Martin is on point with newer faster chips (keeping the core counts in
check for licensing purposes).
You mention going to Linux, no slam against Windows but how will the
database perform on Linux with the same hardware?
Perhaps you can reduce the spikes by spreading the workload over a broader
time period or maybe some additional tuning of a few key problem queries
might get your CPU utilization at an acceptable threshold. I've seen too
many times where hardware upgrades are used as a band aid when some tuning
would have fixed the problem (I"m not saying this case applies). You may
have already done the tuning exercise or maybe this is a 3rd party
application for which you cannot tune anything.
For me a 40% utilization "most of the time" is not bad. You're utilizing
what you paid for and not leaving wasted CPU cycles. With the price of
Oracle licensing you really have to squeeze as much out of the server as
you can without penalizing the work to be done or more importantly the user
experience.
Alfredo
On Tue, Mar 21, 2017 at 3:27 PM, Martin Berger <martin.a.berger@xxxxxxxxx>
wrote:
Jeff,
You can argue with the wait time of a system with 2 CPUs and a load > 40%.
a nice graph is here:
https://www.researchgate.net/figure/235937645_fig8_Waiting-
time-on-queue-2-MMm-Graph-plotting-how-the-waiting-times-in-generic-units
Beside the theoretical background you can say, (about a 2 CPU system) at
40% utilization the response time is 50% higher than at minimal
utilization.
at 70% utilization the response time is 200% higher.
(years ago I read "Forecasting Oracle Performance" there are some
backgrounds about queueing available)
From a financial perspective I'd first check if upgrading the system with
faster CPUs will be much cheaper. RAM is not licensed at all, so more RAM
might help also - depending on your requirements.
good luck,
Martin
2017-03-21 21:07 GMT+01:00 Jeff Chirco <backseatdba@xxxxxxxxx>:
Hi everyone, I am working on trying to make a case that our production
database server needs some additional CPU's but was hoping you might be
able to give me some tips/suggestion that you've used to prove your case.
We are a smaller shop and so we currently only have a 2 CPU database
license and so the cost of doubling that plus all the packs and options we
have is not an easy thing to pass.
We currently running 11.2.0.4 on Windows but plans to move to Oracle
Linux this year and possibly 12c at that time.
We occasionally spike to 80-100% during the day but average around 40%
Thanks for any help.
Jeff
