title: Test multiple instances of a Web App in Azure App Service
body: <p>I have a web application that was being developed using Web Roles in Azure. It is a relatively complex application in which clients communicate with each other via the web server.  Client to server communication is via SignalR and within server instances Web Api is used.</p>
  
  <p>It was critical that it was tested against multiple instances of web roles since the all of plumbing needed to potentially communicate across the various instances of web roles.</p>
  
  <p>This was easy to do in web roles since in Visual Studio's project properties you would simply up the instance count and the Azure Compute Emulator would open a bunch of instances for you.</p>
  
  <p>After attending a recent Microsoft technical briefing, it was suggested that web roles were being superseded by Web Apps in Azure App Service.  Indeed on the surface these appeared to be a better fit to my problem and I have been investigating this as an architecture.</p>
  
  <p>The problem I have found is how to simulate multiple instances? Web Apps in development spin up in a single IIS express instance and thus have the same IP address on my development computer.  Web Roles spin up in difference instances and all have different IP addresses which makes testing easy.  From what I understand on production, web apps, if configured to have multiple instances, will get different IP addresses (and/or ports) since they may be running on different servers</p>
  
  <p>So how do I test multiple instances of Web Apps in the Azure App Service that need to cross communicate in development?</p>
  
  <p>...or am I just missing something big here?</p>
  
  <p>Thanks in advance.</p>
  
  <p>Dave A</p>