Will Beattie's Blog

  Recently I wrote about how some of the Serialization problems you can face when dealing with long running workflows. In this post I’m going to cover how I deal with logic changes in persisted workflows and also how you can make logic changes to your workflows without having to deploy code. Hosting the Workflow When it comes to hosting your workflows there are really only two options to consider. Self-Hosting WCF Workflow Service To be honest I only looked at the WCF Workflow Service model briefly and decided it wasn’t the best fit for the requirements as it couldn’t provide the same benefits of self-hosting within a Workflow Application . Workflow Instance Store In order to persist Workflow instances you need to first create the Workflow Instance Store database. For this you will need to use the following scripts: C:\Windows\Microsoft.NET\Framework\v4.0.30319\SQL\en\SqlWorkflowInstanceStoreSchema.sql C:\Windows\Microsoft.NET\Framework\v4.0.30319\SQL\en\Sq...

  I’ve been using Workflow Foundation now for over a year and it has become an integral part of our architecture and has by and large been very successful. However it is not without it’s issues, the single most being that official documentation is light at best and relevant blog posts are quite rare.   I recently ran into a fairly serious problem after deploying a new release of our Software. The Problem I received this lovely email from our exception tracker: System.Runtime.DurableInstancing.InstancePersistenceCommandException: The execution of the InstancePersistenceCommand named {urn:schemas-microsoft-com:System.Activities.Persistence/command}LoadWorkflow was interrupted by an error. ---> System.Runtime.Serialization.SerializationException: Deserialized object with reference id '73' not found in stream. The key part is “Deserialized object with reference id '73' not found in stream.” As I’m sure you can tell this does not really provide any helpful i...