RE: Problem with Long Checkpoints

--- Murray Wood <murray@quanta.co.nz> wrote: > > I observed the following ... > > The checkpoint interval is 3000 seconds but checkpoints occur at less > than > 50 minutes. What is causing the quick checkpoint? I suspect that > the > physical log may be too small for that instance. > > Despite the checkpoint duration, you do not have many chekcpoint > waits. > > With 20 AIOVPS you are presumably not running KAIO. How many chunks > do you > have? (2 AIOVPS per chunk). > Can you change to KAIO? You're right. We can't run KAIO on our HP-UX 10.20/IDS 7.24.UC5 environment. We are help up from upgrading to 7.3 by the application vendor certifying their product on 7.3. We have 10 chunks, but they all reside on 4 physical disks (2 - 2.1 gb mirrored pairs). > > > At the time of the checkpoint, what is needed to do? > Do some instances have *longer* transactions than other instances? > Are all instances similar in requirements and performance? > Is there an IO problem on some instances at checkpoint time? > Are some machine(s) more heavily loaded than others, and does that > correspond to the instances with longer duration checkpionts? > The application is exactly the same on all instances. Some instances may have a higher volume of transactions, but this particular instance with the long checkpoints is one of the lower volume operations. I have 2 boxes with 3 instances each that perform better than this box that only has 2 instances, one in production, one soon to be. This is puzzling to me. If the tuning suggestions improve this box, they will be applied to all other instances as well, because the onconfigs are identical(excluding things that must be unique, ie. SERVERNUM) on every instance. > What is the effect of increasing NUMAIOVPS ? > What is the effect of increasing LRUs and CLEANERS ? I'll try these suggestions. This is a 24x7 system, so it may be the weekend before I'll get a change to change them. > > HTH > Murray Wood Thanks for the input!!.....Jeff _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com