Hi, On Friday 19 May 2006 17:12, sheeri kritzer wrote: > I've found that queries that take a long time cause lag time.
Yes, I know, especially on a busy server. The master handles multiple statements (connections) in parallel, but the slave processes them serially. My 4.1.10 setup does about 170 queries/second, of which about a third are update statements, and I hardly ever got a lag above approximately 900 seconds. > Replication on a slave has 2 threads -- one to retrieve stuff from the > logs, and another to actually run the DML queries. Therefore, while > one thread is stuck on a looooonnnnggg query, the other thread is > still gathering stuff from the master, and that causes lag times. > > The value you gave for seconds_behind_master is about 58 hours -- that > seems unusually high. What are you doing to flush logs, etc? Nothing special, just some updates on a single database. No flushing of logs... The strange thing is that the condition of extremely high lag lasts only a couple of seconds, and then tapers back very quickly to zero. Martijn > On 5/19/06, Martijn van den Burg <[EMAIL PROTECTED]> wrote: > > Hi, > > > > Recently I created a new replication set up with 5.0.18-standard-log on > > Solaris 8 (one master, one slave). > > > > Replication is running, but periodically (after a bunch of INSERT/UPDATE > > statements) there is a very large replication lag, with > > Seconds_Behind_Master values of 210000 and more. This situation lasts for > > a few seconds and then all is normal. > > > > What could be the cause? I never had this happen with 4.1.10. > > > > Apologies for cross-posting; the volume on the 'replication' list is so > > low that I feared there might be no answer ;) > > > > > > Regards, > > > > Martijn > > > > -- > > MySQL General Mailing List > > For list archives: http://lists.mysql.com/mysql > > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- </Martijn> -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
