Automatic Error Handling

Overview

If a process encounters a problem within a given activity, the process flow halts at the activity. One of two things occur.

  1. If it encounters a safeToRetry exception, it is automatically retried.
    • If the error was transient, the activity completes and process flow resumes.
    • If the error is not resolved after the maximum number of retries, the activity becomes canceled by exception.
  2. If it encounters an Activity Execution Exception it becomes canceled by exception.

See also: Process Errors

Automatic Retries

A number of internal and external operations provide error-handling retries to respond automatically should your application or network experience minor disruptions due to time-out errors, such as a very heavy transaction load.

The transaction is only retried when no data has been updated or changed.

Internal Error Handling

See also: Process Nodes and Smart Services and Appian Functions

External Error Handling

Retry Intervals

Should an error occur, automatic retries occur at approximately the following intervals after each subsequent error. The interval between retries roughly doubles after each attempt.

  • 32 seconds
  • 64 seconds
  • 127 seconds
  • 4.5 minutes
  • 9 minutes
  • 17 minutes
  • 34 minutes
  • 67 minutes
  • 135 minutes
  • 4 hours and 30 minutes
  • 9 hours
  • 18 hours

If the retry that occurs after the last interval fails, no additional retries occur.

It is not possible to predict exactly when a subsequent retry occurs, due to the variable time spent retrying and catching each new error.

Logging

Retries are logged at the Debug level in the engine server logs.

Final retries are logged as errors.

See also: Application Engine and Gateway Logging

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