Analysis of excessive number of open docker socket files

Problem phenomenon

1、docker socket文件数量打开过多,超过65536时会导致整个docker服务不可用
2、出现超过docker打开文件数之前,docker上跑的业务均正常,可以正常通讯使用
3、docker exec inspect stop等命令针对问题主机的问题container无法正常使用,k8s的exec探活策略,此时返回的结果应该是直接卡死无返回,但k8s认为该container是活的
4、使用lsof统计socket文件,会导致重复统计,统计的文件打开数量会超出系统设置

problem causes

1. The actual business cluster has been deleted, but there is residual exec information

 1.1 在k8s里查看相关container集群已没有相关信息
 1.2 container对应的进程号信息,在系统层面看已全部回收,无相关进程
 1.3 进程查看时发现该container业务信息有残留exec的进程还活着
 1.4 kill -9 exec残留相关进程后,docker进程打开数就释放掉了
 1.5 此时node节点信息,一会ready 一会notready(kubectl get node -w)

  注: 查看日志知道出问题当天系统发起很频繁的OOM kill操作

2. Systemd problem

2.1 在k8s层面看相关业务集群均正常
2.2 进入问题节点获取信息:sider car的方式运行,pod中部分容器使用有问题
2.3 挑取问题container对应的集群信息后,登录正常的pod检查业务时,发现业务通讯均正常无异常信息
2.4 查看systemd-logind日志确认后发现是systemd的 session bug问题
2.5 执行systemctl daemon-reexec,后docker相关文件句柄均释放,恢复正常
2.6 systemd这个bug现象,ssh登录会慢,偶发失败现象
注:生产环境日志无debug信息,无法获取更多的信息,发生问题时无错误等级高的日志导致看上去正常,由于系统能正常使用,且系统相关load cpu mem指标看上去均正常,也无业务大量问题,未曾怀疑系统层面的问题。

3. The container becomes a zombie process

  3.1  在k8s层面看相关业务集群均正常
  3.2 进入问题节点获取信息:无法对问题container执行docker inspect exec相关命令
  3.3 排查进程后得知该该进程已变成僵尸进程
  3.4 进一步获取该节点的所有僵尸进程发现有大量的mysql僵尸进程
  3.5 对僵尸进程的父进程发起释放信号(kill -1 ppid)
  3.6 僵尸进程回收完后,docker相关文件句柄均释放,恢复正常
  3.7 node节点信息,一会ready 一会notready(kubectl get node -w)
 补充信息:
 SIGHUP        1       A     在控制终端上是挂起信号, 或者控制进程结束
 僵尸进程:一个进程使用fork创建子进程,如果子进程退出,而父进程并没有调用wait或waitpid获取子进程的状态信息,那么子进程的进程描述符仍然保存在系统中。这种进程称之为僵死进程。

unix提供了一种机制可以保证只要父进程想知道子进程结束时的状态信息, 就可以得到。这种机制就是: 在每个进程退出的时候,内核释放该进程所有的资源,包括打开的文件,占用的内存等。 但是仍然为其保留一定的信息(包括进程号the process ID,退出状态the termination status of the process,运行时间the amount of CPU time taken by the process等)。直到父进程通过wait / waitpid来取时才释放。 但这样就导致了问题,如果进程不调用wait / waitpid的话, 那么保留的那段信息就不会释放,其进程号就会一直被占用,但是系统所能使用的进程号是有限的,如果大量的产生僵死进程,将因为没有可用的进程号而导致系统不能产生新的进程. 此即为僵尸进程的危害,应当避免。

4. exec's own problems

4.1 针对生产及测试环境取到go的pprof debug信息
     a)可以看到goroutine主要集中在ContainerInspectCurrent信息查看
     b)内存消耗上主要集中在exec方法上
     c) 目前业务的探活策略主要使用exec方法

 4.2 exec代码确实有goroutine泄露问题

5. The rhel 7.6 systemd bug limits the number of open file handles of docker to 6w

This problem is a bug unique to the rhel 7.6 system. The systemd version below 240, the infinity set by docker does not take effect. The
systemd version below 242 has a dbus problem.

problem solved

Problem 1 solution steps

进入问题主机,找到问题container
for i in `docker ps | sed '1d'|awk '{print $1}'`; do echo $i; docker inspect $i -f '{{.State.Pid}}'; done
当执行到卡顿的container时,停止针对该container进行排查

找到卡顿的container对应长container_id号
docker ps --no-trunc|grep container_id

根据长container_id获取到container对应的进程号
cat /xxx/containers/long_container_id/config.v2.json|jq '.State.Pid'

确认该container对应的进程号已被系统回收
ps -aux |grep process_id

再次查询对应container_id残留在系统的exec进程信息
ps -aux |egrep 'PID|container_id'

杀掉残留进程信息
kill -9 pid

查看docker 相关socket是否已释放
ls  -l /proc/`pidof dockerd`/fd |wc -l

Problem 2 solution steps

查看systemd-logind服务是否存在session问题,如图
journalctl -u systemd-logind.service -f 内容含有Failed关键字
存在时执行命令恢复systemd服务
systemctl daemon-reexec
查看docker 相关socket是否已释放
ls  -l /proc/`pidof dockerd`/fd |wc -l
 见文章:https://blog.51cto.com/bingdian/2667503

Problem 3 solution steps

进入问题主机,找到问题container
for i in `docker ps | sed '1d'|awk '{print $1}'`; do echo $i; docker inspect $i -f '{{.State.Pid}}'; done
当执行到卡顿的container时,停止针对该container进行排查

找到卡顿的container对应长container_id号
docker ps --no-trunc|grep container_id

根据长container_id获取到container对应的进程号
cat /xx/containers/long_container_id/config.v2.json|jq '.State.Pid'

