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.
