Re: how much cpu does Informix use

Floyd Wellershaus wrote: > Hey Art, Thanks for the reply. Please see my responses intermixed > with yours. > > ----- Original Message ----- > Subject: Re: how much cpu does Informix use > Date: Thu, March 27, 2008 9:52 > From: "Art S. Kagel (Oninit)" > Floyd Wellershaus wrote: > > > IDS10 on AIX 5.3. > > > Sorry if this has been asked before, but I still don't have a > > > satisfactory answer. > > > We are trying to determine exactly how much percentage of our system > > > cpu, that Informix is using through time. > > > This is proving to be a difficult task, because sar doesn't provide > > > process names or id's so that I can correlate a percentage to > 'oninit'. > > > ps command doesn't provide percentage. > > > > Sounds like what you want is 'top'. You should be able to get an AIX > > specific executable from IBM and IB that IBM also has an enhanced > > version of top for AIX called 'topas' or download the generic UNIX top > > source from sourceforge or www.unixtop.org <http://www.unixtop.org>;. > > We have topas, but I am unable to make it provide the information for > all oninit processes. It seems to only care about the top 10 or so > processes. > > > > > > > > I am thinking that at least I can use onstat -g glo, add up all of > the > > > total time for cpu vps ( because I think those are the metrics of > what > > > oninit does on the physical cpus ). > > > > > > First question: Am I correct that only the cpuvps are directly > tied to > > > the physical cpus? Or do I need to be counting all of the vps ? > > > > That depends. If you are using a version before 9.40 (don't remember > > your specs Floyd - sorry) that's certainly true, the AFF* parameters > > only affect CPU VPs. In 9.40 and later if you are using VPCLASS to > > specify VP settings (rather than the vp class specific parameters like > > NUMAIOVPS) you can set affinity for any VP class that can be configured > > using the VPCLASS parameter. > > > > Not sure I get what you're saying. So we don't define VPCLASS, we just > have NUMPAOVPS, NUMCPUVPS etc.... So does that mean we do count the > aiovp stats when adding up the "physical" cpu time ? What about Soc, > lio etc... , or just CPUVP'S ? It just means that the AIOVPS are not affined, they will float across all CPUs unless you have done something external to IDS to restrict their migration. > > > > > > Second question. The numbers provided for each cpu is what ? > Seconds ? > > > > Yes. > > > > > So, assuming that oninit has been up the entire time that the lpar > has > > > been up, if I divide the total time from onstat -g glo by the number > > > of seconds since the lpar has been up, will that tell me the > > > percentage of cpu that oninit uses ? > > > > Yes. That would be percent of available CPU if you add up all of the > > CPU times for all VPs (or for given classes of VPs) and divide that by > > the number of CPU Cores available to the instance time seconds since > the > > IDS instance was started that would give the percent of total CPU time > > used. If you only multiply by the number of CPUs to which the VPs were > > affined that would give the percentage of available assigned CPU > time used. > > > Again, I need more clarity on this. We aren't using any processor > affinity. > Say I have 2 cpuvps that are up for one day ( 86400 seconds ). > Say the total time for both of them comes to 43200 seconds. > If I have 2 physical cpus on the machine, does that mean informix used > 50% of available cpu or 25% ? It means that the 2 CPU VPs together used approximately 25% of the available CPU time equivalent to 50% of a single CPU. Art S. Kagel Oninit > > Thanks !! > > > Thanks for any advice on this. > > > > > > Floyd > > Art S. Kagel > > Oninit > > > > > > > > > ------------------------------------------------------------------------ > > > > > > _______________________________________________ > > > Informix-list mailing list > > > Informix-list@iiug.org > > > http://www.iiug.org/mailman/listinfo/informix-list > > > > > > > > >