查看自身进程信息并进一步查看父进程信息,确认有一堆进程信息含有defunct
[root@xx ~]# ps -ef|egrep '43672|PID'
UID         PID   PPID  C STIME TTY          TIME CMD
root      43672  43617  0 Jan11 ?        00:00:00 [dumb-init]
root     111338  91631  0 09:07 pts/1    00:00:00 grep -E --color=auto 43672|PID

[root@xx ~]# ps -ef|grep 43617
root       3025  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root       3194  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       5432  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root       5682  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root       5747  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       6005  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root       6289  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root       6899  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       6913  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       7332  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root       7833  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root       7872  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root       8016  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       8368  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       9426  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root       9429  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       9882  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>

5、进一步查看系统的僵尸进程信息
[root@xx ~]# ps -A -ostat,ppid,pid,cmd |egrep -e '^[Zz]|PPID'
STAT   PPID    PID CMD
Zs    43617   3025 [entrypoint.sh] <defunct>
Z     43617   3194 [mysql] <defunct>
Z     43617   5432 [mysql] <defunct>
Zs    43617   5682 [entrypoint.sh] <defunct>
Z     43617   5747 [mysql] <defunct>
Z     43617   6005 [mysql] <defunct>
Z     43617   6289 [mysql] <defunct>
Z     43617   6899 [mysql] <defunct>
Z     43617   6913 [mysql] <defunct>
Z     43617   7332 [mysql] <defunct>
Zs    43617   7833 [entrypoint.sh] <defunct>
Z     43617   7872 [mysql] <defunct>
Z     43617   8016 [mysql] <defunct>
Z     43617   8368 [mysql] <defunct>
Z     43617   9426 [mysql] <defunct>
Z     43617   9429 [mysql] <defunct>
Z     43617   9882 [mysql] <defunct>
Zs    43617  10458 [entrypoint.sh] <defunct>
Z     43617  10884 [mysql] <defunct>
Z     43617  12012 [mysql] <defunct>
Z     43617  12861 [mysql] <defunct>

对僵尸进程的父进程发起回收信号,并查看执行后的僵尸进程信息
[root@xx ~]#kill -1 43617
[root@xx ~]# ps -A -ostat,ppid,pid,cmd |egrep -e '^[Zz]|PPID'
STAT   PPID    PID CMD
Z     16643  16778 [sh] <defunct>
S+    91631  16798 grep -E --color=auto -e ^[Zz]|PPID
Z     38096  63216 [vnetd] <defunct>

查看docker 相关socket是否已释放
[root@xx ~]# ls -l /proc/`pidof dockerd`/fd |wc -l
3336

Problem 4 solution steps

更新runc代码:对应v1.0.0-rc10 是已修复的,docker 18.09.6对应的runc版本是v1.0.0-rc6+dev

Problem 5 solution steps

1、内存处理,增加docker的文件打开数与系统级别一致
 prlimit -p `pidof dockerd` --nofile=1000000
2、确认dockerd进程打开数是否更新
grep 'Max open files' /proc/`pidof dockerd`/limits
3、变更docker 配置 
sed -i 's/LimitNOFILE=infinity/LimitNOFILE=1000000/g' /usr/lib/systemd/system/docker.service
4、daemon-reload加载docker配置
 systemctl daemon-reload

5、过滤docker配置是否变更
grep LimitNOFILE=1000000 /usr/lib/systemd/system/docker.service
该更新变更完成后,当docker服务重启后docker打开文件数会变成1000000

Detailed troubleshooting process

docker层面
版本信息
docker 版本v18.09.6
containerd 版本 v1.2.5     
runc版本v1.0.0-rc6+dev

Specific analysis steps

  1. Analysis based on log records
    # grep semacquire xxxx-go.debug  -c
    20932
    # grep '/go/src/github.com/' xxxx-go.debug |awk '{print $1}'|sort |uniq -c |sort -nrk1|more
    20648 /go/src/github.com/docker/docker/vendor/github.com/gorilla/mux/mux.go:103
    20648 /go/src/github.com/docker/docker/pkg/authorization/middleware.go:59
    20648 /go/src/github.com/docker/docker/api/server/server.go:141
    20648 /go/src/github.com/docker/docker/api/server/middleware/version.go:62
    20648 /go/src/github.com/docker/docker/api/server/middleware/experimental.go:26
    20647 /go/src/github.com/docker/docker/api/server/router_swapper.go:29
    20631 /go/src/github.com/docker/docker/daemon/inspect.go:29
    20631 /go/src/github.com/docker/docker/api/server/router/container/inspect.go:15
    20631 /go/src/github.com/docker/docker/api/server/router/container/container.go:39
    20615 /go/src/github.com/docker/docker/daemon/inspect.go:40
    312 /go/src/github.com/docker/docker/pkg/pools/pools.go:81

