WCF Error - The operation has timed out

We have created a WCF service hosted in a windows service that handles Authentication requests.

The only behavior is :

ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
smb.HttpGetEnabled = true;
selfHost.Description.Behaviors.Add(smb);

Our clients are able to authenticate succesfully 10 times then we get the error

The operation has timed out

When we increase the MaxConcurrentSessions = 50 then our clients can authenticate 50 times before we see the error. Clearly sessions are not being cl开发者_StackOverflow中文版osed after the authentication call is made can anyone tell why this might be happening?

When you say "clients", do you mean multiple independent clients, or the same client (i.e. single process) doing 50 requests? What's your instancing mode for the service, and what binding are you using?

At first glance, I'd say your clients are leaking sessions by not disposing client-side proxies correctly and the instancing mode is getting in the way.