Hi They were custom applications. PL/SQL, Forms, Reports. We migrated from Sun Solaris to HP-UX. The HP guy took Sun CPU clock speed and turned that in HP-UX Itanium CPU clock speed. Mathematics basically. For example if Itanium CPU is twice as fast as a Sparc CPU, if the Sparc has a clock speed of 400 Mhz and Itanium has 800 Mhz then 8 Sparc CPU is equivalent to 400 * 8 = 3200 3200 / 2 / 8 = 2 i.e 2 Itanium 800MHz CPU were equivalent to 8 400MHz Sparc CPU. I was amused but hey he was the expert not me! :-) I did tune a bit the application. I was not allowed to tune too much because my job was migration and not tuning. Basically a Data Mart was killing the server. There were 2 instances running in the server. Cheers -- LSC On 2/23/06, Jurijs Velikanovs <j.velikanovs@xxxxxxxxx> wrote: > > > In my last project for example, a HP guy estimated 12 CPUs for a server > > however in the practice we almost doubled otherwise the server would be > CPU > > bounded. > What kind of application we are token about? Is it custom made? > Have you tried to tune performance of the application before doubling > resources? > Was is RISC or Intel based server? > Was it TOP SQL(-s) which consumed 90% of CPU? > > Jurijs > > On 2/23/06, LiShan Cheng <exriscer@xxxxxxxxx> wrote: > > Hi > > > > Thanks for the reply. > > > > I am quite lost in this area basically becase I am quite reluctant about > > capacity planning since I have seen quite a few and I have seen cero > > success. Many times I would really like to ask the guy who did the plan > how > > he did it without knowing so many factors. > > > > In my last project for example, a HP guy estimated 12 CPUs for a server > > however in the practice we almost doubled otherwise the server would be > CPU > > bounded. > > > > I understand it is necessary but... whose job should it be? DBA? > Hardware > > Vendor? Software Maker? System Admin? Mix of all is probably the answer > but > > then what information is needed by a DBA to perform such job? > > > > Shall I tkprof 10 sessions get the cpu time and multiply by the real > number > > of users I will have? :-) > > > > Cheers > > > > -- > > LSC > > > > > > > > > > On 2/23/06, Jurijs Velikanovs <j.velikanovs@xxxxxxxxx> wrote: > > > I'm interested in that question as well. I believe almost all DBA-s > > > had, have, will have to answer it. > > > The most difficult for me was CPU power, I/O throughput and Memory > > > planning for home made (custom development) applications > > > . > > > By my experience you can spend tremendous amount of time (not just > > > yours time) creating capacity plan for a particular system during an > > > application development time. Work with analysts, designers, > > > developers documenting detailed calculations and all assumptions. But > > > end of the day you will get, a +/- 50% accurate result ;). > > > If at the end the applications will not perform well enough the > > > Developers will blame HW and will some think like "You need double HW > > > resources to get XX sec response time". DBA-s and Admins would say "We > > > already have some thing like top HW". It is always difficult to say if > > > developers have done their work well without knowing the applications > > > business. > > > . > > > At the moment I think that most effective way to plan that type of > > > capacity is make assumptions based on you or others project members' > > > previous experience. > > > - If in the past you have worked with kind of systems you currently > > > developing you know already the most important parts of application > > > you have to pay attentions. This is there you have to concentrate your > > > attention. In most cases it is something like 2% of overall > > > application code. Describe, prototype, play with that bit and of the > > > day you will get -/+ 10% accurate planning. > > > - If in the past you have worked with much bigger systems, with huge > > > amount of data processing you can think like. This system is 5 times > > > smaller the system I have worked with. Presumably this system will run > > > successfully on 2-3 times smaller HW and we will spend 2 times less > > > time to tune it. > > > - If you have chance to get information about system like you are > > > going to implement (like OEBS, SAP, or other pre developed > > > application, or the same functional application, or old system you > > > going to replace), you can base your assumption on that information. > > > . > > > Later on then Developers will say you haven't enough HW capacity, you > > > would be able to base you conclusion on a comparison of the developed > > > application and other systems. > > > . > > > I don't think this approach is ideal, but at the moment I haven't > found > > better. > > > I would be glad to hear others opinion. > > > > > > Thank you in advance, > > > Jurijs > > > > > > > > > On 2/23/06, LiShan Cheng < exriscer@xxxxxxxxx> wrote: > > > > Hi > > > > > > > > I was wondering if anyone know any source about effective Oracle > RDBMS > > > > Capacity Planning. I mean effective because in the past I have seen > many > > so > > > > called "Capacity Plan" which failed miserably in the practice. I am > not > > sure > > > > how can a DBA perform Capacity Planning without knowing much about > the > > > > application? > > > > > > > > Cheers > > > > > > > > > > > > LSC > > > > > > > > > > > > > > > > > -- > > > Jurijs > > > +44 7738 013090 (GMT) > > > ============================================ > > > http://otn.oracle.com/ocm/jvelikanovs.html > > > > > > > > > > -- > Jurijs > +44 7738 013090 (GMT) > ============================================ > http://otn.oracle.com/ocm/jvelikanovs.html >