    1.1# A completed call chain log

    goroutine 205103020 [semacquire, 3893 minutes]:
    sync.runtime_SemacquireMutex(0xc422bfad04, 0x0)
        /usr/local/go/src/runtime/sema.go:71 +0x3f
    sync.(*Mutex).Lock(0xc422bfad00)
        /usr/local/go/src/sync/mutex.go:134 +0x10a
    github.com/docker/docker/daemon.(*Daemon).ContainerInspectCurrent(0xc420a941e0, 0xc45e94fdd6, 0x40, 0x0, 0xc442f97d00, 0xc442f97d40, 0xc453cd7920)
        /go/src/github.com/docker/docker/daemon/inspect.go:40 +0x8e
    github.com/docker/docker/daemon.(*Daemon).ContainerInspect(0xc420a941e0, 0xc45e94fdd6, 0x40, 0x0, 0xc45e94fdc6, 0x4, 0x555fc229de40, 0xc45f604801, 0xc465e24c60, 0xc45f6047c8)
        /go/src/github.com/docker/docker/daemon/inspect.go:29 +0x11d
    github.com/docker/docker/api/server/router/container.(*containerRouter).getContainersByName(0xc420c3fc00, 0x555fc26c8940, 0xc458c5bdd0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200, 0xc458c5bd40, 0x555fc1a389ba, 0x5)
        /go/src/github.com/docker/docker/api/server/router/container/inspect.go:15 +0x119
    github.com/docker/docker/api/server/router/container.(*containerRouter).(github.com/docker/docker/api/server/router/container.getContainersByName)-fm(0x555fc26c8940, 0xc458c5bdd0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200, 0xc458c5bd40, 0x555fc0576bac, 0x555fc2504880)
        /go/src/github.com/docker/docker/api/server/router/container/container.go:39 +0x6b
    github.com/docker/docker/api/server/middleware.ExperimentalMiddleware.WrapHandler.func1(0x555fc26c8940, 0xc458c5bdd0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200, 0xc458c5bd40, 0x555fc26c8940, 0xc458c5bdd0)
        /go/src/github.com/docker/docker/api/server/middleware/experimental.go:26 +0xda
    github.com/docker/docker/api/server/middleware.VersionMiddleware.WrapHandler.func1(0x555fc26c8940, 0xc458c5bda0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200, 0xc458c5bd40, 0x0, 0xc45f604a58)
        /go/src/github.com/docker/docker/api/server/middleware/version.go:62 +0x401
    github.com/docker/docker/pkg/authorization.(*Middleware).WrapHandler.func1(0x555fc26c8940, 0xc458c5bda0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200, 0xc458c5bd40, 0x555fc26c8940, 0xc458c5bda0)
        /go/src/github.com/docker/docker/pkg/authorization/middleware.go:59 +0x7ab
    github.com/docker/docker/api/server.(*Server).makeHTTPHandler.func1(0x555fc26c6d40, 0xc457b16380, 0xc467418200)
        /go/src/github.com/docker/docker/api/server/server.go:141 +0x19a
    net/http.HandlerFunc.ServeHTTP(0xc420ce8700, 0x555fc26c6d40, 0xc457b16380, 0xc467418200)
        /usr/local/go/src/net/http/server.go:1947 +0x46
    github.com/docker/docker/vendor/github.com/gorilla/mux.(*Router).ServeHTTP(0xc420c88cd0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200)
        /go/src/github.com/docker/docker/vendor/github.com/gorilla/mux/mux.go:103 +0x228
    github.com/docker/docker/api/server.(*routerSwapper).ServeHTTP(0xc420c7c050, 0x555fc26c6d40, 0xc457b16380, 0xc467418200)
        /go/src/github.com/docker/docker/api/server/router_swapper.go:29 +0x72
    net/http.serverHandler.ServeHTTP(0xc420a860d0, 0x555fc26c6d40, 0xc457b16380, 0xc467418200)
        /usr/local/go/src/net/http/server.go:2697 +0xbe
    net/http.(*conn).serve(0xc45f8b7400, 0x555fc26c8880, 0xc461eddb40)
        /usr/local/go/src/net/http/server.go:1830 +0x653
    created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:2798 +0x27d

1.2 According to the txt log, the problem occurred in this method, but the whole method is basically a memory operation; except that the meta information is read from the file in the overlay, if there is a problem, it should be a large-scale problem The entire docker service should be unusable, and the output of the docker command was normal at that time

func (daemon *Daemon) ContainerInspectCurrent(name string, size bool) (*types.ContainerJSON, error) {
    container.Lock() //40行发生semacquire(阻塞)

// ContainerInspectCurrent returns low-level information about a
// container in a most recent api version.
func (daemon *Daemon) ContainerInspectCurrent(name string, size bool) (*types.ContainerJSON, error) {
   container, err := daemon.GetContainer(name)
   if err != nil {
      return nil, err
   }

   container.Lock()
/*
getInspectData从内存获取container数据
*/
   base, err := daemon.getInspectData(container)
   if err != nil {
      container.Unlock()//当获取InspectData失败时释放锁
      return nil, err 
   }

/* --  获取内存中的网络数据,也不会导致阻塞* -- /
   apiNetworks := make(map[string]*networktypes.EndpointSettings)
   for name, epConf := range container.NetworkSettings.Networks {
      if epConf.EndpointSettings != nil {
         // We must make a copy of this pointer object otherwise it can race with other operations
         apiNetworks[name] = epConf.EndpointSettings.Copy()
      }
   }

   mountPoints := container.GetMountPoints()
   networkSettings := &types.NetworkSettings{
      NetworkSettingsBase: types.NetworkSettingsBase{
         Bridge:                 container.NetworkSettings.Bridge,
         SandboxID:              container.NetworkSettings.SandboxID,
         HairpinMode:            container.NetworkSettings.HairpinMode,
         LinkLocalIPv6Address:   container.NetworkSettings.LinkLocalIPv6Address,
         LinkLocalIPv6PrefixLen: container.NetworkSettings.LinkLocalIPv6PrefixLen,
         SandboxKey:             container.NetworkSettings.SandboxKey,
         SecondaryIPAddresses:   container.NetworkSettings.SecondaryIPAddresses,
         SecondaryIPv6Addresses: container.NetworkSettings.SecondaryIPv6Addresses,
      },
      DefaultNetworkSettings: daemon.getDefaultNetworkSettings(container.NetworkSettings.Networks),
      Networks:               apiNetworks,
   }

   ports := make(nat.PortMap, len(container.NetworkSettings.Ports))
   for k, pm := range container.NetworkSettings.Ports {
      ports[k] = pm
   }
   networkSettings.NetworkSettingsBase.Ports = ports
/* --  获取内存中的网络数据,也不会导致阻塞* -- /
   container.Unlock()

   if size {
      sizeRw, sizeRootFs := daemon.imageService.GetContainerLayerSize(base.ID)
      base.SizeRw = &sizeRw
      base.SizeRootFs = &sizeRootFs
   }

   return &types.ContainerJSON{
      ContainerJSONBase: base,
      Mounts:            mountPoints,
      Config:            container.Config,
      NetworkSettings:   networkSettings,
   }, nil
}

