Re: Question about CPU utilization

Jï¿œrg Rï¿œschenschmidt wrote: > Hi, > > I have question about CPU utilization. My system is a HP UX 11.11 with > IDS 10.00.FC5. I heard once IDS is well configured if you have > usercpu/syscpu relation of >= 4 in onstat -p. > > Today I checked my instance and I found a relation of 2 only. My > conclusion : There is something to tune ! Following Andreas's assumption that your problem is that you are seeing high CPU usage with few connections. However, I am confused. You state that you tried different NETTYPE settings but not that you changed the sqlhosts entries or INFORMIXSERVER value to correspond. Did you? That asside, I have always held that TCP and STR PIPE connections should be handled by NET VPs in the NETTYPE settings and that shared memory connections are best served by CPU VPs in NETTYPE for the very symptom you are seeing. If you set TCP listeners/poll threads in CPU VPs you will experience vastly increased system call overhead from the CPU VPs and poor response time to user requests when the server is busy (in your case that doesn't seem to be a problem, though). Similarly if you put the SHM listener/poll threads into NET VPs the system call overhead will go through the roof!. Also, unless you set up shm connections just for the occassional maintenance task, I would set the shm nettype to the same number of CPU VP poll threads as you have CPU VPs configured. Normally you need relatively few NET VPs though (but I like at least 2 for improved responsiveness, makes the server seem more crisp to users) as a single NET VP can easily handle over 500 connections. So (assuming 2 CPU VPs configured since you didn't specify): NETTYPE ipcshm,2,100,CPU NETTYPE soctcp,2,100,NET Art S. Kagel > I checked onstat -g glo and I found high syscpu in 'soc' class, which > cause the bad total numbers. > > Currently NETTYPE soctcp,1,100,NET is used. I tried to move it to CPU, > because one single thread is used only. This will shift the high syscpu > to 'cpu' but no improvment in total. > > Furter I tried NETTYPE ipcstr,1,100,NET instead of soctcp. In this case > 'str' class shows the high syscpu. > > Finally I tried to use FASTPOLL feature, but I could not recognize any > difference. > > It looks like the communication protocol keeps the HP system busy. > > Is there something i missed ? Any ideas ? > > Regards ... > > Joerg Rueschenschmidt