Package io.micronaut.context.annotation

Annotation Interface Parallel

@Documented @Retention(RUNTIME) @Target({METHOD,TYPE,ANNOTATION_TYPE}) public @interface Parallel

A hint annotation that can be added to Bean definitions or Executable methods to indicate that they can be initialized in parallel with the application context.

This allows optimized startup time by allowing beans that have slow initialization paths to startup and without impacting the overall startup time of the application.

Note that beans and methods that are processed in parallel (unlike Context scoped beans) will not initially fail the startup of the ApplicationContext as they may be initialized after the ApplicationContext has started and cannot participate in StartupEvent processing. If a parallel bean fails to startup it will by default stop the ApplicationContext with an error unless shutdownOnError() set to to false.

Adding Parallel to methods is most useful when used in conjunction with a ExecutableMethodProcessor. Be aware however, that the processor in this case should be thread safe as could be executed in parallel for different methods.

NOTE: The use of Parallel generally only makes sense when combined with non Prototype scopes such as Singleton and Context

Since:
1.0
Author:
graemerocher
See Also:

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    boolean
    shutdownOnError
    The default behaviour is to shutdown the context if an error occurs on initialization.

  • Element Details

    • shutdownOnError

      boolean shutdownOnError
      The default behaviour is to shutdown the context if an error occurs on initialization. Can be set false if shutdown is not required.
      Returns:
      Whether to shutdown the application if an error occurs.
      Default:
      true