Re: Questions on INFORMIX 7.13 and CPU VPs

In article <638pt8$2h7@cssun.mathcs.emory.edu>, sujata_soman_at_omm- la2-infotech-001@internet.omm.com writes > > Hi everybody, > Some more questions for everybody. Feel free to answer > . I have a lot of questions on CPU VPs and performance. Here goes: > > some background info: > OS -AIX 4.1 > Informix : 7.13 UC1 > Number of CPUs - 8 > > > 1. Is it true that we can configure only one NETTYPE connection on the > CPU VP ? Currently, both my NETTYPE connections ( SOC and SHM ) are > configured on CPU VPs. If my assumption is true, does INFORMIX > automatically force the second NETTYPE connection to a NET vp ? > I though so and I tend to put the SHM one on the CPU VP as it has less overhead. I would run TCP/IP stuff on a separate NET VP. > 2. I expect about 400 connections through shared memory and 200 > through SOC. Which of the connections should be configured through CPU > VP ? The ODS Performance guide suggests that if # of connections > > 350, then performance would be improved by assigning a NET VP to it. > Any comments ?? > Talking over the network will require run code that talks to the network drivers and personally I'd rather have that access by one process since a) it is not very PU intensive - mainly waiting for the network b) Having the network code running only on one process provides better "locality of reference" ie. better caching. > > 3. An onstat -g sch shows some of my CPU VPs to be a whole lot more > busy than the others. What determines the usage of a CPU VP ? > This is handled internally by online depending upon how many threads are ready to run at a given time. Don't worry about it, there is nothing you can do/ > > 4. Okay, a question not related to CPU VPs. At the end of an onstat -u > output, we see the following line: > # active, # total, # concurrent. > If we actually count the total # of sessions, it matches with the > "# active". Where does the "#total " and "# concurrent" come from ? # ative = current number of sessions. # total = maximum number of seesions allow (either from NETTYPE or USERTHREADS in early 7.1x versions which still had USERTHREADS). # concurrent is the maximum #active since online was started. > > 5. Okay, I am going to cheat again and ask another non-CPU VP question > onstat -g ioq , shows me a Queue named "kio". I do not think that> this is related to the KAIO. Matter of fact, the total number of these > queues seems to equal the NUMCPUVPS. Comments ?? > This is related to KAIO. KAIO is handled by kaio threads which run on the CPUVPS. There is one kaio thread per cpu vp. The kaio queue is the KAIO queue. > > > No more for now. > > Thanks in advance. > > Sujata > > -- David Williams