IBM Case Manager: Intermittantly getting "Update sequence number mismatch" trying to save case

Question

I'm using the Java API with Case Manager 5.2.1, on Windows.

My web service does the following:

// Create a brand new case
CaseType myCaseType = CaseType.fetchInstance(osRef, myCaseTypeName);
Case newPendingCase = Case.createPendingInstance(myCaseType);

// Save it now to get access to the Case ID
newPendingCase.save(RefreshMode.REFRESH, null, ModificationIntent.MODIFY);
newCaseIdentifier = newPendingCase.getIdentifier();

// Fetch a fresh copy of the case instance
Case cs = Case.fetchInstanceFromIdentifier(osRef, newCaseIdentifier);

// Now set a whole bunch of properties, add documents, etc. etc.
...

// Finally, save all our updates: to "cs", not "newCaseIdentifier"
cs.save(RefreshMode.REFRESH, null, ModificationIntent.MODIFY);

PROBLEM: I intermittently get this error:

The object {52EECAC2-38B2-4CB5-8F22-BAF33D6C35EC} of class "MyCaseTypeName" was not changed or deleted because it was modified one or more times in the repository since the application retrieved it. Update sequence number mismatch; requested USN = 0, database USN = 1

I know there are only two case.save() calls: one for "newPendingDocument", the other (much later) for "cs".

I execute the SAME code multiple times: sometimes it works, sometimes if fails with the "Update sequence number mismatch" error.

Q: Any ideas/any suggestions as to how I can troubleshoot this problem?

Answer 1

Looking at the code that you provide I am confused as to why you would create a second Case instance. I would imagine that you would be better off doing this instead:

// Create a brand new case
CaseType myCaseType = CaseType.fetchInstance(osRef, myCaseTypeName);
Case newPendingCase = Case.createPendingInstance(myCaseType);

// Save it now to get access to the Case ID
newPendingCase.save(RefreshMode.REFRESH, null, ModificationIntent.MODIFY);
newCaseIdentifier = newPendingCase.getIdentifier();

// Fetch a fresh copy of the case instance (not sure if this is necessary)
newPendingCase = Case.fetchInstanceFromIdentifier(osRef, newCaseIdentifier);

// Now set a whole bunch of properties, add documents, etc. etc.
...

// Finally, save all our updates: to "newPendingCase"
newPendingCase.save(RefreshMode.REFRESH, null, ModificationIntent.MODIFY);

I haven't worked with Case Manager, but have worked with P8. The api calls are very similar.

The USN number can be a little tricky. If there is any time period that you are waiting for an external call (to a 3rd party REST interface for instance) you might want to do a newPendingCase.Refresh() after the call, and then repopulate any needed properties of the case.