[email protected] (Tom Harper) writes: > I'm not so sure. Many CICS shops have pointed out to me that they are > forced to run hundreds of CICS regions for the simple fact that 2G is > not enough address space to contain all of their programs. This > requires them to spend an inordinate amount of time managing regions > for the sole reason of address space exhaustion. > > There is no question that there are other consumers of address space > in the CICS regions, but many of these are buffers which have to be > duplicated in every region, and in any case are not the limiting > factor.
I always thot that the hundreds of CICS regions sprouted up from when CICS lacked multiprocessor support ... the only way to get execution on more than one processor was to go to multiple regions. Then there was problem of inter-application corruption ... lots of regions was method of partitioning/fencing off problems ... somewhat akin to having test/sandbox LPARs. CICS multiprocessor support is relative recent in mainframe timeframe ... and it would take major motivation for large installation to make any significant change in production environment. recent post on the subject: http://www.garlic.com/~lynn/2010g.html#80 with these references (that have gone 404 but live on at the wayback machine): The Evolution of CICS: CICS and Multi-region Operation (1980) http://web.archive.org/web/20040705000349/http://www.yelavich.com/history/ev198001.htm The Evolution of CICS: CICS and Multiprocessor Exploitation (2004) http://web.archive.org/web/20041023110006/http://www.yelavich.com/history/ev200402.htm ... disclaimer: I was undergraduate at univ that had gotten ONR grant to do univ. library online catalog ... used part of the money to purchase 2321 datacell ... and also selected to be betatest site for cics product ... and I got tasked to support/debug CICS. I found/fixes some CICS bugs related to univ. library selecting different set of BDAM features (that had been in use at original CICS site). -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
