Yes, it will do GC automatically, but only after some threshold has been reached. It doesn't collect as soon as something is no longer referenced.
So you typically see a sawtooth pattern where memory increases for a while, then drops back when a GC happens, then increases, then drops back. Problem is that you never quite know when the GC has kicked in and whether it's collected everything from all the spaces or not. Usually tools like jConsole collect everything that can be collected.... I'm not recommending you manually force GCs as a regular thing, just to answer whether memory is really creeping up when you're not doing anything by being able to set your expectations. NOTE: I expect the permanently-used memory to increase from a fresh start for a while, but level out pretty soon. Best, Erick On Thu, Apr 14, 2016 at 12:00 PM, Betsey Benagh <betsey.ben...@stresearch.com> wrote: > Thanks for the quick response. Forgive the naïve question, but shouldn¹t > it be doing garbage collection automatically? Having to manually force GC > via jconsole isn¹t a sustainable solution. > > Thanks again, > betsey > > On 4/14/16, 2:54 PM, "Erick Erickson" <erickerick...@gmail.com> wrote: > >>well, things _are_ running, specifically the communications channels >>are looking for incoming messages and the like, generating garbage >>etc. >> >>Try attaching jconsole to the process and hitting the GC button to >>force a garbage collection. As long as your memory gets to some level >>and drops back to that level after forcing GCs, you'll be fine. >> >>Best, >>Erick >> >>On Thu, Apr 14, 2016 at 11:45 AM, Betsey Benagh >><betsey.ben...@stresearch.com> wrote: >>> X-posted from stack overflow... >>> >>> I'm running solr 6.0.0 in server mode. I have one core. I loaded about >>>2000 documents in, and it was using about 54 MB of memory. No problem. >>>Nobody was issuing queries or doing anything else, but over the course >>>of about 4 hours, the memory usage had tripled to 152 MB. I shut solr >>>down and restarted it, and saw the memory usage back at 54 MB. Again, >>>with no queries or anything being executed against the core, the memory >>>usage is creeping up - after 17 minutes, it was up to 60 MB. I've looked >>>at the documentation for how to limit memory usage, but I want to >>>understand why it's creeping up when nothing is happening, lest it run >>>out of memory when I limit the usage. The machine is running CentOS 6.6, >>>if that matters, with Java 1.8.0_65. >>> >>> Thanks! >>> >
