[Orca-users] RE: FW: Capacity Planning

[Edwards, Mark]

Peter, Barry, Ken,

Many thanks for your assistance with this issue - What you have said
confirms my suspicions - that we are RAM bound. The application in question
also leaks - and it leaks like a sieve - there's anecdotal evidence of up to
100Mb an hour - so frequent application server restarts are currently an
operational feature. You don't want to ask... its a long story ...and not a
particularly pleasant one at that.

I'll also be investigating priority_paging as a matter_of_priority...

regards,

Mark



Mark P. Edwards 


-----Original Message-----
From: Peter Viertel [mailto:peter.viertel at it-action.com]
Sent: Thursday, 9 November 2000 18:19
To: orca-discuss at egroups.com
Subject: RE: [orca-discuss] FW: Capacity Planning


you need more RAM.

A happy system never scans. In the real world you can put up with about 200
scans/s. (per Adrian Cockcroft - Red Porsche book).

So first of all - audit you RAM usage, is the app leaking? or are the DBA's
taking too much shared memory and not leaving enough for the kernel.

If all else fails try more RAM in 2G steps until it goes away.

-----Original Message-----
From: Edwards, Mark [mailto:MarkE at pacificaccess.com.au]
Sent: Thursday, November 09, 2000 00:38
To: 'orca-discuss at egroups.com'
Subject: [orca-discuss] FW: Capacity Planning



> Hi,
> 
> I have been asked to produce a capaity plan for one of the platforms that
> our company runs, however the platform appears to be RAM bound at the
> moment. (Page Scan rates high and residency times low at times of peak
> demand). I am also noticing an potential issue with CPU usage. These
> servers have 6 CPU's on board and 5Gb RAM, however looking at the
> description you have given of the 'CPU usage' graph - particuarly where
> you say:
> 
> "If idle time is always low, check the number of processes in the run
> queue. More, or faster, CPUs may be necessary. If user CPU time is
> commonly less than system CPU there may be problems with the system set
> up."
> 
> I am noticing a consistent difference between the user and system CPU
> usage where the user CPU usage indeed appears to be less than the system
> CPU usage. Might this be additional evidence of a RAM bound state - high
> amounts of VM swappage going on?
> 
>  <<o___usr_pct,__sys_pct,__100_-_usr_pct_-_sys_pct-weekly.png>>  
> <<o___scanrate-daily.png>>  <<o___page_rstim-daily.png>> 
> 
> Please forgive me for asking this of you, but I am a tad new to capacity
> planning and graph interpretation, and looking for some assistance...
> 
> Mark
> 
> Mark P. Edwards 
> Pacific Access IT
> MarkE at pacificaccess.com.au
> +61 3 9281 3522
> +61 407 322 033
> 








-------------------------- eGroups Sponsor -------------------------~-~>
eLerts
It's Easy. It's Fun. Best of All, it's Free!
http://click.egroups.com/1/9699/4/_/576139/_/973809769/
---------------------------------------------------------------------_->