Thanks for the history and a definitive word on BLSR. From your (and others') remarks, it seems obvious that BLSR has been supereceded by SMB. So why not just implement SMB?
Doesn't SMB only work if the clusters whose buffers you want to manage are defined as extended format? In contrast, BLSR does not require extended format, correct? Extended format datasets are the exception where I am employed, not the rule. Recreating the DASD farm in extended format would be a gargantuan task, requiring the buy-in of far-flung managers with limited technical acumen who'd see such efforts as a lot of work for very little benefit. At this point, implementing BLSR until SMB can be a reality might provide some immediate relief. -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Jim Mulder Sent: Thursday, May 19, 2022 12:55 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: IBM BLSR subsystem BLSR was initially developed by Washinton System Center as an assembler language sample program to go along with a book they were writing about using the Subsystem Interface. At the time, IBM was desperately looking for "ESA Exclusives" in order to sell 3090 machines vs the PCM manufacturers, who machines had not yet implemented ESA. This sample program happened to use one BAKR/PR, which meant that it did require ESA. So MVS management wanted to instead ship the program an OCO part of the MVS BCP, and I was commanded to review the code to see what that would entail. I raised several objections concerning the maintainability of the code, the lack of serviceability (no ESTAEs, no dumping, no control block eyecatchers, we didn't want new assembler code), no message IDs, lack of messages and message control, an integrity exposure, etc, etc. Also, VSAM functionality was not really in the BCP's bailiwick, and we would end up having to support this code for decades. So I recommended that we should not do this. But, since selling machines trumps everything, I lost that argument, and was instead assigned to remediate all of my objections to the sample code. I recoded the whole thing in PL/AS and fixed all of the issues, and wrote lots of testcases, and it got shipped as a PTF on top of MVS/ESA SP3.1.3. MVS Project Management did contribute the "Batch LSR" name. Decades later, we continue to support it and probably always will, but at least the right solution eventually got implemented by SMB in DFSMS. And now you know... the rest of the story. James Harvey Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY ________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Dave Barry <000000a5644c6d08-dmarc-requ...@listserv.ua.edu> Sent: Wednesday, May 18, 2022 5:43 PM To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU> Subject: Re: [EXTERNAL] Re: IBM BLSR subsystem >IIRC, Batch LSR was developed at IBM by the BCP team; SMB was later developed >by the DFdfp team. SMB is not BLSR under-the-covers, but it offers the same >advantages. >SMB is the more modern solution. It has worked wonders at my shop. Just mind >your REGION size. If you haven't converted some VSAM files to Extended >Format, this is a good reason to do so. >The VSAM Demystified Redbook is a good resource. Lots on the Web, e.g. >https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.i >bm.com%2Fdocs%2Fen%2Fzos%2F2.5.0%3Ftopic%3Dresource-tuning-system-manag >ed-buffering&data=05%7C01%7Cmichael.watkins%40CPA.TEXAS.GOV%7C2ea34 >0e656744339ec3b08da395c32ba%7C2055feba299d4d0daa5a73b8b42fef08%7C0%7C0% >7C637885365415122967%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIj >oiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=8kne >cZQfc8fCOXxtg2R0PiSnEkiHPgN3ZbJIv8o6Q%2FA%3D&reserved=0 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
