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What is a Retry Policy?

A Retry Policy is collection of attributes that instructs the Temporal Server how to retry a failure of a Workflow Execution or an Activity Execution.

  • When a Workflow Execution is invoked it is not associated with a default Retry Policy and thus does not retry by default. The intention is that a Workflow Definition should be written to never fail due to intermittent issues; an Activity is designed to handle such issues.
note

Retry Policies do not apply to Workflow Task Executions, which, by default, retry indefinitely.

Default values for Retry Policy

Initial Interval     = 1 secondBackoff Coefficient  = 2.0Maximum Interval     = 100 × Initial IntervalMaximum Attempts     = ∞Non-Retryable Errors = []

Initial Interval#

  • Description: Amount of time that must elapse before the first retry occurs.
    • The default value is 1 second.
  • Use case: This is used as the base interval time for the Backoff Coefficient to multiply against.

Backoff Coefficient#

  • Description: The value dictates how much the retry interval increases.
    • The default value is 2.0.
    • A backoff coefficient of 1.0 means that the retry interval always equals the Initial Interval.
  • Use case: Use this attribute to increase the interval between retries. By having a backoff coefficient greater than 1.0, the first few retries happen relatively quickly to overcome intermittent failures, but subsequent retries happen farther and farther apart to account for longer outages. Use the Maximum Interval attribute to prevent the coefficient from increasing the retry interval too much.

Maximum Interval#

  • Description: Specifies the maximum interval between retries.
  • Use case: This attribute is useful for Backoff Coefficients that are greater than 1.0 because it prevents the retry interval from growing infinitely.

Maximum Attempts#

  • Description: Specifies the maximum number of execution attempts that can be made in the presence of failures.
    • The default is unlimited.
    • If this limit is exceeded, the execution fails without retrying again. When this happens an error is returned.
    • Setting the value to 0 also means unlimited.
    • Setting the value to 1 means a single execution attempt and no retries.
    • Setting the value to a negative integer results in an error when the execution is invoked.
  • Use case: Use this attribute to ensure that retries do not continue indefinitely. However, in the majority of cases, we recommend relying on the Workflow Execution Timeout, in the case of Workflows, or Schedule-To-Close Timeout, in the case of Activities, to limit the total duration of retries instead of using this attribute.

Non-Retryable Errors#

  • Description: Specifies errors that shouldn't be retried.
  • Use case: There may be errors that you know of that should not trigger a retry. In this case you can specify them such that if they occur, the given execution will not be retried.