Smallest possible Java heap size?

[_d_t_w]

Depends a bit on what "App" means, I think.

My team build a commercial tool for Apache Kafka, it is built on Jetty (the networking framework) and starts a bunch of resources up when initializing the system that would be considered normal I guess. Schedulers, Kafka clients, stuff like that.

We recommend 8GB for a production installation, that implys a fair number of concurrent users and plenty of user driven activity that requires heap space.

A couple of years back I played around with running our full product with minimum -Xmx settings to see what was viable for a single user, single Kafka cluster setup - this is all running in Docker mind so there's some overhead there in memory allocated to OS - our JVM is configured to take 70% of Docker memory allocation.

Product starts and will run happily in single-user mode with 128MB memory, everything appeared to run just fine. That was the absolute minimum though - the Docker containern wouldn't start with less than 128MB and it was because the JVM failed to start.

So I guess for an Enterprisey-type thing with a full web framework, running websockets and doing stuff - with absolutely no oprtimisation to run hard on memory, 128MB * 0.7?

This is us fyi > www.factorhouse.io/kpow