Package io.lettuce.core.dynamic.batch

Annotation Type BatchSize

@Retention(RUNTIME)
@Target(TYPE)
@Documented
public @interface BatchSize

Redis command method annotation declaring a command interface to use batching with a specified batchSize.

Usage:

 @BatchSize(50)
 public interface MyCommands extends Commands {

   public void set(String key, String value);

   public RedisFuture<String> get(String key)
 }
 

Command batching executes commands in a deferred nature. This also means that at the time of invocation no result is available. Batching can be only used with synchronous methods without a return value (void) or asynchronous methods returning a RedisFuture. Reactive command batching is not supported because reactive executed commands maintain an own subscription lifecycle that is decoupled from command method batching.

Command methods participating in batching share a single batch queue. All method invocations are queued until reaching the batch size. Command batching can be also specified using dynamic batching by providing a CommandBatching parameter on each command invocation. CommandBatching parameters have precedence over BatchSize and can be used to enqueue commands or force batch flushing of commands.

Alternatively, a command interface can implement BatchExecutor to BatchExecutor.flush() commands before the batch size is reached. Commands remain in a batch queue until the batch size is reached or the queue is flushed. If the batch size is not reached, commands remain not executed.

Batching command interfaces are thread-safe and can be shared amongst multiple threads.

Since:

5.0

Author:

Mark Paluch

See Also:

CommandBatching, BatchExecutor

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
int	value	Declares the batch size for the command method.

Element Detail

value

int value

Declares the batch size for the command method.

Returns:

a positive, non-zero number of commands.