Solr on Docker: The Good, the Bad and the Ugly
This talk was given during Lucene Revolution 2017 and has two goals: first, to discuss the tradeoffs for running Solr on Docker. For example, you get dynamic allocation of operating system caches, but you also get some CPU overhead. We'll keep in mind that Solr nodes tend to be different than your average container: Solr is usually long running, takes quite some RSS and a lot of virtual memory. This will imply, for example, that it makes more sense to use Docker on big physical boxes than on configurable-size VMs (like Amazon EC2).
The second goal is to discuss issues with deploying Solr on Docker and how to work around them. For example, many older (and some of the newer) combinations of Docker, Linux Kernel and JVM have memory leaks. We'll go over Docker operations best practices, such as using container limits to cap memory usage and prevent the host OOM killer from terminating a memory-consuming process - usually a Solr node. Or running Docker in Swarm mode over multiple smaller boxes to limit the spread of a single issue.