Error Handling in batch Commands

Introduction

When executing batch commands in Coordinator, understanding error handling is crucial for building robust and resilient sequences. By default, if any step in a batch encounters an error, the entire batch execution will stop. However, batch provides a mechanism to allow certain steps to continue execution even if they encounter errors. This is achieved through the use of the allowFailure keyword.

Basic Error Handling

In a typical batch command execution, if any step encounters an error, the entire batch execution is halted. This ensures that issues are addressed before moving on to subsequent steps. Consider the following example:

version: 1
steps:
  - description: Step 1 - Successful Operation
    action: test.run
    args:
      target: qa
      script: test_script_1.js
  - description: Step 2 - Failing Operation
    action: test.run
    args:
      target: qa
      script: test_script_2.js # This script contains an intentional error

In this example, if "Step 1" is successful but "Step 2" encounters an error, the entire batch execution will be stopped.

Introducing allowFailure Keyword

To allow specific steps to continue execution even if they encounter errors, you can use the allowFailure keyword. This keyword is applied at the step level in the recipe, indicating that the batch should proceed to the next step regardless of the success or failure of the current step.

Consider the following modified example:

version: 1
steps:
  - description: Step 1 - Successful Operation
    action: test.run
    args:
      target: qa
      script: test_script_1.js
  - description: Step 2 - Ignoring Failure
    action: test.run
    args:
      target: qa
      script: test_script_2.js # This script contains an intentional error
    allowFailure: true
  - description: Step 3 - Subsequent Operation
    action: test.run
    args:
      target: qa
      script: test_script_3.js

In this example, even if "Step 2" encounters an error, the allowFailure keyword allows the batch to continue to "Step 3."