Rollback error handler
The Rollback error handler stops the Action Flow run and reverts changes made by modules that support transactions. They always use a database app, like MySQL or Data store. Celonis platform cannot undo actions made by modules that don't support transactions, like Gmail > Send an email or Dropbox > Delete a file.
For example: This demo Action Flow contains five modules. The Action Flow is useful for tests and showing the effect of an error handler:
JSON - Parse JSON provides test data in the form of an array of three record IDs.
Iterator splits the array into individual bundles.
Data store - Update a record: Updates the data in the data store.
Data store - Update a record: This module updates the data again. This time the module works differently. In the module mapping, there is a mapping that intentionally creates an error:
The mapping inserts a
nullvalue into the required Key field, which always creates theBundleValidationError.Having two data store modules doing the same thing, but one of them failing, will make a good example for the Commit and Rollback error handlers.
Slack - Send a message: Sends a message to a private testing channel.
This is how the example Action Flow looks:
When we would run the example Action Flow, we would get the BundleValidationError:
With the Rollback error handler, you can stop the Action Flow and undo changes when the module outputs an error. You can only undo changes in modules that support transactions.
For example, the following Action Flow outputs an error in the Data Store app module:
To stop the Action Flow and undo changes where possible when an error happens, follow the steps:
Right-click the module that is causing the error. In the menu, select Add error handler.
Select the Rollback error handler.
Optional: Go to Action Flow settings and disable the Auto-commit option.
When an error happens, the module that outputs the error reverts changes if the module supports transactions. If you disable the Auto-commit option, all modules in the Action Flow that support transactions undo changes.
Save your Action Flow.
You added the Rollback error handler to your Action Flow. When an error occurs in the Data store module, the Action Flow stops and Celonis platform reverts changes made by the erroring bundle in modules that support transactions.
