title: SignalR Scale out using a backplane
body: <p>I am confused on a design architecture using a SQL server as a back-plane. My question is can I use Redis as a back-plane and also have SQL serving my user information separate from SignalR messages. </p>
  
  <p>I am just very lost on where my SQL server database would fit into this diagram. Is it as simple as just adding my connection string in the web config and when the user needs to hit the db it does, but is always connected to Redis for SignalR? Or is that design architecture not possible because the backplane is the end point of all data being sent?</p>
  
  <p>One last thing I would like to ask is if I end up just using SQL as my scale out design with signalr. If at some point the back-plane becomes a bottleneck, how does that scale? Is my only option to scale vertically or horizontally?</p>
  
  <p><img src="https://i.stack.imgur.com/01Pip.jpg" alt="Scale-out provider architecture"></p>
  
  <p>Please look at this new image of the diagram,</p>
  
  <p><img src="https://i.stack.imgur.com/98fC3.jpg" alt="Scale-out provider architecture with SQL DB"></p>