Clients are over the internet. On Tue, Aug 25, 2020 at 3:25 AM Robert Engels <reng...@ix.netcom.com> wrote:
> The tcp protocol allows the connection to wait for hours. Go routines > stuck in wait do not burn CPU. Are the clients local or remote (over > internet)? > > On Aug 24, 2020, at 10:29 PM, Siddhesh Divekar <siddhesh.dive...@gmail.com> > wrote: > > > 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. > > -- -Siddhesh. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. 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