org.apache.flink.streaming.runtime.tasks

Interface TimerService

All Superinterfaces:

ProcessingTimeService

All Known Implementing Classes:

SystemProcessingTimeService, TestProcessingTimeService

@Internal
public interface TimerService
extends ProcessingTimeService

A common timer service interface with life cycle methods.

The registration of timers follows a life cycle of three phases:

1. In the initial state, it accepts timer registrations and triggers when the time is reached.
2. After calling ProcessingTimeService.quiesce(), further calls to ProcessingTimeService.registerTimer(long, ProcessingTimeCallback) will not register any further timers, and will return a "dummy" future as a result. This is used for clean shutdown, where currently firing timers are waited for and no future timers can be scheduled, without causing hard exceptions.
3. After a call to shutdownService(), all calls to ProcessingTimeService.registerTimer(long, ProcessingTimeCallback) will result in a hard exception.

Method Summary

Modifier and Type	Method and Description
boolean	isTerminated() Returns true if the service has been shut down, false otherwise.
void	shutdownService() Shuts down and clean up the timer service provider hard and immediately.
boolean	shutdownServiceUninterruptible(long timeoutMs) Shuts down and clean up the timer service provider hard and immediately.

Methods inherited from interface org.apache.flink.streaming.runtime.tasks.ProcessingTimeService

getCurrentProcessingTime, quiesce, registerTimer, scheduleAtFixedRate, scheduleWithFixedDelay

Method Detail

isTerminated

boolean isTerminated()

Returns true if the service has been shut down, false otherwise.

shutdownService

void shutdownService()

Shuts down and clean up the timer service provider hard and immediately. This does not wait for any timer to complete. Any further call to ProcessingTimeService.registerTimer(long, ProcessingTimeCallback) will result in a hard exception.

shutdownServiceUninterruptible

boolean shutdownServiceUninterruptible(long timeoutMs)

Shuts down and clean up the timer service provider hard and immediately. This does not wait for any timer to complete. Any further call to ProcessingTimeService.registerTimer(long, ProcessingTimeCallback) will result in a hard exception. This call cannot be interrupted and will block until the shutdown is completed or the timeout is exceeded.

Parameters:

timeoutMs - timeout for blocking on the service shutdown in milliseconds.

Returns:

returns true iff the shutdown was completed.