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Searcing for Processor "best practices"

 
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Rob Hussey
Advisor

Searcing for Processor "best practices"

We are running an RX7640 - HPUX 11.23 ( Upgrading to 11.31 shortly ) with Oracle 11R1 ( Upgrading to R2 shortly) ( Large DB )

I have heard that most places like to run at a 30% to 45% Processor utility rate, as prescribed by using top and taking the inverse of the idle value.

For the past 12 months, as well as the last peak volume, we have been averaging a utility of 21% of our processors. With this being said, it is my belief that we actually have more than the cost effective need of processors.

I am unable to locate any standards, white papers or “best practices” or the like to support my beliefs.

TIA,
- Rob
- Rob Hussey
14 REPLIES 14
Pete Randall
Outstanding Contributor

Re: Searcing for Processor "best practices"

This is definitely a "it depends" question.

Do you have any peak periods that require more processing power? Month-end processing? Billing cycles? If not, I would tend to agree that you have more than enough, but I surely wouldn't worry about it.

It's also possible that your upcoming upgrades may require more resources so keep that in mind.


Pete

Pete
Rob Hussey
Advisor

Re: Searcing for Processor "best practices"

We do have 3 weeks of the year we run a lot of code that I believe, is extremely poorly written and thus am stating fix the code before we'll buy yet more hardware. I feel that a system should be sized for 90% of the uptime, instead of sizing a system for 10% of the uptime. Do you know of any documentation that may support my case?

I have upgraded our RX6600 HPUX and 11R2 showing an increase of 4%+/- on the processors.
- Rob Hussey
Rita C Workman
Honored Contributor

Re: Searcing for Processor "best practices"

If you're saying that you are only using 21% of your CPU? Well then I'd say you have plenty of resources left to use.

Not everything requires a written document. Best practice is sometimes what's best for your shop. Looks to me like your place has plenty of resources. You're running the box, just monitor your boxes and trust yourself.

Kindest regards,
Rita
Rita C Workman
Honored Contributor
Solution

Re: Searcing for Processor "best practices"

On your last comment...sizing for 10% of time.

Well, guess that one comes down to - which is cheaper, spending time for some programmers who didn't write it right the first time to find their garbage and fix it -or- buy some hardware just to address that 10% of the time peak load.

I call that a management decision.

Rgrds,
Rita

Re: Searcing for Processor "best practices"

If you are moving to 11.31 and 11gR2 on your rx7640, and the nPar it is in is made up of more than one cell board, you should read this whitepaper... enabling NUMA support could gain you a fair bit of performance:

http://h20195.www2.hp.com/V2/GetPDF.aspx/4AA2-4194ENW.pdf

HTH

Duncan

Accept or Kudo

Re: Searcing for Processor "best practices"

Oh and just to answer your original question about nominal levels of CPU utilization, the answer is of course "it depends". Generally as CPU utilization gets above around 50%, you can start to see response times start to increase, although the effect may be insignificant until you approach somewhere arouind 80% (generally the more CPUs you have the higher the utilization number before latency really starts to bite).

The math behind this is quite complex (for a simpleton like me at least), but if it interests you (it doesn't me to be honest) a google seach on:

cpu utilization queueing theory

will turn up some interesting material to peruse.

HTH

Duncan

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Jose Mosquera
Honored Contributor

Re: Searcing for Processor "best practices"

Kenan Erdey
Honored Contributor

Re: Searcing for Processor "best practices"

Hi,

just to add something.

avarege is not really important. you should look at what you need in production times. for example, if you run java program 2 or 3 times in a month, and cpu load gets high and process does not completed in period you expect, you need more cpu resource. or you run a service that servers custemers between 08:00-18:00, you should avarege between these times.

cpu load metric should be taken into. if it's below or about 1, it's ok. there is a correlation betwee them but as mentioned it's mathematical and i couldn't steen understand. i had started a thread about this:

http://h30499.www3.hp.com/t5/General/cpu-load-and-utilization-correlation/m-p/4695729#M146668


generally there is a blief that over %60 utulization cpu load increases etc. but it changes.

after all if your resources are still high, and you want to do something, you can think about partitioning technologies.

Computers have lots of memory but no imagination
Rob Hussey
Advisor

Re: Searcing for Processor "best practices"

I now have a better feeling and some documentation to assist management to pursue resolving the root cause, and not buying processor to overpower the problem by throwing money at it.

Duncan - Some of the documents provided by your suggestion will be good to present to management.

Kenan - The standard range of utility on a monthly basis is 10% to 48%, not using the month with a week of heavy load.

Rita - Your last thought is where I have been going.

Jose - Thank you for the direction.

Thank you all for your help!!!

Rob
- Rob Hussey