Use the Workflow Validation tool in vCO!

One of the first things I got teached during my studies was: Always deliver code that compiles with

0 Warnings, 0 Errors“!

We had to follow that principle while trying to let LEDs blink (I miss a vCO-Plugin for MPC555 :-D) , but I still remember my Prof.’s words when I develop workflows.

The vCenter Orchestrator provides a Workflow validation mechanism, which checks the workflow for

  • open ends
  • unreachable workflow elements
  • unused workflow Attributes
  • unbound IN- and OUT parameters of workflow elements
  • formal errors in scriptable tasks (JavaScript)
  • unbound Exceptions (if you use an Exception connector)
  • Unset parameters in Configuration Elements

You can run the validation by pressing the “Validate”-Button in the Workflow editor, or in the context menu of a workflow in the workflowlList.

The results of the validation is shown in a popup window. There are two kinds of validation issues:
Errors are hard formal violations which prevent the workflow from running sucessful.
Warnings are “soft” violations: Your workflow can be started, but it likely has some bugs.

For some of the validation results “Quick Fix actions” are recommended. They might fix the issue, but do not trust them blindly!

When you ran the validation at least once, errors and warnings are also shown as small red or yellow symbols directly at the related workflow element in the schema. This is very helpful for larger workflows!

By default a workflow is also validated before you start it (only when you try to start the workflow in the vCO Client, not via weboperator nor the SOAP API!). If your workflow has an error (warnings don’t matter), you cannot start the workflow, and you’ll get this error message:

You can change this behavior in the menue “Tools / User Preferences… ” of the vCO client, there in the “Workflows”-section (the checkbox is labeled with “Validate workflow before running it”). I recommend to only do this in your development environment, when you want to start workflows with errors (e.g. while they’re not developed completely yet)!

Also be aware:
The Workflow Validation only can check for formal errors. Semantic errors in your workflow and its JavaScript parts can not be detected by the validation.
A valid workflow is not necessarily error-free!

In very rare caes you also might get some false positives in the validation results. The only situation I remember is, when you need a workflow attribute only for input presentation processing, but not in the workflow: You’ll get a “Attribute XYZ is never used!” warning (, and the quick-fix would delete it and break the processing of input presentation!).

In sum: Always end up with a workflow that shows “0 Warnings, 0 Errors“! :mrgreen: