在长时间运行的工作流服务上调用操作（接收活动）时，WF4错误

Question

The error: The execution of an InstancePersistenceCommand was interrupted because the instance '42ca66e7-35e3-462e-9594-a98ee009d2e2' has not yet been persisted to the instance store.

This happens when I call the 2nd receive activity on an existing workflow instance that has been unloaded from memory. If the instance is still in memory, I don't have the problem. The instance gets unloaded after waiting for 1 minute or stopping the debugger.

I can see a record in the System.Activities.DurableInstancing.InstancesTable table with the id 42CA66E7-35E3-462E-9594-A98EE009D2E2.

Any idea why I'm having this problem?

Update

It seems like my state of the workflow isn't being persisted and/or persistence isn't happening properly. Here's is a workflow instance record in the System.Activities.DurableInstancing.InstancesTable table. Is it just me or should I see some serialized state in there somewhere?

What would happen if I were using a class not marked as [Serializable] in my workflow and tried to persist it?

Answer 1

I found that serialization was being interrupted because of some problems with some types that were used in the workflow.

The first problem was that I had marked a property with [DataMember] that didn't have a set accessor. NetDataContractSerializer wasn't able to serialize that type until I removed the attribute.

The second problem was that I had a workflow variable of type IEnumerable, which obviously isn't marked as Serializable or DataContract. I'm not sure what I was thinking when I did that.

These problems were easy to spot after learning about the WorkflowServiceTraceBehavior on Ron Jacobs blog .