Package com.tangosol.net

Interface Guardable

All Known Implementing Classes:

AbstractJournalRM.CollectorDaemon, AsyncBinaryStore.QueueDaemon, Daemon, FlashJournalRM.PreparerDaemon, FlashJournalRM.WriterDaemon, LoadBalancer.RequestHandler, LoadBalancer.ResponseHandler, LoadBalancer.SocketHandler, ReadWriteBackingMap.ReadThread, ReadWriteBackingMap.WriteThread, RefreshableAddressProvider.RefreshThread, SessionHelper.SessionReaperDaemon, 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 Detail

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.