For experiment, I just changed my implementation to always dispose and recreate isolates after each JavaScript execution. I can easily reproduce a memory leak and my server process runs out of memory within an hour.
If I reuse the isolates, the server holds up for days executing the same set of requests. On Tuesday, December 13, 2016 at 10:35:40 AM UTC-8, Jane Chen wrote: > > Thanks Ben. I'm testing this on Linux. RH7 VM and Fedora 20. It's good > to know that you haven't seen this yourself. > I am seeing it when I dispose the isolate only when LowMemoryNotification > is insufficient to clear stuff. > > I am sure it's a leak not a fragmentation. This is what I see with sar -r: > > 01:00:02 PM 14200464 18580952 56.68 192932 4271524 31294112 76.01 14207024 > 3105796 156 > 01:10:01 PM 9128756 23652660 72.15 193988 4310140 37980896 92.25 19236772 > 3136272 136 > 01:20:02 PM 5579180 27202236 82.98 194800 4255556 41479544 100.75 22840464 > 3074896 144 > 01:30:02 PM 778656 32002760 97.62 175880 4218864 46678872 113.38 27647292 > 3056648 96 > 01:40:02 PM 251640 32529776 99.23 2372 581720 54419028 132.18 29623748 > 1665516 144 > 01:50:02 PM 405564 32375852 98.76 2516 499560 58361172 141.76 28903920 > 2223420 148 > --- process got killed and restarted --- > 02:00:02 PM 29851432 2929984 8.94 13224 696908 15415752 37.44 1416408 > 386944 0 > > I'll try with a different test to dispose and recreate isolates that don't > have issues with GC. I'll report back. > > On Tuesday, December 13, 2016 at 4:34:39 AM UTC-8, Ben Noordhuis wrote: >> >> On Tue, Dec 13, 2016 at 3:15 AM, Jane Chen <jxch...@gmail.com> wrote: >> > Related to this thread: >> > >> > https://groups.google.com/forum/#!topic/v8-users/deYE9pzK9b8 >> > >> > I am having some difficulty with garbage collection in v8 5.3. As a >> result, >> > I do the following after running a JavaScript request: >> > >> > 1) ContextDisposedNotification >> > 2) IdleNotificationDeadline >> > 3) If uncollected references still exist, LowMemoryNotification >> > 4) If uncollected references still exist, reset them in my code, then >> > dispose the isolate. >> > >> > Although this avoids a crash or memory corruption most of the time, I >> get a >> > memory leak and eventually run out of memory. >> > >> > The way I dispose an isolate is just by calling Isolate::Dispose(). Am >> I >> > missing anything? >> > >> > Conceptually, is the memory allocated and consumed in an isolate >> completely >> > freed when the isolate is disposed? Even when garbage collection is >> > incomplete in that isolate? >> > >> > Thanks in advance. >> >> It should release all resources, yes. I was looking into >> multi-isolate support in node.js a while ago and I didn't notice any >> memory leaks with 5.3 (IIRC, it might also have been 5.1.) >> >> Have you run your application through valgrind? Is it possible it's >> memory fragmentation instead of a memory leak? >> >> If you have multiple isolates making interleaved allocations, it's >> possible the address space fragments too much for a new isolate to >> reserve a sufficiently large chunk, even if some of the older isolates >> have been disposed of. >> >> That's normally only a problem with 32 bits builds although 64 bits >> Solaris/Illumos can be pretty terrible too. >> > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
