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From:Claudio Nanni Date:March 9 2009 8:43pm
Subject:Re: mysql behaviour
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HI Miguel,
first everything in your status is related to 7079381seconds uptime, that is
81 days.

After that it depends on the activity, but It seems that yours is just a
feeling, not a fact.
You have a that a table si (re)opened 350 times per day that is nothing,
mysql caches table files descriptor and keeps tables ready to be used (64),
and the queries per second (Questions/Uptime) is not a big deal.
I would pay for having 169 slow queries in 81 days on my servers!
To understand which and why some queries are slow you need to analyze the
slow query log.
Try to issue a 'SHOW STATUS' and 'SHOW VARIABLES' command and post the
results.

Cheers
Claudio



2009/3/9 Miguel <mcm@stripped>

>  my worry is that the framework is running really slowly and I am trying to
> justify why...
>
> here, I can see a high number of Opens and questions when the sytem is not
> now being used by anybody... Is it normal to keep the tables opened? and
> have so many queries per second? and what about the slow queries?
>
> thank you very much,
> Miguel
>
> On Mon, 2009-03-09 at 18:31 +0100, Claudio Nanni wrote:
>
> It is really not enough for me to give an opinion but I do not see
> anything strange, what is your worry?
>
>
> Miguel wrote:
> > thank you Claudio, something that is messing me up is what folllows:
> >
> > Uptime: 7079381  Threads: 3  Questions: 776439788  Slow queries: 189
> > Opens: 27771  Flush tables: 1  Open tables: 64  Queries per second
> > avg: 109.676
> >
> > I am trying to optimize a django project. I am not familiar with this
> > framework but it seems it has a very very bad performance.
> >
> > Is it not normal the above results, isn't it?
> >
> >
> >
> >
> >
> > On Mon, 2009-03-09 at 14:00 +0100, Claudio Nanni wrote:
> >> Here is a very interesting reading for you!
> >>
> >> http://dev.mysql.com/doc/refman/5.0/en/table-cache.html
> >>
> >> Claudio
> >>
> >>
> >> 2009/3/8 Miguel <mcm@stripped <mailto:mcm@stripped
> <mcm@stripped>>>
> >>
> >> > Hello,
> >> >
> >> > I wanted to know how mysql behaves when accessing to its tables.
> >> > I have check the file descriptors and I could see different MYI and
> MYD
> >> > opened.
> >> >
> >> > mysqld  17638 mysql  125u   REG        8,4    124928
> >> > 83197 /usr/var/lib/mysql/xxxxxx.MYI
> >> > mysqld  17638 mysql  126u   REG        8,4   1186784
> >> > 83051 /usr/var/lib/mysql/yyyyy.MYD
> >> >
> >> > [...]
> >> >
> >> > my question is , must these files descriptors be closed after accesing
> >> > to the tables? or these files keep opening?
> >> >
> >> > thank you very much,
> >> > Miguel
> >> >
> >> >
> >>
>
>
>
>

Thread
mysql behaviourMiguel8 Mar
  • Re: mysql behaviourClaudio Nanni9 Mar
    • Re: mysql behaviourMiguel9 Mar
      • Re: mysql behaviourClaudio Nanni9 Mar
        • Re: mysql behaviourMiguel9 Mar
          • Re: mysql behaviourClaudio Nanni9 Mar
Re: mysql behaviourMiguel9 Mar
  • Re: mysql behaviourClaudio Nanni9 Mar
    • Re: mysql behaviourMiguel9 Mar
      • Re: mysql behaviourClaudio Nanni10 Mar
        • Re: mysql behaviourMiguel10 Mar
          • Re: mysql behaviourClaudio Nanni10 Mar