I ran with paranoid while observing the leak and got no messages from the ResourceLeakDetector.
Initial results from recycler maxCapacity of 0 are looking positive with respect to the leak. However, I did see a large spike of NIO memory allocated (1G) where the Netty 3 version of this app receiving similar traffic peaks at about 1/10th that. I'll let this run for a while and report back later with the full results. On Tue, Jul 19, 2016 at 2:59 PM, 'Norman Maurer' via Netty discussions < [email protected]> wrote: > Can you do me a favour and run with: > > -Dio.netty.recycler.maxCapacity=0 > > And let me know if you still see some leaks ? > > > > On 19 Jul 2016, at 20:50, Chris Conroy <[email protected]> wrote: > > 4.1.0.Final > > On Tue, Jul 19, 2016 at 2:48 PM, 'Norman Maurer' via Netty discussions < > [email protected]> wrote: > >> Are you using 4.0 or 4.1 ? >> >> On 19 Jul 2016, at 20:42, Chris Conroy <[email protected]> wrote: >> >> I have not been able to reproduce locally yet, but I do see it in a >> cluster that takes a lot of varied traffic. The leak detector has not fired >> for this under advanced. I will give paranoid a shot to be safe, but it's >> my understanding that the leak detection framework is more for dealing with >> pooled byte buf misuse, but in this case I am exclusively using unpooled >> heap byte bufs: these are just the socket direct byte bufs that appear to >> be leaking. >> >> I meant to add this earlier: The path to GC root goes: >> >> io.netty.buffer.ByteBufUtil$ThreadLocalUnsafeDirectByteBuf >> io.netty.util.Recycler$DefaultHandle >> io.netty.util.Recycler$DefaultHandle[] >> io.netty.util.Recycler#Stack >> java.lang.Object[] >> io.netty.util.internal.InternalThreadLocalMap >> ... (more thread local map refs up to java.lang.Thread) >> >> >> >> On Tuesday, July 19, 2016 at 2:17:25 PM UTC-4, Norman Maurer wrote: >>> >>> Can you provide a reproducer? Also did you try to run with paranoid leak >>> detection >>> >>> Am 19.07.2016 um 20:04 schrieb Chris Conroy <[email protected]>: >>> >>> Ah okay: I didn't see the calls to failFlushed since they occur above >>> the stanza I found suspicious. >>> >>> So, the above explanation is probably not correct. Still, I am seeing a >>> leak where DirectByteBufs are rooted to the recycler, and the speed at >>> which these buffers leak appears to be correlated with slow/partial readers. >>> >>> On Monday, July 18, 2016 at 4:36:31 PM UTC-4, Norman Maurer wrote: >>>> >>>> failFlushed(...) should be called to fail and release all flushed >>>> messages. >>>> >>>> Are you saying this not happens? >>>> >>>> Am 18.07.2016 um 22:02 schrieb Chris Conroy <[email protected]>: >>>> >>>> I’ve been trying to track down a NIO memory leak that occurs in a Netty >>>> application I am porting from Netty 3 to Netty 4. This leak does not occur >>>> in the Netty 3 version of the application. >>>> >>>> For now, I’m using only unpooled heap buffers in Netty 4, but NIO >>>> buffers do come into play for socket communication. >>>> >>>> I’ve captured a few heap dumps from affected instances, and in each it >>>> appears that the leaked DirectByteBuf java objects are rooted in an >>>> io.netty.util.Recycler. >>>> >>>> These buffers remain indefinitely: I can disable the application to >>>> drain traffic and force GCs, but the # of NIO buffers and NIO allocated >>>> space stays flat. >>>> >>>> The issue is likely related to slow readers. However, the leak persists >>>> long after all channels have been closed. >>>> >>>> I implemented a writability listener and the leak does appear to go >>>> away if I stop writing to a channel after it goes unwritable. This is good, >>>> but I’m still worried that this just makes the problem less likely since >>>> it’s still possible to write/flush and have pending data: writability just >>>> limits how much data will be buffered. >>>> >>>> Digging into ChannelOutBoundBuffer I see the following stanza in close: >>>> >>>> >>>> // Release all unflushed messages. >>>> try { >>>> Entry e = unflushedEntry; >>>> while (e != null) { >>>> // Just decrease; do not trigger any events via >>>> decrementPendingOutboundBytes() >>>> int size = e.pendingSize; >>>> TOTAL_PENDING_SIZE_UPDATER.addAndGet(this, -size); >>>> >>>> if (!e.cancelled) { >>>> ReferenceCountUtil.safeRelease(e.msg); >>>> safeFail(e.promise, cause); >>>> } >>>> e = e.recycleAndGetNext(); >>>> } >>>> } finally { >>>> inFail = false; >>>> } >>>> clearNioBuffers(); >>>> >>>> This seems a bit curious to me: why are flushed buffers not released >>>> here? Since the leak seems to be rooted in the Recycler, this could be the >>>> culprit…What do you think? >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Netty discussions" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/netty/CA%2B%3DgZKADssKFcs-WCc8%2Br2RWrvbgg3csaJPdcsXL_mCD5yG2bg%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/netty/CA%2B%3DgZKADssKFcs-WCc8%2Br2RWrvbgg3csaJPdcsXL_mCD5yG2bg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Netty discussions" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/netty/b66894c3-1e65-4235-9201-b4f1dca11a81%40googlegroups.com >>> <https://groups.google.com/d/msgid/netty/b66894c3-1e65-4235-9201-b4f1dca11a81%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Netty discussions" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/netty/e823494b-caf1-4b1f-b629-405bbdbf4c40%40googlegroups.com >> <https://groups.google.com/d/msgid/netty/e823494b-caf1-4b1f-b629-405bbdbf4c40%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "Netty discussions" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/netty/Ve4lnRvFXjM/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/netty/F788648D-2C4E-4031-BD2A-EFFAEED64BDC%40googlemail.com >> <https://groups.google.com/d/msgid/netty/F788648D-2C4E-4031-BD2A-EFFAEED64BDC%40googlemail.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > > -- > You received this message because you are subscribed to the Google Groups > "Netty discussions" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/netty/CA%2B%3DgZKAiQseAviHAkbE-eoybDWQsGY1ek6LtXkMCebcMd4WU4g%40mail.gmail.com > <https://groups.google.com/d/msgid/netty/CA%2B%3DgZKAiQseAviHAkbE-eoybDWQsGY1ek6LtXkMCebcMd4WU4g%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > > > -- > You received this message because you are subscribed to a topic in the > Google Groups "Netty discussions" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/netty/Ve4lnRvFXjM/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/netty/925935D9-92F1-4516-B9E9-524991BF053E%40googlemail.com > <https://groups.google.com/d/msgid/netty/925935D9-92F1-4516-B9E9-524991BF053E%40googlemail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Netty discussions" group. 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