This is a followup to my series of questions about BLSR/SMB/LSR statistics
back in May of this year. My capacity and performance gurus queried IBM at
my request and came back to me to say that there ARE no VSAM LSR statistics
sent to SMF.
Can anyone here confirm or deny this statement? My C&P gurus have said that
they asked on IBMLink (to which I do not have access) and were told that no
such statistics were sent to SMF after CLOSE of a VSAM LSR ACB.
It just does not seem right or sensible to me that VSAM LSR code would keep
statistics (see below) while the file is open but fail to write them out to
SMF on CLOSE (whether by EOT/EOJ or user CLOSE).
Especially for HLL code (COBOL, PL/1, etc.) that invokes BLSR or SMB via
JCL, and not directly via programmer coding of a VSAM LSR ACB, it would be
difficult to set up an assembler SHOWCB before CLOSE to extract such
statistics from the ACB independently. Just locating the ACB in the first
place would be non-trivial and possibly HLL release-dependent.
TIA for your help in confirming or denying what I have been told. If VSAM
LSR stats are in fact sent to SMF, I'd also appreciate a pointer to which
SMF record to tell my C&P gurus to look at.
Peter
P.S. -- I have been asked WHY do I want to see these statistics? Easy -- to
help tune the optimal size of the pool for each file with finer-grained data
than raw EXCP/SIO counts and total memory usage for the job. Performance of
my application code is my responsibility, and I take it seriously. I want
every tool I can find to help me with that job.
Snippet from 05/10/2007 message to the list:
It appears that VSAM LSR keeps certain statistics for each buffer pool from
the time it is created to the time it is deleted. You can get the current
values by using SHOWCB with an ACB that is already OPEN using LSR and that
buffer pool. These are the available stats, according to "z/OS V1R6.0
DFSMS: Using Data Sets":
Field Description
BFRFND The number of requests for retrieval that could be
satisfied without an I/O operation (the data was found in
a buffer).
BUFRDS The number of reads to bring data into a buffer.
NUIW The number of nonuser-initiated writes (that VSAM was
forced to do because no buffers were available for reading
the contents of a control interval).
STRMAX The maximum number of placeholders currently active for
the resource pool (for all the buffer pools in it).
UIW The number of user-initiated writes (PUTs not deferred or
WRTBFRs, see "Deferring Write Requests" in topic 2.8.2.1).
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
