Re: Cobol: Maximum number of FD Statements
- From: dennis.roach@xxxxxxxx (Roach, Dennis , N-GHG)
- Date: 3 Mar 2009 06:24:21 -0800
We let them have at it, but protect the system.
They can request what they want. IEFUSI will protect a preset amount of
storage for system use (LSQA, etc.) and also protect the user against a
"give me all" getmain.
If they abuse the issue, we will start seeing paging or aux storage
shortages. Automation detects this with messages and uses PUAUXMON to
determine the large users and kills them. This will, and has, hit
production as well as test. If it is ever a valid usage, then we will
have to allow for it without killing the system. All occurrences so far
have been bugs, even in vendor code.
Dennis Roach
GHG Corporation
Lockheed Martin Mission Services
Flight Design and Operations Contract
Address:
2100 Space Park Drive
LM-15-4BH
Houston, Texas 77058
Mail:
P.O. Box 58487
Mail Code H4C
Houston, Texas 77258
Phone:
Voice: (281)336-5027
Cell: (713)591-1059
Fax: (281)336-5410
E-Mail: Dennis.Roach@xxxxxxxx
All opinions expressed by me are mine and may not agree with my employer
or any person, company, or thing, living or dead, on or near this or any
other planet, moon, asteroid, or other spatial object, natural or
manufactured, since the beginning of time.
-----Original Message-----just
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@xxxxxxxxxxx] On
Behalf Of Mark Zelden
On Mon, 2 Mar 2009 22:04:35 +0000, Ted MacNEIL <eamacneil@xxxxxxxx>
IEFUSIIt wouldn't tell you much at my shop.
Users are "penalized" for coding REGION=0M and dropped down to the
default of 256M.
OTOH, one can get a larger region size by actually coding it here.
About 5 years ago I updated the exit to "stop playing games" and
givepreferred
any requests for more than 1024M the entire private area above theline.
rather
I tend towards the 'slap your fingers' approach to region requests,
than exits.
Restricting region, when it may be needed, has never been my
choice.system
RememberN there is a big difference between the virtual regionrequested
and the real storage to back it up
-
So you would rather crash a system, than slap hands or rely on a
exit for protection? I'd say you are in the extreme minority ofsystem
programmers that would take that position.is
I admit that worrying about 31-bit region size on almost all my
systems
(and REGION=0M) is obsolete / history at this point, but I have a few
very small monoplex LPARs with less than 2G of real storage and
unconditional GETMAINs could still be a problem.
What about 64-bit memlimit? Do you think limiting that with an exit
also a bad approach? Same thing... just rewind 10 years.
Mark
--
Mark Zelden
Sr. Software and Systems Architect - z/OS Team Lead
Zurich North America / Farmers Insurance Group - ZFUS G-ITO
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