[email protected] (Gabe Goldberg) writes: > Indeed. Then a couple people responded. Good timing; I'm writing > article on TPF for Destination z or IBM Systems Magazine (I forget > where it'll be published). IBM TPFers have been very helpful and I'm > contacting TPF users group: http://www.tpfug.org/ . I didn't post here > because .... well, I just didn't, but I should have. Better late than > never: I'm interested in TPF insights, experiences, etc. > > Be brief, this won't be an epic article, though there might be > follow-on pieces. Please copy me directly so replies aren't buried in > the list digest. > > Thanks... > > Rick Troth said on IBM-Main: Lineage of TPF would also be interesting.
Before Jim left for tandem (earlier post about RDBMS, System/R, DB2) ... he was looking for real live DBMS locking statistics for profiling System/R (RDBMS) performance. This included data from ACP 3830 controller RPQ ... logical/symbolic locks implemented in the 3830 controller (much more efficient than device reserve/release) ... minor note IBM wanted to depreciate the ACP RPQ because corporate strategy was to push "string switches" ... which allowed two different controllers to get to the same device (and bypass "locks" in the other controller). old email refs: http://www.garlic.com/~lynn/2008i.html#email800325 The customer statistics in above ... was just before the looming 3081 "crisis" (while ACP/TPF had loosely-coupled cluster support, it didn't have tightly-coupled, SMP support). Note above mentions two controlers (with string-switch) ... but it is same system having access to both controllers for redundancy. As aside, US HONE datacenters were consolidated in Silicon Valley in the mid-70s (HONE was the world-wide, online sales&marketing support system). By the late 70s, the US HONE system had the largest "single-system image" loosely-coupled configuration in the world (with load-balancing and recovery across all systems in the complex) ... and required string-switch with pairs of controllers each with multiple channel connections in order for all the SMP (multiprocessor) systems in the complex to fully access the large DASD farm. Rather than locking (device reserve/release) for the necessary operations, it used a special CCW sequence (when needed) that emulated the compare-and-swap instruction semantics. past posts mentioning charlie invented compare-and-swap while doing fine-grain multiprocessing locking on CP67 at the science center ... past posts http://www.garlic.com/~lynn/subtopic.html#smp and http://www.garlic.com/~lynn/subtopic.html#545tech trivia: when facebook moved to silicon valley it was to a new bldg. next door to the old HONE datacenter. misc. past posts mentioning HONE http://www.garlic.com/~lynn/subtopic.html#hone Of course the (HONE cluster) "single system image" support wasn't made available to customers until 30yrs later (late last decade). -- 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: INFO IBM-MAIN
