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From:Aveek Misra Date:May 25 2011 10:19am
Subject:MySQL server has gone away
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Hi,
   We are seeing intermittent errors of the type:

failed to execute "        SELECT * FROM cluster_info WHERE cluster = ?": MySQL server has
gone away

The error "MySQL server has gone away" is the error from the db handle. Can anyone give me
any pointers on why that happens? I looked up the documentation in MySQL docs and the most
common reason seems to be that it happens if the query size is very large or if there is a
timeout. None of them seems to be a probable cause. The "max_allowed_packet" on the server
is 16 MB and as can be seen in the query above, the query is very small and nowhere near
the size limit. We also have a timeout setting (wait_timeout) of 10 minutes and the above
query for us cannot possibly take that amount of time. In any case, given the same query,
it executes correctly 99% of time (so to speak). It fails intermittently with the above
error. What possibly could be the reason? I also looked at the max connections on the
server at that time (around ~80) and it is much less than the limit we have (limit is
1000). How can I extract more information when this happens? This error message sucks
since it does not tell me what exactly happened. The server version is 5.1.45.

Thanks
Aveek
Thread
MySQL server has gone awayAveek Misra25 May
  • Re: MySQL server has gone awayRik Wasmus25 May
    • Re: MySQL server has gone awayAveek Misra25 May
      • Re: MySQL server has gone awayPrabhat Kumar26 May
        • Re: MySQL server has gone awayClaudio Nanni27 May
          • Re: MySQL server has gone awayars k31 May
            • Re: MySQL server has gone awaychandrudba31 May
          • Re: MySQL server has gone awaychandrudba31 May