Workflow instances are not persisted when they should be

As demonstrated in the code at https://github.com/craigfowler/elsa-core/commit/672e32a7caae61355e928bc4c299e3687f468d17 (the new test added in this commit), the workflow instance which is created in this test never makes it to the MongoDb persistence store. This is despite the workflow including a UserTask activity which would suspend the workflow and preventing it from completing immediately.

This issue is to diagnose and fix this issue with workflow persistence. It has been proven to affect MongoDb and also anecdotally affects Entity Framework. Update: This is confirmed to affect all persistence, not just MongoDb.

Acceptance criteria

• A workflow should be persisted at at least one point after it has begun executing
• Test coverage must be added to prove that this works with at least an in-memory persistence store (ideally add a MongoDb test case as well)
• The default persistence behaviour for a workflow should be altered to be WorkflowPersistenceBehavior.WorkflowBurst (currently it is implicitly Suspended)

[craigfowler]

FYI I’ve repro’d this with in-memory persistence as well, so it seems like it affects all persistence providers (as @rzvdaniel suggested might be the case).

[rzvdaniel]

Very interesting explanation, @craigfowler.

Some of the above can easily go into documentation, like a QA section where you answer the question “Why my workflow instances aren’t persisted”? Same for the explanation of WorkflowPersistenceBehaviors, it can be a section in the Workflow Persistence chapter.

This ticket is revealing more details that you may have been thinking in the beginning.