Re: MusicBrainz postgres performance issues

Roxanne Reid-Bennett <rox@xxxxxxxxxxx> · Sun, 15 Mar 2015 22:23:56 -0400



    On 3/15/2015 6:54 AM, Robert Kaye
      wrote:

    
      Hi!
      

      We at MusicBrainz have been having trouble with our
        Postgres install for the past few days. I’ve collected all the
        relevant information here:
      

        http://blog.musicbrainz.org/2015/03/15/postgres-troubles/
      

      If anyone could provide tips, suggestions or other
        relevant advice for what to poke at next, we would love it.
    
    Robert,

    
    Wow - You've engaged the wizards indeed.

    
    I haven't heard or seen anything that would answer my *second*
    question if faced with this (my first would have been "what
    changed")....

    
    What is the database actually trying to do when it spikes?  e.g.
    what queries are running ?

    Is there any pattern in the specific activity (exactly the same
    query, or same query different data, or even just same tables,
    and/or same users, same apps) when it spikes?

    
    I know from experience that well behaved queries can stop being well
    behaved if underlying data changes 

    
    and for the experts... what would a corrupt index do to memory
    usage?

    
    Roxanne