Module lettuce.core
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 Details

    • value

      int value
      Declares the batch size for the command method.
      Returns:
      a positive, non-zero number of commands.