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From:Matt Sturtz Date:December 30 2002 8:21pm
Subject:Re: Replication priority / speed
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Hello, Jeremy, et al--  Thanks for the reply before...  Further questions:


>> Is it possible to set either set the priority ('nice') of the Slave
>> thread down so it doesn't do that?
>
> The slave thread only?  No, not really.  You could nice MySQL when you
> start it up.  But I'm not sure how much effect (positive or negative)
> that'd have.

When I run "show [full] processlist", there's an "Id" column, but it
doesn't corrospond with the Unix PID of the process (on OS's that use a
seperate PID for each thread-- like Linux does)...  Is there any way
to(easilly) figure out which PID is handling the slave thread, so that I
might re-nice it after it's already been started up?

>> Or, alternatly, is there a way to limit the slave thread to only "X"
>> bin-log transactions per second?
>
> There is not.

Any plan to add this feature?  I would think it'd be useful...

> Are your updates already well optimized?  If you're doing enough work to
> cause noticeable speed problems, I'd double-check that if you
> haven't already.

MyTOP says our key efficiency is 97.35%, with an average of 1.24 q/sec (on
the master--  most queries are done directly on the slave, with only
updates happening on the master).  We've optimized things as best we can. 
The problem is our customers are allowed to bulk-load keywords into our
database, which causes about 4 large tables to be updated quite a bit. 
Whenever this happens, the slaves struggle to get caught back up...

Thanks again,

-Matt Sturtz-


Thread
Replication priority / speedMatt Sturtz26 Dec
  • Re: Replication priority / speedJeremy Zawodny27 Dec
    • Re: Replication priority / speedMatt Sturtz30 Dec
      • Re: Replication priority / speedJeremy Zawodny30 Dec
      • Re: Replication priority / speedDan Nelson30 Dec
        • Re: Replication priority / speedJeremy Zawodny30 Dec
  • Re: Replication priority / speedSimon K. Grabowski30 Dec
    • Re: Replication priority / speedMatt Sturtz31 Dec
  • Re: Replication priority / speedSimon Grabowski1 Jan