input: [Category] Instance Management [Description] For durable services that use the DurableService attribute to have WCF serialize and desterilize their state between calls, you need to configure the host with the details of a persistence provider in the config file. You need to derive from PersistenceProviderFactory and override a simple set of methods. The demo contains IDesign's FilePersistenceProviderFactory and FilePersistenceProvider, which as their name imply, persist the state of the service into a file. you will also see how to provide custom parameters in the config file (such as a file name) in the constructor of the persistence provider factory. The client still needs to manage the instance ID on its side, and that is done using the dedicated IDesign helper classed for context [Last Updated] 10/30/2008 [Title] 
output: Durable service using custom persistence provider