# Confirming mlockall is working? **URL:** \ **Category:** Elasticsearch\ **Created:** [July 27, 2011, 4:46pm UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979 "2011-07-27T16:46:59Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ppearcy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ppearcy/32/980_2.png) [@ppearcy](https://discuss.elastic.co/u/ppearcy)\ **Post date:** [July 27, 2011, 4:46pm UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/1 "2011-07-27T16:46:59Z")
Hey, I've noticed some request time spikes with 0.16.2 that I hadn't observed with 0.14.2. I know that mlockall was critical in ensuring that GC didn't have much hit on response times. The docs state that: In order to see if this works or not, set the common.jna logging to DEBUG level. A solution to “Unknown mlockall error 0” can be to set ulimit -l unlimited. I have set common.jna logging to DEBUG, but don't see any messages logged from this class. Is that a confirmation that mlockall is working or should I expect to see something indicating that it is working? Thanks! Paul ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [July 27, 2011, 5:01pm UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/2 "2011-07-27T17:01:24Z")
Yes, if you don't see anything in the lock, then it should be working. On Wed, Jul 27, 2011 at 7:46 PM, ppearcy [ppearcy@gmail.com](mailto:ppearcy@gmail.com) wrote: > Hey, > I've noticed some request time spikes with 0.16.2 that I hadn't > observed with 0.14.2. I know that mlockall was critical in ensuring > that GC didn't have much hit on response times. > > The docs state that: > In order to see if this works or not, set the common.jna logging to > DEBUG level. A solution to “Unknown mlockall error 0” can be to set > ulimit -l unlimited. > > I have set common.jna logging to DEBUG, but don't see any messages > logged from this class. Is that a confirmation that mlockall is > working or should I expect to see something indicating that it is > working? > > Thanks! > Paul ---
**Author:** ![davrob](https://avatars.discourse-cdn.com/v4/letter/d/d78d45/32.png) [@davrob](https://discuss.elastic.co/u/davrob)\ **Post date:** [August 1, 2011, 11:56am UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/3 "2011-08-01T11:56:19Z")
Hi, I had the same worries about whether my mlockall setting was actually set, would it be possible to put a positive message in the logs like "mlockall now working"? Best Regards, David. On Jul 27, 6:01 pm, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > Yes, if you don't see anything in the lock, then it should be working. > > On Wed, Jul 27, 2011 at 7:46 PM, ppearcy [ppea...@gmail.com](mailto:ppea...@gmail.com) wrote: > > > Hey, > > I've noticed some request time spikes with 0.16.2 that I hadn't > > observed with 0.14.2. I know that mlockall was critical in ensuring > > that GC didn't have much hit on response times. > > > The docs state that: > > In order to see if this works or not, set the common.jna logging to > > DEBUG level. A solution to “Unknown mlockall error 0” can be to set > > ulimit -l unlimited. > > > I have set common.jna logging to DEBUG, but don't see any messages > > logged from this class. Is that a confirmation that mlockall is > > working or should I expect to see something indicating that it is > > working? > > > Thanks! > > Paul ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [August 1, 2011, 8:55pm UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/4 "2011-08-01T20:55:06Z")
Yes, I think it makes sense. Something like, if its explicitly set, then log a warn if its not working. Can you open an issue for it? On Mon, Aug 1, 2011 at 2:56 PM, davrob2 [daviroberts@gmail.com](mailto:daviroberts@gmail.com) wrote: > Hi, > > I had the same worries about whether my mlockall setting was actually > set, would it be possible to put a positive message in the logs like > "mlockall now working"? > > Best Regards, > > David. > > On Jul 27, 6:01 pm, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > > > Yes, if you don't see anything in the lock, then it should be working. > > > > On Wed, Jul 27, 2011 at 7:46 PM, ppearcy [ppea...@gmail.com](mailto:ppea...@gmail.com) wrote: > > > > > Hey, > > > I've noticed some request time spikes with 0.16.2 that I hadn't > > > observed with 0.14.2. I know that mlockall was critical in ensuring > > > that GC didn't have much hit on response times. > > > > > The docs state that: > > > In order to see if this works or not, set the common.jna logging to > > > DEBUG level. A solution to “Unknown mlockall error 0” can be to set > > > ulimit -l unlimited. > > > > > I have set common.jna logging to DEBUG, but don't see any messages > > > logged from this class. Is that a confirmation that mlockall is > > > working or should I expect to see something indicating that it is > > > working? > > > > > Thanks! > > > Paul ---
**Author:** ![davrob](https://avatars.discourse-cdn.com/v4/letter/d/d78d45/32.png) [@davrob](https://discuss.elastic.co/u/davrob)\ **Post date:** [August 2, 2011, 10:41am UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/5 "2011-08-02T10:41:34Z")
Issue raise here: [warn if mlockall is not working once enabled in settings (instead of debug logging) · Issue #1194 · elastic/elasticsearch · GitHub](https://github.com/elasticsearch/elasticsearch/issues/1194) thanks. On Aug 1, 9:55 pm, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > Yes, I think it makes sense. Something like, if its explicitly set, then log > a warn if its not working. Can you open an issue for it? > > On Mon, Aug 1, 2011 at 2:56 PM, davrob2 [davirobe...@gmail.com](mailto:davirobe...@gmail.com) wrote: > > > Hi, > > > I had the same worries about whether my mlockall setting was actually > > set, would it be possible to put a positive message in the logs like > > "mlockall now working"? > > > Best Regards, > > > David. > > > On Jul 27, 6:01 pm, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > > > > > Yes, if you don't see anything in the lock, then it should be working. > > > > On Wed, Jul 27, 2011 at 7:46 PM, ppearcy [ppea...@gmail.com](mailto:ppea...@gmail.com) wrote: > > > > > > > Hey, > > > > I've noticed some request time spikes with 0.16.2 that I hadn't > > > > observed with 0.14.2. I know that mlockall was critical in ensuring > > > > that GC didn't have much hit on response times. > > > > > The docs state that: > > > > In order to see if this works or not, set the common.jna logging to > > > > DEBUG level. A solution to “Unknown mlockall error 0” can be to set > > > > ulimit -l unlimited. > > > > > I have set common.jna logging to DEBUG, but don't see any messages > > > > logged from this class. Is that a confirmation that mlockall is > > > > working or should I expect to see something indicating that it is > > > > working? > > > > > Thanks! > > > > Paul ---
**Author:** ![Eran\_Eidinger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/eran_eidinger/32/44831_2.png) [@Eran\_Eidinger](https://discuss.elastic.co/u/Eran_Eidinger)\ **Post date:** [May 7, 2013, 3:09pm UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/6 "2013-05-07T15:09:44Z")
I have a noob question here. where (as in what file, is it etc/init.d/elasticsearch, or /etc/elasticsearch/elasticsearch.yml?) do I set the common.jna, and what is the syntax for setting it to debug? do I just set common.jna = DEBUG next to bootstrap.mlockall: true ? Where would I then follow the log to see this? would that be in /var/log/elasticsearch/elasticsearch.log? when would this appear there, when I start the service ("service elasticsearch start")? ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 2:37am UTC](https://discuss.elastic.co/t/confirming-mlockall-is-working/4979/7 "2017-07-06T02:37:56Z")
Closed on July 6, 2017, 2:37am UTC