Robert, We will do the profiling next time we hit the issue again & see what is happening. This was the first time we saw the issue & don't want to get rid of http2 advantages without making sure it's the actual culprit.
Do you think in the meanwhile we should do what the discussion below suggests anyways ? https://stackoverflow.com/questions/42238695/goroutine-in-io-wait-state-for-long-time On Mon, Aug 24, 2020 at 5:37 PM Robert Engels <reng...@ix.netcom.com> wrote: > I think it is too hard to tell with the limited information. It could be > exhausted connections or it could be thrashing (the claim of high cpu) > > I think you want to run profiling capture prior to hitting the stick state > - you should be able to detect what is happening. > > If the referenced issue is related I would assume you should be able to > connect by forcing http/1. > > You can also try disabling http/2 and see if your issue goes away. > > On Aug 24, 2020, at 6:15 PM, Siddhesh Divekar <siddhesh.dive...@gmail.com> > wrote: > > Hi Robert, > > Sorry I missed your earlier response. > > From what we saw our UI was blocked and since everything was unresponsive > we had to recover the system by sending sig abort. > > On Mon, Aug 24, 2020 at 4:11 PM Siddhesh Divekar < > siddhesh.dive...@gmail.com> wrote: > >> Looking at the no. of go routines we have does this apply to this issue ? >> https://github.com/golang/go/issues/27044 >> >> On Mon, Aug 24, 2020 at 12:54 PM Robert Engels <reng...@ix.netcom.com> >> wrote: >> >>> Go routines in a waiting state should not be consuming CPU. Are you >>> certain they are not in constant transition from waiting to processing - >>> this could show up as high CPU usage while everything looks blocks. >>> >>> I would use pprof - github.com/robaho/goanalyzer might be of assistance >>> here to see the actual work being done. >>> >>> On Aug 24, 2020, at 9:10 AM, Siddhesh Divekar < >>> siddhesh.dive...@gmail.com> wrote: >>> >>> >>> Hi Ian, >>> >>> Thanks for replying. >>> >>> We have a go server running which handles user requests & collects data >>> from various sources like gcp's cloud sql and big query. >>> We are using shopify's sarama library to do kafka operations. >>> >>> There are seeing lots of go routines in waiting state for several >>> minutes. >>> Over the period of time around 587 goroutines have been spun up. >>> >>> We see that two go routines are stuck on gcp big query and we are using >>> wait groups there. >>> However, it's not clear why that would cause all other go routines to >>> get hung & make cpu go high. >>> >>> goroutine 3332131 [semacquire, 79 minutes]: >>> sync.runtime_Semacquire(0xc001c4fcf8) >>> /usr/local/go/src/runtime/sema.go:56 +0x42 >>> sync.