Increase the wcf web service performance with separating one project to two projects

问题

I’m new in .net and it’s really hard to me explain my problem. So if you think I didn’t provide enough information or anything else, feel free and tell me.

I have a web service for sending the text message. I receive an array of messages in input then send them. In the background, I have the queue. I put each message in the queue then send it. I treat them like a task. Each task has a maximum try count, timeout and ... Sometimes I have to try many times in order to send a single message. This Couse great overhead in my server. (In average I try about 10 million times in a day and I only send about 6 million messages successfully.)

But sometimes my web service users receive the timeout. I increase the IIS queue length to maximum and set the maximum worker process to 0. But the problem didn’t solve. Finally, I separate the project in two. One as an interface. Users call this interface and I put them in the queue. And another one just for the tasks. It does the queue tasks. Then problem solved. 1- I didn’t change the server resources. 2- I didn’t change the code logic(I just convert it to two projects) Then my web service stops returning timeout error.

Here is my question: can I do it without separating the projects? Do I miss something in IIS configure?

UPDATE:

1. my web service application hosted in IIS 8 and I use the WCF technology.
2. I increase the max connections to 1000, maxConcurrentCalls, maxConcurrentSessions, maxConcurrentInstances, and max iis workers to thing got little better but in compare to separate projects it's not good at all.
3. I close the client in all my projects.

4. here is part of my web config:

     <serviceBehaviors>
       <behavior name="ServiceBehavior">
         <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true" />
         <serviceDebug includeExceptionDetailInFaults="true" />
         <serviceThrottling maxConcurrentCalls="2147483647" maxConcurrentSessions="2147483647" maxConcurrentInstances="2147483647" />
       </behavior>
     </serviceBehaviors>
   </behaviors>
   
   <connectionManagement>
     <add address="*" maxconnection="1000" />
   </connectionManagement>
   

来源：https://stackoverflow.com/questions/38279272/increase-the-wcf-web-service-performance-with-separating-one-project-to-two-proj