Package com.tangosol.net

Interface Guardable

All Known Implementing Classes:
AsyncBinaryStore.QueueDaemon, Daemon, LoadBalancer.RequestHandler, LoadBalancer.ResponseHandler, LoadBalancer.SocketHandler, ReadWriteBackingMap.ReadThread, ReadWriteBackingMap.WriteThread, RefreshableAddressProvider.RefreshThread, TaskDaemon
public interface Guardable
A Guardable is a logical execution unit whose lifetime may be guarded by a Guardian. A Guardable may be a simple thread, or a more complex service.

Guardable objects are responsible for periodically proving that they are alive. Failure to do so will cause the Guardian to take corrective actions:

  1. The Guardian may attempt to revive the Guardable by calling recover.
  2. Upon failure to recover, the Guardian will abandon the Guardable by unregistering it and calling terminate.
Note: To prevent cascading failure (e.g. deadlock) all corrective actions are performed by the Guardian on temporary threads.

Guardable objects should be registered with an sufficiently sized SLA to accommodate variances in system-load, GC latencies etc. Guardians are not responsible for detecting or correcting for these conditions.

Since:
Coherence 3.5
Author:
rhl

  • Method Summary

    Modifier and Type
    Method
    Description
    Guardian.GuardContext
    getContext()
    Return the guard context monitoring this guardable, or null if this Guardable is no longer being monitored.
    void
    recover()
    Attempt to recover this Guardable.
    void
    setContext(Guardian.GuardContext context)
    Set the guard context.
    void
    terminate()
    Terminate this Guardable.

  • Method Details

    • setContext

      void setContext(Guardian.GuardContext context)
      Set the guard context. Passing in null indicates that the Guardable is no longer being monitored by a Guardian.
      Parameters:
      context - the context guarding this Guardable

    • getContext

      Guardian.GuardContext getContext()
      Return the guard context monitoring this guardable, or null if this Guardable is no longer being monitored.
      Returns:
      the context guarding this Guardable

    • recover

      void recover()
      Attempt to recover this Guardable.

      In a common case where the Guardable has an associated thread, a suitable action would be to interrupt the thread.

      If this method does not return before the timeout expires, the Guardable will be considered unrecoverable and will be terminated.

    • terminate

      void terminate()
      Terminate this Guardable.

      This is the final action taken by the Guardian before the Guardable is removed from its responsibility list.