/*getInspectData*/ os命令,文件层面去获取相关信息,不会引发死锁问题;如果有问题整个overlayfs2都有问题,整台机的上的pod服务也应该是异常的。其余为内存层面的操作
func (daemon *Daemon) getInspectData(container *container.Container) (*types.ContainerJSONBase, error) {
    graphDriverData, err := container.RWLayer.Metadata()
    // If container is marked as Dead, the container's graphdriver metadata
    // could have been removed, it will cause error if we try to get the metadata,
    // we can ignore the error if the container is dead.
    if err != nil {
       if !container.Dead {
          return nil, errdefs.System(err)
       }
    } else {
       contJSONBase.GraphDriver.Data = graphDriverData
    }
  1. The debug file is further analyzed to
    view the top number of goroute, the big tribe is in getContainersByName
    (pprof) top
    Showing nodes accounting for 20652, 100% of 20656 total
    Dropped 117 nodes (cum <= 103)
    Showing top 10 nodes out of 54
      flat  flat%   sum%        cum   cum%
     20652   100%   100%      20652   100%  runtime.gopark
         0     0%   100%      17409 84.28%  github.com/docker/docker/api/server.(*Server).makeHTTPHandler.func1
         0     0%   100%      17409 84.28%  github.com/docker/docker/api/server.(*routerSwapper).ServeHTTP
         0     0%   100%      17409 84.28%  github.com/docker/docker/api/server/middleware.ExperimentalMiddleware.WrapHandler.func1
         0     0%   100%      17409 84.28%  github.com/docker/docker/api/server/middleware.VersionMiddleware.WrapHandler.func1
         0     0%   100%      16191 78.38%  github.com/docker/docker/api/server/router/container.(*containerRouter).(github.com/docker/docker/api/server/router/container.getContainersByName)-fm
         0     0%   100%        423  2.05%  github.com/docker/docker/api/server/router/container.(*containerRouter).(github.com/docker/docker/api/server/router/container.postContainerExecStart)-fm
         0     0%   100%      16191 78.38%  github.com/docker/docker/api/server/router/container.(*containerRouter).getContainersByName
         0     0%   100%        423  2.05%  github.com/docker/docker/api/server/router/container.(*containerRouter).postContainerExecStart
         0     0%   100%        791  3.83%  github.com/docker/docker/api/server/router/image.(*imageRouter).(github.com/docker/docker/api/server/router/image.deleteImages)-fm

    Further viewing is also concentrated in the ContainerInspect method

    (pprof) peek getContainersByName
    Showing nodes accounting for 20656, 100% of 20656 total
    ----------------------------------------------------------+-------------
      flat  flat%   sum%        cum   cum%   calls calls% + context
    ----------------------------------------------------------+-------------
                                             16191   100% |   github.com/docker/docker/api/server/middleware.ExperimentalMiddleware.WrapHandler.func1
         0     0%     0%      16191 78.38%                | github.com/docker/docker/api/server/router/container.(*containerRouter).(github.com/docker/docker/api/server/router/container.getContainersByName)-fm
                                             16191   100% |   github.com/docker/docker/api/server/router/container.(*containerRouter).getContainersByName
    ----------------------------------------------------------+-------------
                                             16191   100% |   github.com/docker/docker/api/server/router/container.(*containerRouter).(github.com/docker/docker/api/server/router/container.getContainersByName)-fm
         0     0%     0%      16191 78.38%                | github.com/docker/docker/api/server/router/container.(*containerRouter).getContainersByName
                                             16191   100% |   github.com/docker/docker/daemon.(*Daemon).ContainerInspect
    ----------------------------------------------------------+-------------
    (pprof)

    It is consistent with the information from the txt statistics obtained for the first time. The problem is on line 40 of inspect.go

    (pprof) list ContainerInspect
    Total: 20656
    ROUTINE ======================== github.com/docker/docker/daemon.(*Daemon).ContainerInspect in /go/src/github.com/docker/docker/daemon/inspect.go
         0      16191 (flat, cum) 78.38% of Total
         .          .     24:   case versions.LessThan(version, "1.20"):
         .          .     25:       return daemon.containerInspectPre120(name)
         .          .     26:   case versions.Equal(version, "1.20"):
         .          .     27:       return daemon.containerInspect120(name)
         .          .     28:   }
         .      16191     29:   return daemon.ContainerInspectCurrent(name, size)
         .          .     30:}
         .          .     31:
         .          .     32:// ContainerInspectCurrent returns low-level information about a
         .          .     33:// container in a most recent api version.
         .          .     34:func (daemon *Daemon) ContainerInspectCurrent(name string, size bool) (*types.ContainerJSON, error) {
    ROUTINE ======================== github.com/docker/docker/daemon.(*Daemon).ContainerInspectCurrent in /go/src/github.com/docker/docker/daemon/inspect.go
         0      16191 (flat, cum) 78.38% of Total
         .          .     35:   container, err := daemon.GetContainer(name)
         .          .     36:   if err != nil {
         .          .     37:       return nil, err
         .          .     38:   }
         .          .     39:
         .      16190     40:   container.Lock()
         .          .     41:
         .          1     42:   base, err := daemon.getInspectData(container)
         .          .     43:   if err != nil {
         .          .     44:       container.Unlock()
         .          .     45:       return nil, err
         .          .     46:   }
         .          .     47:
    (pprof)

