Different SessionID in multiple Proxy Client?

Question

User328625153 posted

Hi Hi,

My WCF service is implemented using [InstanceContextMode = InstanceContextMode.Single] with an operation to return the [OperationContext.Current.SessionId] back to the client.

In my client, I have created 2 proxies as shown below:

private void button1_Click(object sender, EventArgs e)
        {
            if (proxy1 == null)
            {
                proxy1 = new SpaceShipSvc.SpaceShipSvcClient("UseWSBinding");
                proxy1.Open();
            }

            
            string tmp = proxy1.GetInstanceSessionInfo(); //this will return the OperationContext.Current.SessionId
            string sessionid = proxy1.InnerChannel.SessionId;
            
            listBox1.Items.Add(string.Format("Proxy1 <{0}>: {1}", sessionid, tmp));
        }


        private void button2_Click(object sender, EventArgs e)
        {
            if (proxy2 == null)
            {
                proxy2 = new SpaceShipSvc.SpaceShipSvcClient("UseWSBinding");
                proxy2.Open();                
            }

            
            string tmp = proxy2.GetInstanceSessionInfo();
            string sessionid = proxy2.InnerChannel.SessionId;
            listBox1.Items.Add(string.Format("Proxy2 <{0}>: {1}", sessionid,tmp));
        }

The result is that proxy1 and proxy2 yield 2 different SessionID.

My question is, if my service's instancecontextmode is single, shouldn't I be getting only one SessionID?

Thanks Thanks.

Answer 1

User-760709272 posted

Single just means that only one call will executed at a time.

Answer 2

User328625153 posted

Pardon me ... I don't quite understand.

By defining my service as [InstanceContextMode.Single], only 1 service instance will be created at the host and be shared with the multiple clients/proxies. With the 1 service instance, the variable declared in my service will be shared with the multiple clients/proxies. E.g.

[ServiceBehavior(InstanceContextMode=InstanceContextMode.Single)] 
public class CalculatorService : ICalculatorInstance 
{ 
   int instanceCount=0;

   public int getInstanceCount(){
        return instanceCount++;
   }
   
}

Both my proxyClient1 and proxyClient2 will share the same [instanceCount] variable. Therefore, in regardless of which proxyClient calls the [getInstanceCount()], the value returned will be {0,1,2,3,4 ...}.

If that is the case, shouldn't both of my proxies contain the same sessionID?

Answer 3

User260886948 posted

Hi,

In the single mode, the SessionID will be different accroding to different Proxy client.
As you said that by defining your service as [InstanceContextMode.Single], only 1 service instance will be created at the host and be shared with the multiple clients/proxies. But the SessionID is different, if your proxy client is different.

Best Regards.