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Timeout

Bound work with graceful timeout and dead-end paths.

Problem and approach​

Overview​

The FlowGracefulTimeout serves as an example of managing tasks using a timeout mechanism. This Flow ensures that tasks are completed within a designated time frame. If a task exceeds this duration, the Flow can forcibly terminate to prevent endless execution or a log can be emitted and the Step can return StepDecision.deadEnd().

Flow Details​

(diagram omitted — see example README)

(diagram link)

Flow Steps​

  • InitStep: Accepts a Boolean indicating whether the Flow should simulate a successful or long-running task that exceeds the timeout. Transitions to both TimeoutStep and TaskStep simultaneously, allowing them to run in parallel.
  • TimeoutStep: Waits for a timer to complete, set to 1 minute. If the timer completes before the task, it forcefully fails the Flow, indicating that the task did not finish in time.
  • TaskStep: Represents the main task execution within the Flow. Accepts a Boolean to determine if the task should complete successfully or exceed the timeout. If simulating a delay, waits for a timer longer than the timeout (65 seconds) fails the Flow. If the task completes successfully, it forcefully completes the Flow, closing the timeout Step thread.

Usage​

  1. Start a Flow using an endpoint. Example:
http://localhost:8080/design-pattern/timeout/start?FlowId=handleTimeoutFlow
  1. If you want the timeout Step to be triggered add the parameter successfulFlow=false
http://localhost:8080/design-pattern/timeout/start?FlowId=handleTimeoutFlow&successfulFlow=false

Code examples​

Full runnable samples live under examples/{go,java,python,typescript} (HTTP prefix /design-pattern/... where applicable).

# See examples/python/dex_examples/patterns/workflow/timeout/