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From:root Date:October 8 2002 2:58am
Subject:RE: .Optimize mySQL memory usage ? 41MB threads ??
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On Mon, 7 Oct 2002, Jon Shoberg wrote:

> Ok,
> 
> 	So how do I optimize memory usage?  Where to start ?
> 
> -Jon
> 
> -----Original Message-----
> From: Dan Nelson [mailto:dnelson@stripped] 
> Sent: Monday, October 07, 2002 9:16 PM
> To: Jon Shoberg
> Cc: mysql@stripped
> Subject: Re: .Optimize mySQL memory usage ? 41MB threads ??
> 
> In the last episode (Oct 07), Jon Shoberg said:
> > I have a small PHP website that gets a fair amount of traffic.  It's
> > a simple layout with two tables. I average about 50 concurrently open
> > apache sessions and 40 open mysql connections.  I am calling for
> > persistent connections from the mySQL/PHP API.
> > 
> > But here is the kicker.  Each mySQL thread takes about 41mb!! :(  Can
> > anyone point me to resources on optimizing mySQL's memory usage under
> > a moderate/heavy load?
> 
> Threads have no memory.  You're getting misled by Linuxes threads
> implementation, which displays each thread as if it were a separate
> process.  They actually share the same block of memory, which is why
> they're threads and not processes.
> 
> 

add 
set-variable = key_buffer=128M
to my.cnf file.

actually 128M should be the sum of all the index (*.MYI) files.
FYI - mysql only caches data read from indexes 

you can check innodb buffer usage or hit ratios  by running the 
innodb_monitor.


Thread
.Optimize mySQL memory usage ? 41MB threads ??Jon Shoberg8 Oct
  • Re: .Optimize mySQL memory usage ? 41MB threads ??Dan Nelson8 Oct
    • RE: .Optimize mySQL memory usage ? 41MB threads ??Jon Shoberg8 Oct
      • Re: .Optimize mySQL memory usage ? 41MB threads ??Dan Nelson8 Oct
      • RE: .Optimize mySQL memory usage ? 41MB threads ??root8 Oct