At 05:10 PM 2/4/01 +0100, Boris wrote:
>160.000 hits are wanted, so I calculate 160.000 div 24 = approx 6666
>Hits a hour, div 60 = 111 Hits a minute, = 1,85 Hits per secound.
>
>lets round it up to 2 hits per secound. So I calculate now
>2 hits per second * 3 seconds for a client
>= 6 processes at the same time,
>
>is that correct?
My guess is that your hits are likely to bunch up at certain times, rather
than be spread out evenly (90% of the people behave similarly 90% of the
time). So you might wish to multiply by 5 or 10 (or whatever you pluck from
the air ;) ) to cater for peak load.
Why are you saying it takes 3 seconds for a client? If it's because the
client is slow, you can do something about that, but if it's because your
query takes 3 seconds then maybe some people here could help with your query.
>If so, how much is the memory requiremend? I have seen with "TOP" that
>pgsql requires 5000kb for a request, but it is used per client (new
processes
The minimum size varies depending on what platform it's running on.
The max seems to vaguely depend on the size of the result set. But usually
most of the mem is reclaimed after the query is finished, at least on my
system.
Just do some tests with your bigger queries.
I'd say go for 512MB RAM.
Coz, usually you can't add RAM during peak load, and if you can, it usually
means you have hardware where 1GB or more is minimum anyway ;).
And you might be able to stick half on another server (web+app) if
desperate :).
Cheerio,
Link.