errorStrategy

The errorStrategy directive defines how to handle task failures.

A task failure occurs when the executed script returns a non-zero exit code. By default, the pipeline run is aborted.

The following error strategies are available:

'terminate' (default)

When a task fails, terminate the pipeline immediately and report an error. Pending and running jobs are killed.

'finish'

When a task fails, wait for submitted and running tasks to finish and then terminate the pipeline, reporting an error.

'ignore'

When a task fails, ignore it and continue the pipeline execution. If the workflow.failOnIgnore config option is set to true, the pipeline will report an error (i.e. return a non-zero exit code) upon completion. Otherwise, the pipeline will complete successfully.

See the workflow namespace for more information.

'retry'

When a task fails, retry it.

When setting the errorStrategy directive to ignore the process doesn't stop on an error condition, it just reports a message notifying you of the error event.

For example:

process hello {
    errorStrategy 'ignore'

    // ...
}

In this case, the workflow will complete successfully and return an exit status of 0. However, if you set workflow.failOnIgnore = true in your Nextflow configuration, the workflow will return a non-zero exit status and report the failed tasks as an error.

The retry error strategy retries failed tasks. For example:

process hello {
    errorStrategy 'retry'

    // ...
}

The number of times a failing process is re-executed is defined by the maxRetries and maxErrors directives.

tip

More complex strategies depending on the task exit status or other parametric values can be defined using a dynamic errorStrategy. See Dynamic directives for details.

See also: maxErrors, maxRetries, dynamic task resources