(*WaitGroup).Wait(0xc001c4fcf0) >>> /usr/local/go/src/sync/waitgroup.go:130 +0x64 >>> >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*InsMgr).runParallelQuery(0xc001b54d40, >>> 0xc002912c00, 0x330e1b0, 0xf, 0xc002912cf0, 0x3) >>> /builds/fusionio/fusion/controller/stats/ins_mgr.go:488 +0x1d7 >>> >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*InsMgr).GetMainUi(0xc001b54d40, >>> 0xc002912db8, 0xc001870e68, 0x746121, 0xc0010fcaf8, 0x17) >>> /builds/fusionio/fusion/controller/stats/ins_mgr.go:567 +0xa0d >>> >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*Prefetcher).fetchMainUiTeamInterval(0xc001b56780, >>> 0xc002356810, 0x24, 0x32f7b78, 0x5) >>> /builds/fusionio/fusion/controller/stats/prefetcher.go:77 +0xf2 >>> created by >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*Prefetcher).prefetchStats >>> /builds/fusionio/fusion/controller/stats/prefetcher.go:100 +0xd8 >>> >>> >>> goroutine 3332149 [semacquire, 79 minutes]: >>> sync.runtime_Semacquire(0xc0015ede48) >>> /usr/local/go/src/runtime/sema.go:56 +0x42 >>> sync.(*WaitGroup).Wait(0xc0015ede40) >>> /usr/local/go/src/sync/waitgroup.go:130 +0x64 >>> >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*InsMgr).runParallelQuery(0xc001b54d40, >>> 0xc00249dc00, 0x330e1b0, 0xf, 0xc00249dcf0, 0x3) >>> /builds/fusionio/fusion/controller/stats/ins_mgr.go:488 +0x1d7 >>> >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*InsMgr).GetMainUi(0xc001b54d40, >>> 0xc00249ddb8, 0xc003200668, 0xc00407a520, 0xc003200590, 0x46ee97) >>> /builds/fusionio/fusion/controller/stats/ins_mgr.go:567 +0xa0d >>> >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*Prefetcher).fetchMainUiTeamInterval(0xc001b56780, >>> 0xc002356ba0, 0x24, 0x32f7b78, 0x5) >>> /builds/fusionio/fusion/controller/stats/prefetcher.go:77 +0xf2 >>> created by >>> git.fusion.io/fusionio/fusion/controller.git/stats.(*Prefetcher).prefetchStats >>> /builds/fusionio/fusion/controller/stats/prefetcher.go:100 +0xd8 >>> >>> I found the link below which kind of co-relates to our scenario. >>> >>> https://stackoverflow.com/questions/42238695/goroutine-in-io-wait-state-for-long-time >>> >>> Most of the go routines in the backtrace are in a net/http package so >>> our suspicion is that above bug in our code might be causing that. >>> Even the bigquery is getting hung in net/http. >>> >>> We are using go version 1.13.8 & are running on gcp kubernetes cluster >>> on ubuntu 18.04 docker. >>> >>> go env >>> GO111MODULE="" >>> GOARCH="amd64" >>> GOBIN="" >>> GOCACHE="/root/.cache/go-build" >>> GOENV="/root/.config/go/env" >>> GOEXE="" >>> GOFLAGS="" >>> GOHOSTARCH="amd64" >>> GOHOSTOS="linux" >>> GONOPROXY="" >>> GONOSUMDB="" >>> GOOS="linux" >>> GOPATH="/root/go" >>> GOPRIVATE="" >>> GOPROXY="https://proxy.golang.org,direct"; >>> GOROOT="/usr/local/go" >>> GOSUMDB="sum.golang.org" >>> GOTMPDIR="" >>> GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64" >>> GCCGO="gccgo" >>> AR="ar" >>> CC="gcc" >>> CXX="g++" >>> CGO_ENABLED="1" >>> GOMOD="/builds/prosimoio/prosimo/pdash/go.mod" >>> CGO_CFLAGS="-g -O2" >>> CGO_CPPFLAGS="" >>> CGO_CXXFLAGS="-g -O2" >>> CGO_FFLAGS="-g -O2" >>> CGO_LDFLAGS="-g -O2" >>> PKG_CONFIG="pkg-config" >>> GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 >>> -fdebug-prefix-map=/tmp/go-build048009048=/tmp/go-build >>> -gno-record-gcc-switches" >>> >>> Let me know if any other information is needed. >>> >>> >>> On Sat, Aug 22, 2020 at 12:30 PM Ian Lance Taylor <i...@golang.org> >>> wrote: >>> >>>> On Sat, Aug 22, 2020 at 12:06 PM Siddhesh Divekar >>>> <siddhesh.dive...