Thanks Dr. Merrill for your illustrative example but I do have a question about it. Since L8 TCBs are used to execute DB2 code as well, what part of 10,298 seconds is for DB2 ? Since DB2 related code never executed on QR TCB anyway, that portion of CPU usage is moot for this discussion. The real question is how much of this CPU now runs on L8 TCB which used to run on QR TCB due to the aggressive OTE exploitation ? Regards Mohammad
On Wed, 12 Aug 2009 15:18:23 -0500, Barry Merrill <ba...@mxg.com> wrote: >In the old days, a CICS subsystem's capacity was limited by >the amount of CPU TCB time needed for that single QR TCB. > >Based on my analysis when OTE was brand new, of the CPU time >consumed by each of these new CICS TCBs, I planned this post >to argue that going to OTE didn't help much, because most of >the CICS CPU time was still being spent under the QR TCB. > >I could NOT have been more wrong! > >Analyzing new CICS/TS 4.1 Open Beta data from a VERY >aggressive OTE exploiter site shows (from their >SMF 110, subtype 2 Dispatcher Statistics segments, >MXG CICDS and CICINTRV datasets): > >Total TCB CPU in Dispatcher Records = 13,080 seconds >Total TCB CPU in QR TCB = 2,776 seconds >Total TCB CPU in L8 TCB = 10,298 seconds >Total TCB CPU in all other TCBs = 6 seconds > >Aha, you say, OTE still doesn't help; the CPU time just moved >from the QR TCB to the L8 TCB, so the capacity limit just moved >from one TCB to the other, right? > >Wrong again. > >While the QR TCB can attach only a single TCB, these new TCBs >can attach multiple TCBs; in fact, the SMF data shows that >the L8 TCB attached a maximum of 22 TCBs, each of which >is a separate dispatchable unit. > >So, it REALLY does look like that these multiple OTE TCBs >do eliminate the old "one-TCB" CICS capacity limitations, >and does indeed spread your CICS time across MANY TCBs. > >(Total SRB time in the Dispatcher Records was only 65 seconds.) > >Barry Merrill > >Herbert W. Barry Merrill, PhD >President-Programmer >Merrill Consultants >MXG Software >10717 Cromwell Drive >Dallas, TX 75229 > > ba...@mxg.com > http://www.mxg.com > admin questions: ad...@mxg.com > technical questions: supp...@mxg.com > tel: 214 351 1966 > fax: 214 350 3694 > > > > >---------------------------------------------------------------------- >For IBM-MAIN subscribe / signoff / archive access instructions, >send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO >Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
