On 22 Feb 2015 at 19:43:08, Aaron Hardy at AC ([email protected](mailto:[email protected])) wrote:
> Hi Vincent, > > Thanks for the follow-up. > > I never managed to track down the exact cause of the futex lock or > gettimeofday calls. My best guess is that it has something to do with XWiki > running on an Amazon EC2 instance. I didn't see the same kind of issues on a > local machine. I had another thread a few months ago where I asked if anyone > had successfully run XWiki on AWS, and it didn't seem like there was much > experience with that setup. > > My short term solution was just to double the RAM and throw it all at XWiki. > That seems to have mostly dealt with the stability issues (at least, the > instance rarely crashes under load), but under the hood I think it's still > performing much worse than it should be. > > Any ideas you have about what might be causing the issue, or any tips for > running XWiki on Amazon under reasonably high loads would be much > appreciated. Thanks for the information and indeed you could be right about the Amazon EC2 context for the futex problem. I don’t have any experience with running XWiki on Amazon EC2 so I cannot help much, sorry. Thanks -Vincent > Thanks, > > aaron > > > > On Fri, Feb 20, 2015 at 10:05 AM, > [email protected](mailto:[email protected]) wrote: > > Hi Aaron, > > > > Sorry you didn’t get any answer… > > > > Were you able to find out the problem and improve XWiki under load? > > > > Thanks > > -Vincent > > > > > > On 20 Sep 2014 at 06:52:10, Aaron Hardy at AC > > ([email protected](mailto:[email protected])(mailto:[email protected])) > > wrote: > > > > > Trying to track down the source of some persistent performance issues > > > under > > > load with 6.2 RC 1 (haven't had time to upgrade to 6.2 final yet). I'm > > > maxing out at about 30 or so users before dying on a system with 4GB of > > > RAM. > > > > > > The java interpreter is getting pegged to 100% of the CPU, and about 70% > > > of > > > the calls in the stack trace are futex lock errors. A good chunk of the > > > remainder are gettimeofday calls. > > > > > > Potentially useful info (sorry for formatting): > > > > > > % time seconds usecs/call calls errors syscall > > > ------ ----------- ----------- --------- --------- ---------------- > > > 72.75 5361.592109 45075 118947 14045 futex > > > 12.28 905.064191 466 1943354 gettimeofday > > > 4.83 356.110745 3709487 96 45 restart_syscall > > > 2.88 212.173358 836 253729 clock_gettime > > > 2.71 199.867690 8802 22706 recvfrom > > > 2.10 154.843342 37841 4092 poll > > > 1.14 84.282371 580 145307 130153 stat > > > > > > Any ideas? > > > > > > thanks, > > > > > > aaron > > > _______________________________________________ users mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/users
