Changes between Version 12 and Version 13 of InstallationGuidelines/Cluster


Ignore:
Timestamp:
11/30/17 11:53:17 (4 years ago)
Author:
Dominic König
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • InstallationGuidelines/Cluster

    v12 v13  
    2727
    2828 - Server becomes suddenly unavailable for about 15 minutes, before returning to normal
    29 
    30 Observations:
    31 
    3229 - No signs of CPU/RAM saturation at the back-end (no signs of any back-end activity at all during the blackout)
    3330 - Instant recovery: server is immediately back to normal after the blackout (no secondary delays)
     
    3532 - None of the logs showing any irregularities - no errors, no strange requests/responses
    3633
    37 Critically:
     34Observations:
    3835
    3936 - Blackout length is constant (900sec), and doesn't seem to depend on request complexity
     
    4138 - Typically occurs after a period of lower traffic, at the moment when traffic increases again
    4239 - At least one of the workers had been inactive for a significant period of time (e.g. 4000+ seconds) before the hanging request
     40 - Provoking a uWSGI "harakiri" (by setting the timeout well below 900sec), the traceback often (not always) shows the worker hanging in {{{PQgetResult}}}/{{{poll}}}
    4341=== Reason ===
    4442There is a router between front- and back-end - which isn't the ideal configuration, of course, but normal in many clouds.