Forum .LRN Q&A: Re: Server recommend for dotLRN - with 80.000 users-

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Posted by Cato Kolås on
We have around 18000 registered users, but max unique logins during a fortnight is close to 10000.

Specs:
webserver (~.LRN 1.0/OACS 4.6.3):
dual Xeon CPU 2.8 GHz, 3 GB RAM (dell 2650)

oracleserver (8.1.7.3):
dual Xeon CPU 2.8 GHz, 4 GB RAM (dell 2650)

(Both also has hyperthreading turned on and a dedicated 1 Gbit network between the two)

On heavy loads we find that it's the oracleserver that has the highest load. I'm wondering if the is anything more to gain by tweaking the aolserver-config:

ns_param  maxconnections    50
ns_param  maxdropped        0
ns_param  maxthreads        50
ns_param  minthreads        10
ns_param  threadtimeout      120
...
ns_section ns/db/pool/pool1
ns_param  connections        6
...
ns_section ns/db/pool/pool2
ns_param  connections        16
...
ns_section ns/db/pool/pool3
ns_param  connections        5

Some pics:
http://elg.uib.no/~edpck/logins-week.gif
http://elg.uib.no/~edpck/load-week.gif (green: webserver, blue: oracleserver)

All feedback appreciated

Cheers

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Posted by Andrew Piskorski on
Cato, my guess is you have your AOLserver threadtimeout set much too low, which is worth experimenting with and changing.

Why do you have so many more connections in your 2nd database pool than in your first? That seems weird.

On both machines, leaving the P4 hyperthreading turned on is also probably a bad idea unless you have a kernel (Linux 2.6.x, I think) which distinguishes between real and virtual/hyperthread processors.

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Posted by Cato Kolås on
> Cato, my guess is you have your AOLserver threadtimeout set
> much too low, which is worth experimenting with and
> changing.

ok, will do. thx.

> Why do you have so many more connections in your 2nd
> database pool than in your first? That seems weird.

have turned on logging when pools are empty:
ns_param  WarnEmpty          true
- and based on the numbers of warnings tried to adjust the settings.

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Posted by Nima Mazloumi on
Hi Cato,
can you tell me what tool you use to log the load on the webserver and the database?

Greetings,
Nima

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Posted by Cato Kolås on
|Hi Cato,
|can you tell me what tool you use to log the load on the
|webserver and the database?

It's mrtg with a custom script to gather information about the load from the two machines (runs uptime via ssh connections and greps for the load).