I'm not sure this issue applies in this situation but it's worth taking a look at:
https://issues.apache.org/jira/browse/SOLR-12833?focusedCommentId=16807868&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16807868 Although the memory issue in the ticket involves different versions than I think are being discussed. It's good to understand that this issue exists and that it's resolved going forward. Also because the way that this issue is attached to the original ticket that caused the bug, rather than a new bug report, it's very hard to know that this problem actually existed. Joel Bernstein http://joelsolr.blogspot.com/ On Sun, May 26, 2019 at 3:30 PM Shawn Heisey <apa...@elyograg.org> wrote: > On 5/26/2019 12:52 PM, Joe Doupnik wrote: > > I do queries while indexing, have done so for a long time, without > > difficulty nor memory usage spikes from dual use. The system has been > > designed to support that. > > Again, one may look at the numbers using "top" or similar. Try Solr > > v8.0 and 8.1 to see the difference which I experience here. For > > reference, the only memory adjustables set in my configuration is in the > > Solr startup script solr.in.sh saying add "-Xss1024k" in the SOLR_OPTS > > list and setting SOLR_HEAP="4024m". > > There is one significant difference between 8.0 and 8.1 in the realm of > memory management -- we have switched from the CMS garbage collector to > the G1 collector. So the way that Java manages the heap has changed. > This was done because the CMS collector is slated for removal from Java. > > https://issues.apache.org/jira/browse/SOLR-13394 > > Java is unlike other programs in one respect -- once it allocates heap > from the OS, it never gives it back. This behavior has given Java an > undeserved reputation as a memory hog ... but in fact Java's overall > memory usage can be very easily limited ... an option that many other > programs do NOT have. > > In your configuration, you set the max heap to a little less than 4GB. > You have to expect that it *WILL* use that memory. By using the > SOLR_HEAP variable, you have instructed Solr's startup script to use the > same setting for the minimum heap as well as the maximum heap. This is > the design intent. > > If you want to know how much heap is being used, you can't ask the > operating system, which means tools like top. You have to ask Java. > And you will have to look at a long-term graph, finding the low points. > An instananeous look at Java's heap usage could show you that the whole > heap is allocated ... but a significant part of that allocation could be > garbage, which becomes available once the garbage is collected. > > Thanks, > Shawn >
