io.lettuce.core.support

Class AsyncConnectionPoolSupport

java.lang.Object

io.lettuce.core.support.AsyncConnectionPoolSupport

public abstract class AsyncConnectionPoolSupport
extends Object

Asynchronous connection pool support for BoundedAsyncPool. Connection pool creation requires a Supplier that connects asynchronously to Redis. The pool can allocate either wrapped or direct connections.

• Wrapped instances will return the connection back to the pool when called StatefulConnection.close()/ StatefulConnection.closeAsync().
• Regular connections need to be returned to the pool with AsyncPool.release(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));
 AsyncPool<StatefulRedisConnection<String, String>> pool = AsyncConnectionPoolSupport.createBoundedObjectPool(
         () -> clusterClient.connectAsync(), BoundedPoolConfig.create());

 // executing work
 CompletableFuture<String> pingResponse = pool.acquire().thenCompose(c -> {

     return c.async().ping().whenComplete((s, throwable) -> pool.release(c));
 });

 // terminating
 CompletableFuture<Void> poolClose = pool.closeAsync();

 // after poolClose completes:
 CompletableFuture<Void> closeFuture = clusterClient.shutdown();
 

Since:

5.1

Author:

Mark Paluch

Method Summary

Modifier and Type	Method and Description
static <T extends StatefulConnection<?,?>> BoundedAsyncPool<T>	createBoundedObjectPool(Supplier<CompletionStage<T>> connectionSupplier, BoundedPoolConfig config) Creates a new BoundedAsyncPool using the Supplier.
static <T extends StatefulConnection<?,?>> BoundedAsyncPool<T>	createBoundedObjectPool(Supplier<CompletionStage<T>> connectionSupplier, BoundedPoolConfig config, boolean wrapConnections) Creates a new BoundedAsyncPool using the Supplier.

Methods inherited from class java.lang.Object

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

Method Detail

createBoundedObjectPool

public static <T extends StatefulConnection<?,?>> BoundedAsyncPool<T> createBoundedObjectPool(Supplier<CompletionStage<T>> connectionSupplier,
                                                                                              BoundedPoolConfig config)

Creates a new BoundedAsyncPool using the Supplier. Allocated instances are wrapped and must not be returned with AsyncPool.release(Object).

Type Parameters:

T - connection type.

Parameters:

connectionSupplier - must not be null.

config - must not be null.

Returns:

the connection pool.

createBoundedObjectPool

public static <T extends StatefulConnection<?,?>> BoundedAsyncPool<T> createBoundedObjectPool(Supplier<CompletionStage<T>> connectionSupplier,
                                                                                              BoundedPoolConfig config,
                                                                                              boolean wrapConnections)

Creates a new BoundedAsyncPool 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 AsyncPool.release(Object). true to return wrapped connection that are returned to the pool when invoking StatefulConnection.close()/StatefulConnection.closeAsync().

Returns:

the connection pool.