Limit Java memory leaks from crashing the host

[aksm]

What?

When Cantaloupe is hit too hard (bots) Java can eat into kernel memory and crash the host. One potential option as suggested by @DiegoPino is to use the docker runtime option of --kernel-memory:

https://docs.docker.com/config/containers/resource_constraints/#--kernel-memory-details

Will test and report back.

[DiegoPino]

@aksm please look also at docker-compose / per service limits

[DiegoPino]

hitting cantaloupe via apache benchmark and disabling temporarily the cache might help hit the limits. doing a docker stats might help seeing if the limits are respected

[aksm]

After some load testing against Cantaloupe on a large image, the host server showed an almost 5% memory usage above that which was set in docker-compose for the container. I would guess that number will vary based on hardware/architecture/OS and amount of load over time so we'll need to account for the overhead. Maybe that's as simple as adjusting the upper limit on the service and adding a warning about the delta in documentation? @DiegoPino thoughts?

[DiegoPino]

a 5% sounds ok as part of the docs. basically document how to limit/a the docker-compose level (not all services I guess or all but with examples that work?) and assume that overhead. System is also using memory so we need to add an extra 10 to 20%?

Also: AWS EC2 machines don't provide 16Gbytes (even for a 16Gbyte system) but 15.2 Mbytes

Last thought. Filesystem memory/cache , basically swap?