nova-novncproxy leaving behind zombie processes

Bug #1048703 reported by Joe T on 2012-09-10
This bug affects 11 people
Affects Status Importance Assigned to Milestone
OpenStack Compute (nova)
Sean Dague

Bug Description


As reported in this thread ( nova-novncproxy / novnc is leaving behind zombie processes after someone uses the VNC console:

$ pstree -Aapn

  |-python,109347 /usr/bin/nova-novncproxy --flagfile=/etc/nova/nova.conf --web ...
  | |-(python,95613)
  | |-(python,95624)
  | `-(python,95625)

$ ps aux | grep 95613
nova 95613 0.0 0.0 0 0 ? Z Sep08 0:00 [python] <defunct>

Please let me know if any further details or information is needed -- I'm not sure exactly what to collect.


Rafi Khardalian (rkhardalian) wrote :

I can confirm this one. We see it occurring in every deployment.

Vish Ishaya (vishvananda) wrote :

Can someone verify if this happens in devstack? Need to know if this needs to be investigated in folsom or if it is essex only.

Changed in nova:
status: New → Triaged
importance: Undecided → Medium
Joe T (joe-topjian-v) wrote :

I was able to reproduce this issue with a recent (as of today) install of devstack:

$ pstree -Aapn

  | |-bash,26889
  | | `-python,30368 ./utils/nova-novncproxy --config-file /etc/nova/nova.conf ...
  | | |-(python,31700)
  | | `-(python,31701)

$ ps aux | grep Z

ubuntu 31894 0.0 0.0 0 0 pts/12 Z+ 03:01 0:00 [python] <defunct>
ubuntu 31895 0.0 0.0 0 0 pts/12 Z+ 03:01 0:00 [python] <defunct>

Joe T (joe-topjian-v) wrote :

Oops, the last output was actually another set of zombie processes from a second test (for verification). For completeness, the output should have been:

$ ps aux | grep Z

ubuntu 31700 0.0 0.0 0 0 pts/12 Z+ 02:59 0:00 [python] <defunct>
ubuntu 31701 0.0 0.0 0 0 pts/12 Z+ 02:59 0:00 [python] <defunct>

Vish Ishaya (vishvananda) wrote :

Potential fix for this in websockify library:

currently devstack is pulling novnc directly so that will need to be changed to see if this fix works.

You could manually test by making the same fix in:


Joe T (joe-topjian-v) wrote :

Hi Vish,

Your comments sound specific to devstack. Do you think fixing the issue in Essex is possible? I'm more concerned about Essex.


Joe T (joe-topjian-v) wrote :


This is also a problem in Folsom. The patch that you linked to is included in the websockify package from the Ubuntu 12.04 folsom repo.


Claudio (claudio-enjoy) wrote :

same problem in grizzly ubuntu 12.04 with
  nova-novncproxy 1:2013.1-0ubuntu1~cloud0 OpenStack Compute - NoVNC proxy

in precise-updates/grizzly main

Matteo Panella (mpanella) wrote :

The problem persists in nova-novncproxy 1:2013.1.1-0ubuntu2~cloud0 from the Ubuntu Cloud Grizzly repo for precise.

Jason Dillaman (jdillaman) wrote :

Potential fix in the websockify library:

Joe T (joe-topjian-v) wrote :

I quickly tested the latest websockify module and, on first glance, it looks like it fixes this bug. Thanks, Jason!

Jiajun Liu (ljjjustin) on 2014-05-21
Changed in nova:
assignee: nobody → Jiajun Liu (ljjjustin)
Aimon Bustardo (aimonb) on 2014-06-02
no longer affects: centos


I have updated the Debian package to version 0.6.0+dfsg1-1. I guess Ubuntu users shall rebuild the package from the Debian source package, or use one of my (non-official) Ubuntu repository. Can anyone try this?

For Ubuntu trusty:

For Ubuntu precise:

For Debian Wheezy:

Note that I have no rights to update the official Ubuntu packages, I am only the poor Debian maintainer from which Ubuntu is just syncing from! :D

Change abandoned by Joe Gordon (<email address hidden>) on branch: master
Reason: Is this still active? Nothing has happened in a few months so marking as abandoned. Feel free to restore this.

Sean Dague (sdague) on 2014-09-19
no longer affects: nova/essex
Changed in nova:
assignee: Jiajun Liu (ljjjustin) → nobody
Sean Dague (sdague) wrote :

This is fixed by a requirements bump -

Changed in nova:
assignee: nobody → Sean Dague (sdague)
status: Triaged → In Progress

The review was abandoned..

Changed in nova:
status: In Progress → Confirmed
Deliang Fan (vanderliang) wrote :
Changed in nova:
status: Confirmed → Fix Released
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