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From:Ananda Kumar Date:March 26 2010 4:20pm
Subject:Re: MySQL Slave is almost 1 day behind
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Also,
run "SHOW PROCESSLIST", to see what sql's are running on slave.
This will give u any idea if any huge dml  was run on master and its getting
sync'd with slave.

regards
anandkl

On Fri, Mar 26, 2010 at 8:25 PM, Jim Lyons <jlyons4435@stripped> wrote:

> A few things to keep in mind:
>
> 1: the master may have several threads feeding into the binlog at a time,
> but a slave only executes in a single thread.  Are you throwing more stuff
> at the slave in multiple mysql threads?
>
> 2: is there something else going on with the slave box?  some big backup or
> gzip or something that would chew up cycles?  any big mysql query or update
> going on?
>
> 3: have you checked the disks on your slave.  Whenever I notice a slave
> falling behind for an extended period of time, I ask the sys admins to
> check
> the disk drives - if you're using some kind of RAID, they can become
> degraded.
>
> 4: you might also check the slave's mysql error log to see if there's any
> hint there.
>
>
>
>
>
> On Fri, Mar 26, 2010 at 9:45 AM, Steven Staples <sstaples@stripped> wrote:
>
> > Good day :)
> >
> > We've had our master/slave server running for a while now, and just
> > yesterday, we started getting behind.
> > Not entirely sure what happened, but it is getting further and furhter
> > behind.
> >
> > (master server)
> > mysql> show master status\G
> > *************************** 1. row ***************************
> >            File: mysql-bin.000280
> >        Position: 58090245
> >    Binlog_Do_DB: admin_server,baf,freeradius,radius
> > Binlog_Ignore_DB:
> > 1 row in set (0.00 sec)
> >
> >
> > (slave server)
> > mysql> show slave status\G
> > *************************** 1. row ***************************
> >             Slave_IO_State: Waiting for master to send event
> >                Master_Host: 192.168.7.101
> >                Master_User: slave_user
> >                Master_Port: 3306
> >              Connect_Retry: 60
> >            Master_Log_File: mysql-bin.000280
> >        Read_Master_Log_Pos: 55208258
> >             Relay_Log_File: backup-relay-bin.000530
> >              Relay_Log_Pos: 96663109
> >      Relay_Master_Log_File: mysql-bin.000259
> >           Slave_IO_Running: Yes
> >          Slave_SQL_Running: Yes
> >            Replicate_Do_DB: admin_server,baf,freeradius,radius
> >        Replicate_Ignore_DB:
> >         Replicate_Do_Table:
> >     Replicate_Ignore_Table:
> >    Replicate_Wild_Do_Table:
> > Replicate_Wild_Ignore_Table:
> >                 Last_Errno: 0
> >                 Last_Error:
> >               Skip_Counter: 0
> >        Exec_Master_Log_Pos: 96662972
> >            Relay_Log_Space: 2211376614
> >            Until_Condition: None
> >             Until_Log_File:
> >              Until_Log_Pos: 0
> >         Master_SSL_Allowed: No
> >         Master_SSL_CA_File:
> >         Master_SSL_CA_Path:
> >            Master_SSL_Cert:
> >          Master_SSL_Cipher:
> >             Master_SSL_Key:
> >      Seconds_Behind_Master: 77473
> > 1 row in set (0.00 sec)
> >
> > Now, we are logging the freeradius packets into mysql, and like I said,
> it
> > has been running fine, up until yesterday.   Any idea how the slave would
> > get this far behind, and not be generating any errors?
> >
> > It is my understanding, that the slave only does update/insert/delete
> > queries, so even if there was a lot of "select" queries on the master,
> the
> > slave wouldn't see them.  We are not running any queries on the slave (it
> > was set up for backup purposes, so we could stop the slave and backup
> > completely), and we haven't done a backup on the slave in a couple of
> days
> > (yeah, i know... bad bad) so there is really no reason for this.
> >
> > Can anyone help/assist/point me in the right direction to figure out how
> to
> > catch the slave back up to the master?  The master is not being
> overloaded,
> > it is keeping up no problem, and the backup server is 8x the server than
> > the
> > application server, so it shoulnd't even be an i/o or cpu issue.
> >
> > Please help! :)
> >
> >
> > Thanks in advance
> > Steven Staples
> >
> >
> > --
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> >
> >
>
>
> --
> Jim Lyons
> Web developer / Database administrator
> http://www.weblyons.com
>

Thread
MySQL Slave is almost 1 day behindSteven Staples26 Mar
  • Re: MySQL Slave is almost 1 day behindJim Lyons26 Mar
    • Re: MySQL Slave is almost 1 day behindAnanda Kumar26 Mar