List:Replication« Previous MessageNext Message »
From:Miguel Araújo Date:January 27 2010 4:18pm
Subject:Re: Replication Speed
View as plain text  
Yes, the replication has been setup and it's running. Thanks for the clarification Suresh.
But, how can I read the values of read_master and exec_master, outside the mysql client?
By that I mean in a external application.
Thanks.

On Jan 27, 2010, at 4:04 PM, Suresh Kuna wrote:

> Hope the replication has been setup and running. We no need to bother about the which
> relay log the slave is reading. It depends on how much lag behind the current position of
> the read_master and exec_master.
> 
> Thanks
> Suresh Kuna
> MySQL DBA
> 
> 2010/1/27 Miguel Araújo <noradone@stripped>
> Suresh - Yes, I know that fact. That's why I will use virtual machines to do the
> tests and analyze the results.
> I hope you can help me with the binary logs doubt.
> Thanks.
> 
> Regards,
> Miguel Araújo
> 
> On Jan 27, 2010, at 3:03 PM, Suresh Kuna wrote:
> 
>> Miguel - It varies from machine to machine, network to network, depends on
> several factors like load, the sql you tested and more over all hardware components
> present in the server.
>> 
>> Thanks
>> Suresh Kuna
>> MySQL DBA 
>> 
>> 2010/1/27 Miguel Araújo <noradone@stripped>
>> I want to do do a tpcc benchark on a replicated database with a relatively large
> number of replicas.
>> 
>> The major timing issue is right what you've said "when an event will get
> *executed* on the slave", but I don't want to measure the occasional multisecond delay. As
> you said, replication is generally fast (in order of milliseconds), and my intention is to
> measure this delay in the order of milliseconds.
>> 
>> So, my approach is to read (each 10ms) the binary logs on master and each slave
> as the benchmark runs, and compare the position to finally calculate the delay time. And,
> like I've started questioning in this thread, my doubt is on what relay log to read.
>> 
>> Thanks.
>> 
>> Regards,
>> Miguel Araújo.
>> 
>> On Jan 27, 2010, at 2:35 PM, Johan De Meersman wrote:
>> 
>> > The event *arrives* pretty soon after - unless you have a flaky network,
> that's not really you should worry about.
>> >
>> > The major timing issue will be when an event will get *executed* on the
> slave, and the answer is: it varies. Events get executed sequentially on the slave, so
> although it will generally be fast (order of milliseconds), a huge update or other
> long-running query will block the queue until it finishes, and thus you could see the
> occasional multisecond delay.
>> >
>> > It all depends on your workload, though.
>> >
>> > 2010/1/27 Miguel Araújo <noradone@stripped>
>> > Hello.
>> >
>> > I want to measure replication speed for a great number of replicas. By that
> I mean how soon an event arrives at the slave after being logger to the master's binary
> log.
>> >
>> > So, I've started developing an application to read the replication logs in
> order to compare them (compare by time, the log position on the master node with the log
> position on the slave's). My first approach was to use the mysqlbinlog to get the log
> position, in the 'Master_Log_File'. But in the slave's the last position that the SQL
> thread has read and executed is the 'Relay_Log_Pos', right?
>> > I have to read the slave's relay log, in order to get the last position on
> the Master's log executed? And compare with the master's log?
>> >
>> > Thank you.
>> >
>> > Regards,
>> > Miguel Araújo
>> >
>> >
>> >
>> > --
>> > MySQL Replication Mailing List
>> > For list archives: http://lists.mysql.com/replication
>> > To unsubscribe:    http://lists.mysql.com/replication?unsub=1
>> >
>> >
>> >
>> >
>> > --
>> > Bier met grenadyn
>> > Is als mosterd by den wyn
>> > Sy die't drinkt, is eene kwezel
>> > Hy die't drinkt, is ras een ezel
>> 
>> 
>> 
>> 
>> -- 
>> Thanks
>> Suresh Kuna
>> MySQL DBA
> 
> 
> 
> 
> -- 
> Thanks
> Suresh Kuna
> MySQL DBA


Thread
Replication SpeedMiguel Araújo27 Jan
  • Re: Replication SpeedErwan Ben Souiden27 Jan
    • Re: Replication Speedsureshkumarilu27 Jan
  • Re: Replication SpeedMarcus Bointon27 Jan
  • Re: Replication SpeedJohan De Meersman27 Jan
    • Re: Replication SpeedMiguel Araújo27 Jan
      • Re: Replication SpeedSuresh Kuna27 Jan
        • Re: Replication SpeedMiguel Araújo27 Jan
          • Re: Replication SpeedSuresh Kuna27 Jan
            • Re: Replication SpeedMiguel Araújo27 Jan
              • Re: Replication SpeedSuresh Kuna27 Jan
                • Re: Replication SpeedRick James27 Jan
  • Re: Replication SpeedAndrej Pintar27 Jan
Re: Replication SpeedMiguel Araújo27 Jan