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[Launchpad Bug Tracker <1201316@xxxxxxxxxxxxxxxxxx>]

[Expired for neutron because there has been no activity for 60 days.]

** Changed in: neutron
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1201316

Title:
  Skewed time on one node results of flapping happiness of all agents

Status in OpenStack Neutron (virtual network service):
  Expired

Bug description:
  Description of problem:
  When one server has incorrect time, it causes all agents switching between XXX and :-) in the 
  watch -n1 quantum agent-list

  Version-Release number of selected component (if applicable):
  openstack-quantum-2013.1.2-4.el6ost.noarch

  How reproducible:
  (:, when the time is not 2013-07-15 07:57:27+00:00

  Steps to Reproduce:
  1. Have multiagent deployment
  2. date -s '2013-07-15 07:57:27+00:00' on one node

  
  Actual results:
  all agents flapping
  nothing in logs

  
  Expected results:
  one agent XXX
  WARNING about clock skew in logs

  Additional info:
  I think stack should compute median over the timestamps and XXX those agents which are some threshold away from the median.

  I don't think it would be good to use average, because average is
  prone to drift by outliers.

  Also, as Eoghan Glynn noted, the algorithm could be made even smarter
  by recording agents drift and accept the agent if the long-time drift
  is same as the drifted timestamps. But then we would have problem
  after correcting the time on the drifted server.

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