Closed as not planned
Description
When we stop our Discourse Docker container with docker stop app or service docker restart, it hangs. One or more runsv processes inside the container hang, consuming 100% CPU. top shows the CPU usage as "system" usage, so they are hung inside the kernel somewhere. Because of this, they can't be killed even with SIGKILL; we need to reboot the server.
This is a regression that showed up after we did some routine updates on the server (the ones that Ubuntu nags you to do). The packages that were upgraded included the kernel and Docker.
root@mail:~# uname -a
Linux mail.daystar.io 3.13.0-73-generic #116-Ubuntu SMP Fri Dec 4 15:31:30 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
root@mail:~# docker version
Client:
Version: 1.9.1
API version: 1.21
Go version: go1.4.3
Git commit: a34a1d5
Built: Fri Nov 20 17:56:04 UTC 2015
OS/Arch: linux/amd64
Server:
58CB
Version: 1.9.1
API version: 1.21
Go version: go1.4.3
Git commit: a34a1d5
Built: Fri Nov 20 17:56:04 UTC 2015
OS/Arch: linux/amd64
root@mail:~# docker info
Containers: 34
Images: 131
Server Version: 1.9.1
Storage Driver: aufs
Root Dir: /var/lib/docker/aufs
Backing Filesystem: extfs
Dirs: 230
Dirperm1 Supported: false
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 3.13.0-73-generic
Operating System: Ubuntu 14.04.3 LTS
CPUs: 12
Total Memory: 51.08 GiB
Name: mail.daystar.io
ID: 5PHA:QONL:U6TH:2IPO:AVNK:LMCW:R6XT:AVZZ:KNGC:T4TF:SX5S:5DHN
WARNING: No swap limit support