检查WCF通信通道状态的正确方法

Question

I am developing a WCF client / server solution which I need to have the communication channel available 24/7 as there is a windows service that publishes data continually - my WF implementation is a Subscribe/Publish service. I have put some things together but seem to have issues losing connections and some other nefarious problems. As I was reading on Microsoft website about checking the Communication Object Checking the value of the ICommunicationObject.State property is a race condition and is not recommended to determine whether to reuse or close a channel. However the examples I have been seeing all use this technique! Microsoft makes that notation but gives no further information or advice in regards to how to do it "PROPERLY".

So I would like to know what is the proper way to do this - those with experience regarding this please chime in and help I as I am learning WCF - I can use good tips of how to's.

Answer 1

So I would like to know what is the proper way to do this

Well, a race condition is a race condition - they are impossible to catch before the fact because they have not hapenned yet. So your expectation of being able to know the state of the channel before you call it is unreasonable.

However, we know we should always be able to reuse a channel if it is not in a faulted (or closed) state. So we can just wrap our call to the channel in a try...catch and then handle exceptions as appropriate .

If the channel is not reusable then this is actually an error condition which needs to be handled after the fact. In a workflow, you could usually implement this as a compensation mechanism, perhaps by creating another channel and then calling it.