parsing mysql's bullshit query log format with logstash

logstash-mysql-query-parse.md

parsing mysql query logs with logstash

The problem is that some lines in the file are missing timestamps when they aren't continuations of any previous line. It's dumb, really.

The mysql query log is seriously bullshit format, but nothing logstash can't unscrew.

The main goal here is to show how we can fix the 'missing timestamp' problem.

% ruby bin/logstash agent -e '
  input {
    stdin {
      type => "mysql-slowquery"
    }
  }
  filter {
    # mysql query logs sometimes are missing a timestamp
    # and use spaces instead (WTF), so merge timestampless events with the
    # previous event.
    multiline {
      what => previous
      pattern => "^\s"
    }

    # pull out the timestamp (like, "120707  0:40:34")
    grok { pattern => "^%{NUMBER:date} *%{NOTSPACE:time}" }

    # put the timestamp into a single field
    mutate { replace => [ "time", "%{date} %{time}" ] }

    # parse the timestamp, which could be one or two digits.
    date { time => [ "YYMMdd H:mm:ss", "YYMMdd HH:mm:ss" ] }

    # remove time/date fields only previously added for parsing.
    mutate { remove => [ "time", "date" ] }

    # Now split up the multiline again, which keeps the timestamp for all split
    # out events. The defaults here are fine as they split '@message' by '\n'
    split { }
  }

  output {
    stdout { debug => true }
  }
'

input

120707  0:40:34     4 Connect   root@localhost on
                    4 Query     select @@version_comment limit 1
120707  0:40:45     4 Query     select * from mysql.user
120707  0:41:18     5 Query     hello world

logstash output

The key thing to note here is that the 'select @@version_comment ...' event now has the same timestamp as the previous line.

{
  "@source"      => "stdin://carrera.databits.net/",
  "@tags"        => [
    [0] "multiline"
  ],
  "@fields"      => {
    "time" => "120707 0:40:34"
  },
  "@timestamp"   => "2012-07-07T04:40:34.000Z",
  "@source_host" => "carrera.databits.net",
  "@source_path" => "/",
  "@message"     => "120707  0:40:34     4 Connect   root@localhost on",
  "@type"        => "mysql-slowquery"
}
{
  "@source"      => "stdin://carrera.databits.net/",
  "@tags"        => [
    [0] "multiline"
  ],
  "@fields"      => {
    "time" => "120707 0:40:34"
  },
  "@timestamp"   => "2012-07-07T04:40:34.000Z",
  "@source_host" => "carrera.databits.net",
  "@source_path" => "/",
  "@message"     => "                    4 Query     select @@version_comment limit 1",
  "@type"        => "mysql-slowquery"
}
{
  "@source"      => "stdin://carrera.databits.net/",
  "@tags"        => [],
  "@fields"      => {
    "time" => "120707 0:40:45"
  },
  "@timestamp"   => "2012-07-07T04:40:45.000Z",
  "@source_host" => "carrera.databits.net",
  "@source_path" => "/",
  "@message"     => "120707  0:40:45     4 Query     select * from mysql.user",
  "@type"        => "mysql-slowquery"
}
{
  "@source"      => "stdin://carrera.databits.net/",
  "@tags"        => [],
  "@fields"      => {
    "time" => "120707 0:41:18"
  },
  "@timestamp"   => "2012-07-07T04:41:18.000Z",
  "@source_host" => "carrera.databits.net",
  "@source_path" => "/",
  "@message"     => "120707  0:41:18     5 Query     hello world",
  "@type"        => "mysql-slowquery"
}