    cpu data

    (pprof) top
    Showing nodes accounting for 50.58s, 95.80% of 52.80s total
    Dropped 213 nodes (cum <= 0.26s)
    Showing top 10 nodes out of 20
      flat  flat%   sum%        cum   cum%
    20.35s 38.54% 38.54%     21.06s 39.89%  runtime.heapBitsForObject
    11.97s 22.67% 61.21%     49.21s 93.20%  runtime.scanobject
     8.77s 16.61% 77.82%      8.77s 16.61%  runtime.markBits.isMarked (inline)
     3.89s  7.37% 85.19%      3.89s  7.37%  runtime.heapBits.bits (inline)
     2.95s  5.59% 90.78%     12.12s 22.95%  runtime.greyobject
     1.04s  1.97% 92.75%      1.69s  3.20%  runtime.sweepone
     0.75s  1.42% 94.17%     50.37s 95.40%  runtime.gcDrain
     0.43s  0.81% 94.98%      0.43s  0.81%  runtime.heapBitsForAddr (inline)
     0.29s  0.55% 95.53%      0.29s  0.55%  runtime.(*mspan).base (inline)
     0.14s  0.27% 95.80%      0.52s  0.98%  runtime.(*mspan).sweep

    The main time is still in the runtime.scanobject method

    (pprof) peek heapBitsForObject
    Showing nodes accounting for 52.80s, 100% of 52.80s total
    ----------------------------------------------------------+-------------
      flat  flat%   sum%        cum   cum%   calls calls% + context
    ----------------------------------------------------------+-------------
                                            21.02s 99.81% |   runtime.scanobject
                                             0.02s 0.095% |   runtime.scanblock
                                             0.02s 0.095% |   runtime.wbBufFlush1
    20.35s 38.54% 38.54%     21.06s 39.89%                | runtime.heapBitsForObject
                                             0.42s  1.99% |   runtime.heapBitsForAddr (inline)
                                             0.29s  1.38% |   runtime.(*mspan).base (inline)
    ----------------------------------------------------------+-------------
    (pprof) peek scanobject
    Showing nodes accounting for 52.80s, 100% of 52.80s total
    ----------------------------------------------------------+-------------
      flat  flat%   sum%        cum   cum%   calls calls% + context
    ----------------------------------------------------------+-------------
                                            49.21s   100% |   runtime.gcDrain
    11.97s 22.67% 22.67%     49.21s 93.20%                | runtime.scanobject
                                            21.02s 42.71% |   runtime.heapBitsForObject
                                            12.12s 24.63% |   runtime.greyobject
                                             3.89s  7.90% |   runtime.heapBits.bits (inline)
                                             0.17s  0.35% |   runtime.heapBits.next (inline)
                                             0.03s 0.061% |   runtime.spanOfUnchecked (inline)
                                             0.01s  0.02% |   runtime.heapBitsForAddr (inline)
    ----------------------------------------------------------+-------------
    (pprof) list runtime.scanobject
    Total: 52.80s
    ROUTINE ======================== runtime.scanobject in /usr/local/go/src/runtime/mgcmark.go
    11.97s     49.21s (flat, cum) 93.20% of Total
         .          .   1180:       if obj != 0 && obj-b >= n {
         .          .   1181:           // Test if obj points into the Go heap and, if so,
     490ms      490ms   1182:           // mark the object.
         .          .   1183:           //
     230ms      230ms   1184:           // Note that it's possible for findObject to
         .          .   1185:           // fail if obj points to a just-allocated heap
      50ms      220ms   1186:           // object because of a race with growing the
         .          .   1187:           // heap. In this case, we know the object was
         .          .   1188:           // just allocated and hence will be marked by
         .      3.89s   1189:           // allocation itself.
         .          .   1190:           if obj, span, objIndex := findObject(obj, b, i); obj != 0 {
         .          .   1191:               greyobject(obj, b, i, span, gcw, objIndex)
         .          .   1192:           }
         .          .   1193:       }
     750ms      750ms   1194:   }
         .          .   1195:   gcw.bytesMarked += uint64(n)
         .          .   1196:   gcw.scanWork += int64(i)
     300ms      300ms   1197:}
         .          .   1198:
         .          .   1199:// Shade the object if it isn't already.
         .          .   1200:// The object is not nil and known to be in the heap.
         .          .   1201:// Preemption must be disabled.
         .          .   1202://go:nowritebarrier
     1.19s      1.19s   1203:func shade(b uintptr) {
         .          .   1204:   if obj, span, objIndex := findObject(b, 0, 0); obj != 0 {
         .          .   1205:       gcw := &getg().m.p.ptr().gcw
         .          .   1206:       greyobject(obj, 0, 0, span, gcw, objIndex)
     5.82s      5.82s   1207:   }
         .          .   1208:}
     1.03s     22.05s   1209:
     850ms     12.97s   1210:// obj is the start of an object with mark mbits.

Memory data

(pprof) top
Showing nodes accounting for 28.52GB, 98.42% of 28.97GB total
Dropped 259 nodes (cum <= 0.14GB)
Showing top 10 nodes out of 38
      flat  flat%   sum%        cum   cum%
   18.19GB 62.79% 62.79%    18.19GB 62.79%  github.com/docker/docker/container.ReplaceOrAppendEnvValues
    4.57GB 15.77% 78.56%     7.30GB 25.19%  github.com/docker/docker/daemon/exec.NewConfig
    1.80GB  6.21% 84.77%     1.80GB  6.21%  github.com/docker/docker/container/stream.NewConfig (inline)
    0.93GB  3.21% 87.98%     0.93GB  3.21%  encoding/hex.EncodeToString
    0.91GB  3.15% 91.14%     0.91GB  3.15%  reflect.unsafe_NewArray
    0.86GB  2.98% 94.12%     0.86GB  2.98%  github.com/docker/docker/daemon/exec.(*Store).Add
    0.46GB  1.60% 95.72%    18.66GB 64.39%  github.com/docker/docker/container.(*Container).CreateDaemonEnvironment
    0.35GB  1.22% 96.94%     0.35GB  1.22%  encoding/json.(*decodeState).literalStore
    0.23GB   0.8% 97.74%     0.23GB   0.8%  github.com/docker/docker/pkg/ioutils.NopWriteCloser
    0.20GB  0.68% 98.42%     0.20GB  0.68%  github.com/docker/docker/daemon.(*Daemon).ProcessEvent

