List:Replication« Previous MessageNext Message »
From:Suresh Kuna Date:January 27 2010 4:33pm
Subject:Re: Replication Speed
View as plain text  
It is the size of the binlog that it uses for reading BTW.


2010/1/27 Miguel Araújo <noradone@stripped>

> 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
>
>
>


-- 
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