@gmail.com> wrote: >>>> > >>>> > We saw an issue with our process running in k8s on ubuntu 18.04. >>>> > Most of the go routines are stuck for several minutes in http/http2 >>>> net code. >>>> > >>>> > Have you seen similar issues ? >>>> > >>>> > goroutine 2800143 [select, 324 minutes]: >>>> net/http.(*persistConn).readLoop(0xc00187d440) >>>> /usr/local/go/src/net/http/transport.go:2032 +0x999 created by >>>> net/http.(*Transport).dialConn /usr/local/go/src/net/http/transport.go:1580 >>>> +0xb0d goroutine 2738894 [IO wait, 352 minutes]: >>>> internal/poll.runtime_pollWait(0x7f5b61b280c0, 0x72, 0xffffffffffffffff) >>>> /usr/local/go/src/runtime/netpoll.go:184 +0x55 >>>> internal/poll.(*pollDesc).wait(0xc0017e7e18, 0x72, 0x1000, 0x1000, >>>> 0xffffffffffffffff) /usr/local/go/src/internal/poll/fd_poll_runtime.go:87 >>>> +0x45 internal/poll.(*pollDesc).waitRead(...) >>>> /usr/local/go/src/internal/poll/fd_poll_runtime.go:92 >>>> internal/poll.(*FD).Read(0xc0017e7e00, 0xc0044a9000, 0x1000, 0x1000, 0x0, >>>> 0x0, 0x0) /usr/local/go/src/internal/poll/fd_unix.go:169 +0x1cf >>>> net.(*netFD).Read(0xc0017e7e00, 0xc0044a9000, 0x1000, 0x1000, 0xc0026359e8, >>>> 0x49d7fd, 0xc0017e7e00) /usr/local/go/src/net/fd_unix.go:202 +0x4f >>>> net.(*conn).Read(0xc0000db8b8, 0xc0044a9000, 0x1000, 0x1000, 0x0, 0x0, 0x0) >>>> /usr/local/go/src/net/net.go:184 +0x68 >>>> net/http.(*connReader).Read(0xc004a4fec0, 0xc0044a9000, 0x1000, 0x1000, >>>> 0x0, 0x0, 0x0) /usr/local/go/src/net/http/server.go:785 +0xf4 >>>> bufio.(*Reader).fill(0xc003f1a360) /usr/local/go/src/bufio/bufio.go:100 >>>> +0x103 bufio.(*Reader).Peek(0xc003f1a360, 0x4, 0x0, 0x0, 0x0, 0x0, >>>> 0xc002635ad0) /usr/local/go/src/bufio/bufio.go:138 +0x4f >>>> net/http.(*conn).readRequest(0xc0028e1d60, 0x393ed20, 0xc0024e9780, 0x0, >>>> 0x0, 0x0) /usr/local/go/src/net/http/server.go:962 +0xb3b >>>> net/http.(*conn).serve(0xc0028e1d60, 0x393ed20, 0xc0024e9780) >>>> /usr/local/go/src/net/http/server.go:1817 +0x6d4 created by >>>> net/http.(*Server).Serve /usr/local/go/src/net/http/server.go:2928 +0x384 >>>> > >>>> > Is there a know issue or something obvious from the backtrace here. >>>> >>>> It's entirely normal for goroutines to sit in pollWait if they are >>>> waiting for network I/O. There may be reasons why this is incorrect >>>> for your program, but you'll have to tell us those reasons. >>>> >>>> Also, along with those reasons, please tell us the version of Go and >>>> the exact environment that you are running. Thanks. >>>> >>>> Ian >>>> >>> >>> >>> -- >>> -Siddhesh. >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "golang-nuts" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to golang-nuts+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/CAMjfk%2BggC%2BwgwM_%2BM5ML0SKD3qJphCrif%3D4c2AqB9v6n%2Btw5Jw%40mail.gmail.com >>> <https://groups.google.com/d/msgid/golang-nuts/CAMjfk%2BggC%2BwgwM_%2BM5ML0SKD3qJphCrif%3D4c2AqB9v6n%2Btw5Jw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> <backtrace.txt> >>> >>> >> >> -- >> -Siddhesh. >> > > > -- > -Siddhesh. > > -- -Siddhesh. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. 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