Mainly focus on exec

(pprof) peek exec
Showing nodes accounting for 29668.77MB, 100% of 29668.77MB total
----------------------------------------------------------+-------------
      flat  flat%   sum%        cum   cum%   calls calls% + context
----------------------------------------------------------+-------------
                                         7472.97MB   100% |   github.com/docker/docker/daemon.(*Daemon).ContainerExecCreate
 4677.83MB 15.77% 15.77%  7472.97MB 25.19%                | github.com/docker/docker/daemon/exec.NewConfig
                                         1843.08MB 24.66% |   github.com/docker/docker/container/stream.NewConfig (inline)
                                          952.06MB 12.74% |   github.com/docker/docker/pkg/stringid.GenerateNonCryptoID
----------------------------------------------------------+-------------
                                             884MB   100% |   github.com/docker/docker/daemon.(*Daemon).registerExecCommand
     884MB  2.98% 18.75%      884MB  2.98%                | github.com/docker/docker/daemon/exec.(*Store).Add
----------------------------------------------------------+-------------
                                               6MB   100% |   github.com/docker/docker/vendor/github.com/spf13/cobra.(*Command).ExecuteC
         0     0% 18.75%        6MB  0.02%                | github.com/docker/docker/vendor/github.com/spf13/cobra.(*Command).execute
                                               6MB   100% |   main.newDaemonCommand.func1
----------------------------------------------------------+-------------
(pprof) peek CreateDaemonEnvironment
Showing nodes accounting for 29668.77MB, 100% of 29668.77MB total
----------------------------------------------------------+-------------
      flat  flat%   sum%        cum   cum%   calls calls% + context
----------------------------------------------------------+-------------
                                        19105.09MB   100% |   github.com/docker/docker/daemon.(*Daemon).ContainerExecCreate
  475.51MB  1.60%  1.60% 19105.09MB 64.39%                | github.com/docker/docker/container.(*Container).CreateDaemonEnvironment
                                        18629.58MB 97.51% |   github.com/docker/docker/container.ReplaceOrAppendEnvValues
----------------------------------------------------------+-------------
(pprof) list exec
Total: 28.97GB
ROUTINE ======================== github.com/docker/docker/daemon/exec.(*Store).Add in /go/src/github.com/docker/docker/daemon/exec/exec.go
     884MB      884MB (flat, cum)  2.98% of Total
         .          .    113:}
         .          .    114:
         .          .    115:// Add adds a new exec configuration to the store.
         .          .    116:func (e *Store) Add(id string, Config *Config) {
         .          .    117:   e.Lock()
     884MB      884MB    118:   e.byID[id] = Config
         .          .    119:   e.Unlock()
         .          .    120:}
         .          .    121:
         .          .    122:// Get returns an exec configuration by its id.
         .          .    123:func (e *Store) Get(id string) *Config {
ROUTINE ======================== github.com/docker/docker/daemon/exec.NewConfig in /go/src/github.com/docker/docker/daemon/exec/exec.go
    4.57GB     7.30GB (flat, cum) 25.19% of Total
         .          .     37:}
         .          .     38:
         .          .     39:// NewConfig initializes the a new exec configuration
         .          .     40:func NewConfig() *Config {
         .          .     41:   return &Config{
         .   952.06MB     42:       ID:           stringid.GenerateNonCryptoID(),
         .     1.80GB     43:       StreamConfig: stream.NewConfig(),
    4.57GB     4.57GB     44:       Started:      make(chan struct{}),
         .          .     45:   }
         .          .     46:}
         .          .     47:
         .          .     48:type rio struct {
         .          .     49:   cio.IO
ROUTINE ======================== github.com/docker/docker/vendor/github.com/spf13/cobra.(*Command).execute in /go/src/github.com/docker/docker/vendor/github.com/spf13/cobra/command.go
         0        6MB (flat, cum)  0.02% of Total
         .          .    757:
         .          .    758:   if err := c.validateRequiredFlags(); err != nil {
         .          .    759:       return err
         .          .    760:   }
         .          .    761:   if c.RunE != nil {
         .        6MB    762:       if err := c.RunE(c, argWoFlags); err != nil {
         .          .    763:           return err
         .          .    764:       }
         .          .    765:   } else {
         .          .    766:       c.Run(c, argWoFlags)
         .          .    767:   }
(pprof)

Question 1 detailed troubleshooting process

 1 过滤异常container信息
    docker ps | grep -v NAME | awk '{print $1}' | while read cid; do echo $cid; docker inspect -f {{.State.Pid}} $cid; done
    出现卡死的情况停止:
    获得container id:aeb5e766d377
    获取该container的长ID: docker ps --no-trunc|grep aeb5e766d377
2 对异常container执行操作
    对该containerd执行exec inspect操作时均出现卡死无法执行情况
3 进入docker的存放目录获取该container id对应的进程,发现container的进程已不在
       cat /xxx/containers/contaner_id/config.v2.json|jq ".State.Pid" 
       6003
      ps -ef |grep 6003
4 查看k8s集群已没有相关pod devdoc255信息
       进一步查看整个集群也就是node09还剩下该pod了
5 查看message日志,在Jan 9号 09点的时候可以看到在oom打分时会出现该container对应的ID,内核并未对其进行oom操作,之后就没有出现过了 
6 根据conatiner的id串找到日志,查看log.json
这个containerd的 exec inspect stats 相关docker命令都无法正常执行

