RE: Online performance and Multiprocessors.

Hi Richard! Performance & Tuning involve many things, not only memory and = processors, and I personally think that this is a serious subject, nobody in this = list will tell you what is the source of your problem (Unless monitoring your = system), and believe me the source can be from memory, application, = processor speed, and first you must determine the cause of the problem, = and I really recommend you an INFORMIX CLASS, you may take Server System = Administration & Performance Tuning, anyway here are some answers to = your questions. onstag -g glo shows information about the CPU usage of vps currently = running OnLine System. You can determine how much processor the CPU VP is using with a simple test. Running onstat - glo, then wait one minute and run=20 onstat -g glo again. Subtract the total CPU time for each CPU VP in the=20latest output from the total CPU time in the earlier output. The result = will be the amount of time the CPU VP used the processor. If the result approaches = 60 seconds, then the CPU VP is very busy and you may benefit from adding another CPU VP (on multiprocessor systems) or running a faster = processor. Anohter way to to this is running onstat -g rea , which will display = information about threads waiting to run in the ready queue, Although the goal is to = reduce the ready queue to 0, at some point, adding more CPU vps will not help=20 performance as the processors may be completely busy. In this case, you may see the ready queue constantly busy, Adding more hardware processors to your system may improve performance. It is important for you to know the database structure you are = administering, is it normalized?, Are the correct indexes built?, maybe the slowness = comes from SCAN READS in an no index column, or you just simple has not=20 implemented PDQ for your reports using aggregates, Sometimes a report orders by a column DESCending and the index is not that way, could be a source of slowness. Affinity Processor works with solaris 2.5.1, anyway, you should consider taking the class, because performance & tuning is a serious subject. I hope this helps, -------------------------------------------------------------------------= ------------------ Mario Estrada / SISTECO, S.A.,Guatemala,C.A. Departamento de Soporte / Phone (502) 3318116 INFORMIX / Fax (502) 3348447 -------------------------------------------------------------------------= ------------------ The opinions expressed here, are not those of my company -------------------------------------------------------------------------= ----------------- Richard Hewitt wrote the following: ---------- De: Richard Hewitt[SMTP:oneten@compuserve.com] Enviado: martes 21 de enero de 1997 5:43 Para: informix-list@rmy.emory.edu Asunto: Online performance and Multiprocessors. Hi, I know next to nothing about administering Online, and my users are complaining about the database being slow sometimes.=20 Could some kind soul outline the simplest method for indicating whether putting an extra processor and/or extra memory would solve the bottleneck? I have tried using=20 onstat -g gloas stated in the manual but the output means nothing to me. The OS is currently using less swap space than it has RAM, so I don't imagine that it needs more memory, and forking out 5 grand for an extra processor is quite a lot if it doesn't make a bit of difference!! I have read about binding online to use an extra CPU exclusively - does anyone know if this is possible with Solaris 2.5, and if so, does it work? Does it improve performance significantly? I expect that the biggest performance gains would arise from correct structuring of the database, indexes etc - I unfortunately don't have any input on that side of things - I am just the lowly sysadmin and it's my fault that it is running slowly! I am running Online 7.1 under Solaris 2.5 on a SS20 with 64Mb RAM and processor. Thanks in advance, Richard Hewitt