catch

Applies a list of child processors only when a previous processing step has failed.

# Config fields, showing default values
label: ""
catch: []

Behaves similarly to the for_each processor, where a list of child processors are applied to individual messages of a batch. However, processors are only applied to messages that failed a processing step prior to the catch.

For example, with the following config:

pipeline:
  processors:
    - resource: foo
    - catch:
      - resource: bar
      - resource: baz

If the processor foo fails for a particular message, that message will be fed into the processors bar and baz. Messages that do not fail for the processor foo will skip these processors.

When messages leave the catch block their fail flags are cleared. This processor is useful for when it’s possible to recover failed messages, or when special actions (such as logging/metrics) are required before dropping them.

More information about error handling can be found in xref:configuration:error_handling.adoc[].