Hi, Thanks Adrien. With current JVM versions (Java 8 or Java 11), the garbage collector never gives back memory to the operating system, once it has allocated that. Due to now heavy usage of containers and similar techniques, there are efforts on the JVM front to change that: At least the G1 garbage collector (also IBM J9's collector and also the brand new Shenandoah, but not the good old CMS) gets a new feature to give back memory to the operating system to a certain amount if it is idle, starting with Java 12: https://openjdk.java.net/jeps/346
But that's still a tricky issue, because if you limit the size of allocated memory, the garbage collection needs to happen more often, which if you have enough reserved space, the GC has a more relaxed job. Uwe ----- Uwe Schindler Achterdiek 19, D-28357 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Adrien Grand <jpou...@gmail.com> > Sent: Thursday, April 4, 2019 10:00 AM > To: Lucene Users Mailing List <java-user@lucene.apache.org> > Subject: Re: Why does Lucene 7.4.0 commit() Increase Memory Usage x2 > > I think what you are experiencing is just due to how the JVM works: it > happily reserves memory to the operating system if it thinks it might > need it, and then it's reluctant to give it back because it assumes > that if it has needed so much memory in the past, it might need it > again in the future. If you don't want to JVM to use so much memory, > just pass a lower value of the maximum heap size. > > On Wed, Apr 3, 2019 at 4:11 PM thturk <tahatur...@hotmail.com> wrote: > > > > I have tried Java VisualVM too watch GC status per each commit and relase > > variables for Reader Writer Searcher. But as result GC working like in > > photo at below > > > <http://lucene.472066.n3.nabble.com/file/t494233/Ekran_Al%C4%B1nt%C4 > %B1s%C4%B1.png> > > After 16.40 I called GC manully but Heap size didnt decrease is it cos its > > take while to merge serment for lucene ? cos after a hour Memory Ussage > > Decreased around 3G it was 3.5G after add new 15k document. > > > > > > > > -- > > Sent from: http://lucene.472066.n3.nabble.com/Lucene-Java-Users- > f532864.html > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > -- > Adrien > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
