What are the recommended values and meaning of the WCF Throttling counters?

Question

I have a WCF running service with throttling values as

The way I understood the counters is that Concurrent calls govern the number of requests currently being executed, Concurrent sessions govern the number of requests in wait queue and concurrent instances is the sum of both.

We have a scenario, where the Percent of concurrent calls are going > 100 but the percent of concurrent session is always 0.

I am deeply confused about the meaning of these counters and the values I am getting.

Any Help, is appreciated

Answer 1

Three points to check in order to have a session

1 Use a session enabled binding

For instance, check that you aren't using basicHttpBinding for instance. That binding doesn't support sessions.

Prefer wsHttpBinding or netTcpBinding or namedPipeBinding

2 Enable session on the service implementation

[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class BillingService { ... }

3 Allow or requires the session on the service interface

[ServiceContract(SessionMode=SessionMode.Allowed)]
public interface IBillingService { … }

You can check if there is a current session :

1 Server side

string sessionId = OperationContext.Current.SessionId;

2 Client side

string sessionId = proxy.InnerChannel.SessionId;

Regards