NETTYPES and FASTPOLL = 1

IDS 11.5.FC5 AIX 5.3 One (oldest) server: 10 CPU 1.6Ghz Power 5 Single Thread/CPU System One (newest) server: 16 CPU 3.8ghz Power 6 Multi-Core/CPU System (so, 32 CPU thread allocation). NETTYPE ipcshm,1,350,CPU # Configure poll thread(s) for nettype NETTYPE soctcp,9,350,NET # Configure poll thread(s) for nettype FASTPOLL 1 onstat –u | tail: 1774 active, 2304 total, 2231 maximum concurrent At least, initially, they will have approximately the same number of users when they complete their migration to the new server. I have recommended, for the oldest server, they reduce the number of NET threads from 9 to 7. That would be capable, using what I know, of easily handling 2450+ connections and, according to the Performance Guide, actually much, much more. [starting on page 3-12] To which management has replied: Interesting, I had read the opposite and had considered raising the number of polling threads. I had recently read that the limitation of one thread per CPU core was originally recommended based on much slower processors, but today’s processors could easily handle more than one thread, and that reducing the number of connections per polling thread would yield better performance. Could you do some more inquiries on this issue? So ... I would like to hear from others as to how to configure for the oldest server ... as well as the newest, as I have not worked on any dual core AIX servers before. Thanks in advance and have a great weekend. Clifton _________________________________________________________________ Windows 7: Simplify your PC. Learn more. http://www.microsoft.com/Windows/windows-7/default.aspx?ocid=PID24727::T:WLMTAGL :ON:WL:en-US:WWL_WIN_evergreen1:102009

IBM recommends keeping the number of connections per poll thread under 350. Although a single poll thread or NET VP can handle over 1000 connections, apparently responsiveness is less than ideal with more than 350 connections per NET VP. Personally, I like to configure for 200-250 per NET VP so that unusual peak loads don't pull the total much over 350. However, there is no good reason to configure way down to say 50 or 100 connections per NET VP. As to the number of VPs on a system, the older limitation of a single VP per processor core and the newer recommendations, that your management has read about, refer to the CPU VPs specifically. The NET VPs rarely use sufficient CPU resources that one need take them into consideration unless one require a boat load of them. The rule of thumb that I developed several years ago was one CPU VP per core per 450-500MHZ of processor power (use 750MHZ for Intel processors and ignore hyper threads - they are NOT cores). This is probably what your management has been reading. Over the years this has held up very well, but again, doesn't address the NET VPs at all. Honestly, I would not reduce the number of NET VPS below 8 (set with 350 connections each initially) and might agree with manaagement and recommend increasing it to 10 ( set with 250 connections each initially) to keep within my comfort zone of 200-250 connections per NET VP. If your shared memory connection is used for more than just maintenance I would configure the same number of shared memory listeners as CPU VPs and configure the number of connections to be close to the actual peak shared memory connection load (the 350 looks suspiciously like it was set to agree with the TCP setting for convenience). If shared memory is only used for maintenance, I like to configure two threads just in case the first CPU VP (which runs the first listener thread) is busy or hung and I have to get into the server NOW for some reason (yes that's happened to me). Art Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Fri, Oct 23, 2009 at 1:50 PM, Clifton Bean <clifton_bean@hotmail.com>wrote: > IDS 11.5.FC5 AIX 5.3 > > One (oldest) server: 10 CPU 1.6Ghz Power 5 Single Thread/CPU System > > One (newest) server: 16 CPU 3.8ghz Power 6 Multi-Core/CPU System (so, 32 > CPU > thread allocation). > > NETTYPE ipcshm,1,350,CPU # Configure poll thread(s) for nettype > NETTYPE soctcp,9,350,NET # Configure poll thread(s) for nettype > FASTPOLL 1> > onstat –u | tail: 1774 active, 2304 total, 2231 maximum concurrent > > At least, initially, they will have approximately the same number of users > when they complete their migration to the new server. > > I have recommended, for the oldest server, they reduce the number of NET > threads from 9 to 7. That would be capable, using what I know, of easily > handling 2450+ connections and, according to the Performance Guide, > actually > much, much more. [starting on page 3-12] > > To which management has replied: > Interesting, I had read the opposite and had considered raising the number > of > polling threads. I had recently read that the limitation of one thread per > CPU > core was originally recommended based on much slower processors, but > today’s > processors could easily handle more than one thread, and that reducing the > number of connections per polling thread would yield better performance. > Could > you do some more inquiries on this issue? > > So ... I would like to hear from others as to how to configure for the > oldest > server ... as well as the newest, as I have not worked on any dual core AIX > servers before. > > Thanks in advance and have a great weekend. > Clifton > > _________________________________________________________________ > Windows 7: Simplify your PC. Learn more. > > > http://www.microsoft.com/Windows/windows-7/default.aspx?ocid=PID24727::T:WLMTAGL :ON:WL:en-US:WWL_WIN_evergreen1:102009 > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --001517478d80b2f5d604769e3c79