Problem 2 troubleshooting process

[root@xxx ~]# journalctl -u systemd-logind.service -f 含有Failed关键字,一般session问题

Question 3 detailed troubleshooting process

排除systemd-logind问题
[root@xxx ~]# journalctl -u systemd-logind.service -f
-- Logs begin at Mon 2021-01-04 15:11:30 CST. --
Jan 27 08:52:12 xxx systemd-logind[26590]: Removed session 6195.
Jan 27 08:52:13 xxx systemd-logind[26590]: Removed session 6196.
Jan 27 08:52:13 xxx systemd-logind[26590]: New session 6197 of user root.
Jan 27 08:52:14 xxx systemd-logind[26590]: Removed session 6197.
Jan 27 09:03:33 xxx systemd-logind[26590]: New session 6199 of user root.
Jan 27 09:03:33 xxx systemd-logind[26590]: New session 6200 of user root.
Jan 27 09:03:33 xxx systemd-logind[26590]: Removed session 6199.
Jan 27 09:03:33 xxx systemd-logind[26590]: Removed session 6200.
Jan 27 09:03:34 xxx systemd-logind[26590]: New session 6201 of user root.
Jan 27 09:03:34 xxx systemd-logind[26590]: Removed session 6201.

Confirm the problem phenomenon

[root@xxx ~]# ls -l /proc/`pidof dockerd`/fd |wc -l
22980

[root@xxx ~]# docker inspect 769397581e75
^C

Get process information

[root@xxx ~]# cat /xxx/containers/769397581e750250eb9636e430ab80bae9bbf5e785aec96cbea3cce145b6a0ce/config.v2.json |jq '.State.Pid'
43672
[root@xxx ~]# ps axu|grep 43672
root      29138  0.0  0.0 112660   968 pts/1    S+   09:06   0:00 grep --color=auto 43672
root      43672  0.0  0.0      0     0 ?        Ds   Jan11   0:00 [dumb-init]
[root@xxx ~]# ps -ef|egrep '43672|PID'
UID         PID   PPID  C STIME TTY          TIME CMD
root      43672  43617  0 Jan11 ?        00:00:00 [dumb-init]
root     111338  91631  0 09:07 pts/1    00:00:00 grep -E --color=auto 43672|PID

Further obtain the parent process information

[root@xxx ~]# ps -ef|grep 43617
root       3025  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root       3194  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       5432  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root       5682  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root       5747  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       6005  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root       6289  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root       6899  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       6913  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       7332  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root       7833  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root       7872  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root       8016  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       8368  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       9426  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root       9429  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root       9882  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      10458  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      10884  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      12012  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      12861  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      12913  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      13068  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      13591  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      13802  91631  0 09:07 pts/1    00:00:00 grep --color=auto 43617
root      14980  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      15272  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      15391  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      15623  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root      15793  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      16007  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      16363  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root      16517  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      16656  43617  0 Jan11 ?        00:00:00 [entrypoint.sh] <defunct>
root      16762  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      17210  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      18217  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      18750  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      21357  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      21500  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      21592  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      21857  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      21947  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      22317  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      22906  43617  0 Jan11 ?        00:00:00 [entrypoint.sh] <defunct>
root      23154  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      23172  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      23419  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      26152  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      26528  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      27291  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      27343  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root      27558  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      27658  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      27766  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      28815  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      29355  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      29454  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      30112  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      30910  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      31293  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      31560  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      34245  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      37588  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      38300  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      38355  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      38688  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      38811  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      38865  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      38984  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      38993  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      40319  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      41366  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      41890  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      42063  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      43075  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      43514  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      43617  37372  0 Jan11 ?        00:14:05 containerd-shim -namespace moby -workdir /var/lib/containerd/io.containerd.runtime.v1.linux/moby/769397581e750250eb9636e430ab80bae9bbf5e785aec96cbea3cce145b6a0ce -address /run/containerd/containerd.sock -containerd-binary /usr/bin/containerd -runtime-root /var/run/docker/runtime-runc
root      43672  43617  0 Jan11 ?        00:00:00 [dumb-init]
root      44174  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      44538  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      44699  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      45964  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      48683  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      49119  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      49751  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      51041  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      52101  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      52315  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      52478  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      53182  43617  0 Jan12 ?        00:00:00 [entrypoint.sh] <defunct>
root      53201  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      53726  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      53743  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root      54063  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      54884  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      64319  43617  0 Jan13 ?        00:00:00 [entrypoint.sh] <defunct>
root      64640  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      64700  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      64897  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      65128  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      66044  43617  0 Jan12 ?        00:00:00 [mysql] <defunct>
root      66143  43617  0 Jan11 ?        00:00:00 [mysql] <defunct>
root      67178  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>
root      68738  43617  0 Jan13 ?        00:00:00 [mysql] <defunct>

