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From:Dathan Vance Pattishall Date:September 30 2003 6:36pm
Subject:RE: What are the effects of key_buffer on a dedicated slave [also]
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-->-----Original Message-----
-->From: Jeremy Zawodny [mailto:Jeremy@stripped]
-->Sent: Tuesday, September 30, 2003 11:24 AM
-->To: Dathan Vance Pattishall
-->Cc: mysql@stripped
-->Subject: Re: What are the effects of key_buffer on a dedicated slave
-->[also]
-->
-->On Tue, Sep 30, 2003 at 11:07:59AM -0700, Dathan Vance Pattishall
wrote:
-->>
-->> -->-----Original Message-----
-->> -->From: Jeremy Zawodny [mailto:Jeremy@stripped]
-->> -->Sent: Tuesday, September 30, 2003 10:23 AM
-->> -->To: Dathan Vance Pattishall
-->> -->Cc: mysql@stripped
-->> -->Subject: Re: What are the effects of key_buffer on a dedicated
slave
-->>
-->>
-->> -->Is that all your slave is doing?  Replicating from the master?
Are
-->> there
-->> -->no other queries being run against it?
-->> -->
-->>
-->> It takes 50% of all reads from the application the db supports.
-->
-->The first thing I'd do is figure how how well utilized the key buffer
-->is today.  Either grab a copy of mytop (it does it for you), or look
-->at SHOW STATUS to compute the percentage based on the ratio of
-->key_read_requests to key_reads.

Yes, I use a custom mytop (sent my patches in to you). In fact I'm
making a signed java applet to simulate mytop, just to be fancy ;) as
well as not having to ssh into a central box that can reach all my
servers.
-->
-->If you're already hitting the buffer 99% of the time, there's little
-->point in increasing the size.

I figured that but does it really matter on a dedicated slave handling
some reads, since there can never be parallel writes? I may be missing
the concept. My Goal is to speed up replication (3.23.57) so I can
upgrade to 4.0.15 once the master / slave is in-sync and find out if the
var key_buffer on a dedicated slave helps out significantly.

-->
-->Jeremy
-->--
-->Jeremy D. Zawodny     |  Perl, Web, MySQL, Linux Magazine, Yahoo!
--><Jeremy@stripped>  |  http://jeremy.zawodny.com/
-->
-->MySQL 4.0.15-Yahoo-SMP: up 16 days, processed 586,536,970 queries
-->(405/sec. avg)



Thread
What are the effects of key_buffer on a dedicated slaveDathan Vance Pattishall30 Sep
  • Re: What are the effects of key_buffer on a dedicated slaveJeremy Zawodny30 Sep
    • RE: What are the effects of key_buffer on a dedicated slaveDathan Vance Pattishall30 Sep
    • RE: What are the effects of key_buffer on a dedicated slave [also]Dathan Vance Pattishall30 Sep
      • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny30 Sep
        • RE: What are the effects of key_buffer on a dedicated slave [also]Dathan Vance Pattishall30 Sep
          • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny30 Sep
            • RE: What are the effects of key_buffer on a dedicated slave [also]Dathan Vance Pattishall30 Sep
              • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny30 Sep
                • Re: What are the effects of key_buffer on a dedicated slave [also]William R. Mussatto30 Sep
                  • Re: What are the effects of key_buffer on a dedicated slave [also]Jeremy Zawodny1 Oct
  • Re: What are the effects of key_buffer on a dedicated slaveDan Nelson30 Sep
    • RE: What are the effects of key_buffer on a dedicated slaveDathan Vance Pattishall30 Sep