Cloudbees max number of websocket connections

Question

Does CloudBees impose any restriction on max number of concurrent websocket connections to a single ClickStack application? For instance some artificial of practical limitation in the front end machines dealing with incoming connections to CloudBees?

I realizes that it (the max number of concurrent websocket connections) to a large extent can depend on the specific ClickStack you use and the application infrastructure capacity you pay for at CloudBees, but I do not think that will be a problem in my case. In my case, I'll use the Play2 framework with many (hundreds up to a few thousand) low data/message rate websocket connections. Think of M2M sensor networks.

My guess is that it in the worst case builds up to a kind of slow loris starvation-thing, if there is a limit on maximum number of connections somewhere in the infrastructure and that is the reason why I'm asking.

Answer 1

There is no explicit limit placed on websocket connections.

Note that nginx and its websocket support is used by cloudbees. Nginx' async design is such that the bottleneck is generally IO - so it is rare that this layer (nginx) is the bottleneck. It is far more likely to be the application. Nginx can cope with many many connections - but each one has to end up being services by your application - so that typically is the bottleneck.

Thread starving can happen, and it really depends on the application and its framework used - different frameworks can have different failure modes.

The bigger issue is what framework you are using in your application - and then how many instances of that you want to run (and pay for).