

wrapConnections - false to return direct connections that need to be returned to the pool using ObjectPool.returnObject(Object). true to return wrapped connection that are returned to the pool when invoking StatefulConnection.close().

Returns:

the connection pool.