View system zombie process information

[root@xxx ~]# ps -A -ostat,ppid,pid,cmd |egrep -e '^[Zz]|PPID'
STAT   PPID    PID CMD
Zs    43617   3025 [entrypoint.sh] <defunct>
Z     43617   3194 [mysql] <defunct>
Z     43617   5432 [mysql] <defunct>
Zs    43617   5682 [entrypoint.sh] <defunct>
Z     43617   5747 [mysql] <defunct>
Z     43617   6005 [mysql] <defunct>
Z     43617   6289 [mysql] <defunct>
Z     43617   6899 [mysql] <defunct>
Z     43617   6913 [mysql] <defunct>
Z     43617   7332 [mysql] <defunct>
Zs    43617   7833 [entrypoint.sh] <defunct>
Z     43617   7872 [mysql] <defunct>
Z     43617   8016 [mysql] <defunct>
Z     43617   8368 [mysql] <defunct>
Z     43617   9426 [mysql] <defunct>
Z     43617   9429 [mysql] <defunct>
Z     43617   9882 [mysql] <defunct>
Zs    43617  10458 [entrypoint.sh] <defunct>
Z     43617  10884 [mysql] <defunct>
Z     43617  12012 [mysql] <defunct>
Z     43617  12861 [mysql] <defunct>
Z     43617  12913 [mysql] <defunct>
Zs    43617  13068 [entrypoint.sh] <defunct>
Z     43617  13591 [mysql] <defunct>
Z     43617  14980 [mysql] <defunct>
Z     43617  15272 [mysql] <defunct>
Zs    43617  15391 [entrypoint.sh] <defunct>
Zs    43617  15623 [entrypoint.sh] <defunct>
Z     43617  15793 [mysql] <defunct>
Z     43617  16007 [mysql] <defunct>
Zs    43617  16363 [entrypoint.sh] <defunct>
Z     43617  16517 [mysql] <defunct>
Zs    43617  16656 [entrypoint.sh] <defunct>
Z     43617  16762 [mysql] <defunct>
Z     43617  17210 [mysql] <defunct>
Zs    43617  18217 [entrypoint.sh] <defunct>
Z     43617  18750 [mysql] <defunct>
Z     43617  21357 [mysql] <defunct>
Z     43617  21500 [mysql] <defunct>
Z     43617  21592 [mysql] <defunct>
Z     43617  21857 [mysql] <defunct>
Z     43617  21947 [mysql] <defunct>
Z     43617  22317 [mysql] <defunct>
Zs    43617  22906 [entrypoint.sh] <defunct>
Z     43617  23154 [mysql] <defunct>
Zs    43617  23172 [entrypoint.sh] <defunct>
Z     43617  23419 [mysql] <defunct>
Z     43617  26152 [mysql] <defunct>
Z     43617  26528 [mysql] <defunct>
Zs    43617  27291 [entrypoint.sh] <defunct>
Zs    43617  27343 [entrypoint.sh] <defunct>
Z     43617  27558 [mysql] <defunct>
Z     43617  27658 [mysql] <defunct>
Z     43617  27766 [mysql] <defunct>
Z     43617  28815 [mysql] <defunct>
Z     43617  29355 [mysql] <defunct>
Z     43617  29454 [mysql] <defunct>
Z     43617  30112 [mysql] <defunct>
Z     43617  30910 [mysql] <defunct>
Z     43617  31293 [mysql] <defunct>
Z     43617  31560 [mysql] <defunct>
Z     43617  34245 [mysql] <defunct>
Z     43617  37588 [mysql] <defunct>
Zs    43617  38300 [entrypoint.sh] <defunct>
Zs    43617  38355 [entrypoint.sh] <defunct>
Z     43617  38688 [mysql] <defunct>
Z     43617  38811 [mysql] <defunct>
Z     43617  38865 [mysql] <defunct>
Z     43617  38984 [mysql] <defunct>
Z     43617  38993 [mysql] <defunct>
Z     43617  40319 [mysql] <defunct>
Z     43617  41366 [mysql] <defunct>
Z     43617  41890 [mysql] <defunct>
Z     43617  42063 [mysql] <defunct>
Zs    43617  43075 [entrypoint.sh] <defunct>
Z     43617  43514 [mysql] <defunct>
Zs    43617  44174 [entrypoint.sh] <defunct>
Z     43617  44538 [mysql] <defunct>
Z     43617  44699 [mysql] <defunct>
Z     43617  45964 [mysql] <defunct>
Z     43617  48683 [mysql] <defunct>
Z     43617  49119 [mysql] <defunct>
Z     43617  49751 [mysql] <defunct>
Z     43617  51041 [mysql] <defunct>
Z     43617  52101 [mysql] <defunct>
Zs    43617  52315 [entrypoint.sh] <defunct>
Z     43617  52478 [mysql] <defunct>
Zs    43617  53182 [entrypoint.sh] <defunct>
Z     43617  53201 [mysql] <defunct>
Z     43617  53726 [mysql] <defunct>
Zs    43617  53743 [entrypoint.sh] <defunct>
Z     43617  54063 [mysql] <defunct>
Z     43617  54884 [mysql] <defunct>
Z     38096  63216 [vnetd] <defunct>
S+    91631  63823 grep -E --color=auto -e ^[Zz]|PPID
Z     40381  63916 [mysqladmin] <defunct>
Zs    43617  64319 [entrypoint.sh] <defunct>
Z     43617  64640 [mysql] <defunct>
Z     43617  64700 [mysql] <defunct>
Z     43617  64897 [mysql] <defunct>
Z     43617  65128 [mysql] <defunct>

Deal with zombie processes and view the results

[root@xxx ~]#  kill -1 43617
[root@xxx ~]# ps -A -ostat,ppid,pid,cmd |egrep -e '^[Zz]|PPID'
STAT   PPID    PID CMD
Z     16643  16778 [sh] <defunct>
S+    91631  16798 grep -E --color=auto -e ^[Zz]|PPID
Z     38096  63216 [vnetd] <defunct>
[root@xxx ~]# ls -l /proc/`pidof dockerd`/fd |wc -l
3336

Troubleshoot supplementary
problems. The container log information is normal. No abnormal logs
. The container information process information is D or S. The
container process ns has access problems.

Reference materials:
https://askubuntu.com/questions/995517/what-is-the-function-of-kill-1-9-command
https://stackoverflow.com/questions/16944886/how-to-kill- zombie-process
https://serverfault.com/questions/792486/ssh-connection-takes-forever-to-initiate-stuck-at-pledge-network
https://cloud.tencent.com/developer/article/1636830

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Origin blog.51cto.com/bingdian/2667695