The short answer is – IceBreak scales extremely well, since it is the only web server / application server that was designed to run on system i in the ILE environment with the one goal to outperform the build in apache server.

The design of IceBreak may answer your question – and I'll give you some numbers later in this post.

The session management and the applications server is designed to be similar to the session you know from 5250. So a session in IceBreak is actually a tiny IBMi job as you know it from interactive jobs on the system i. The trick here is to let IBMi operating system do the scaling which it have been doing quite well now for at least two decades.

The web server in IceBreak is at least one job job that serves up to 256 clients at the time – one thread for each communication request (socket connection) from the client. Again – we let the IBMi operating system do the real work of load balancing by starting a new job for each 256 client – so e.g. 10 jobs will serve 2560 clients simultaneous.

Our test bench with 1000 simultaneous clients on a model 170 ( quite old model)  gives icebreak a 3 times better performance that a Apache –CGI application; when you run - and at least 20 times better performace to JAVA web-sphere.

The reason is that icebreak has an extreme little footprint on the system, so all the power is used to run the application and not used to run the environment.

So when you ask – does IceBreak scale. We can answer with a new question: Does IBMi scale?

Best regards,

Niels Liisberg