OK, let me summarize the answers so far for the archives: 1. (From several private responses) IBM has or used to have a performance measurement tool called VLBPAA, possibly available from MKTTOOLS (see <http://www.redbooks.ibm.com/redbooks/pdfs/sg242557.pdf>) that would measure hit ratios and model (based on GTF data) what impact increasing #buffers would have on hit ratios.
2. Why bother measuring? What's the real cost of a few thousand buffers? Can that be measured? It's only virtual memory. 3. Forget about BLSR, use SMB and a large buffer space instead. Oh, and that also means use only SMS/VSAM Extended (if you're allowed to). I am surprised there are/were no basic statistics kept on such an obviously performance-related tool as BLSR. But then, I guess if SMB replaces BLSR then no one would bother going back to retrofit measurement tools into it, either, regardless of whether it was hard or easy to do so. If it had been me, basic stats would have been built-in from day 1 for things like actual count of buffers ever used for data and index, total BLSR CPU time used, and maybe even hit counts and total searches. None of these would have been hard to do and would have provided useful information to users. And a report option for WTO of EOJ stats would have been nice-to-have as well. And none of it would have required GTF. Peter -----Original Message----- From: Farley, Peter x23353 [mailto:Peter(dot)Farley(at)BROADRIDGE(dot)COM] Sent: Monday, May 07, 2007 1:48 PM To: [email protected] Subject: How to measure actual usage of BLSR buffers? I did search the archives for this one, but I did not find any references. Is there some way to measure how many BLSR buffers (data and index) were actually used after a job has completed? For instance, if BUFND=2700,BUFNI=180 was specified in a SUBSYS=(BLSR,...) DD statement, how could I discover how many of the 2700 data buffers actually were used for reading or writing some CI in a VSAM KSDS? And if such a method exists, can ordinary application programmers (e.g., those with no authority to use DCOLLECT) use the method? Obviously, this is a tuning effort at the application level. I know that BLSR dramatically reduces my EXCP count in this application while slightly raising the CPU time, but I have a need to measure how much of the allocated memory is actually being used by the BLSR specification, and how much is excess unused space. TIA for any info/url/RTFM you can provide. This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- 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
