ca.portal.admin

Re: WHAT is DB-MODE???

Discussion created by ca.portal.admin on Feb 20, 2008
Sorry for the empty message.

Actually DB MP mode (or any other mode, except for ANY mode) doesn't single
thread the whole IDMS work, only the tasks which are in the same (DB) MP
mode.
In a unitasking CV the problem does not exist since the CPU is not available
to other tasks waiting (for CPU) until it is finished or until it
requests another service from IDMS and goes into a wait state.
If those modes wouldn't have been single threaded then few different tasks
could collide in doing their assigned MP mode IDMS function.

User programs (and also some IDMS system code) can however execute
concurrently without the danger of integrity compromise to IDMS internal
structures.
The separation to different MP modes (actually not all of them are in use),
like DB and DC etc., is to enable a higher level of concurrency among non
colliding functions of the IDMS system


HTH
Rafi Gefen
IDMS DBA
+972-54-5767234
On Wed, Feb 20, 2008 at 11:55 PM, Petzold, Lutz <PetzoldL@aetna.com> wrote:
This is interesting to me Rafi since we're running multitasking. So,
you're saying that MPmode DB single threads the IDMS database work under
one TCB? Only the MPmode ANY is multithreaded under multiple TCB's?

Lutz Petzold
TDM UDB/IDMS Support
(401) 782 2265 or (860) 636 0291
Pager (860) 366 0865 or Telalert



-----Original Message-----
From: IDMS Public Discussion Forum
[mailTo:IDMS-L@LISTSERV.IUASSN.COM] On Behalf Of Rafi Gefen
Sent: Wednesday, February 20, 2008 4:46 PM
To: IDMS-L@LISTSERV.IUASSN.COM
Subject: Re: WHAT is DB-MODE???

Multitasking option of IDMS is implemented by categorizing
IDMS work into different states/MP Modes:
DB,DC,LOADER,DRIVER,USER and ANY.
All states/modes, except ANY, are single threaded in order to
preserve IDMS system internal structures and state integrity.
IDMS tasks in different MP modes can concurrently execute by
separate OS TCBs under control of the CV.
These TCBs can concurrently run on different CPUs of the machine.
This way, few tasks, but only one of each MP mode (except ANY),
can execute concurrently on separate CPUs.
Multiple tasks having MP mode of ANY (usually user programs)
are allowed to run concurrently with other tasks in any MP mode.

This is how concurrent CPU execution (more than one CPU
concurrently servicing a single IDMS CV Address Space), AKA
Multitasking, is achieved by IDMS.

HTH

Rafi Gefen
IDMS DBA

On Wed, Feb 20, 2008 at 6:48 PM, William M. Allen, Jr. <
archcons@bellsouth.net> wrote:
Hello All:



In this APAR is states ""DB MODE"" what is this?



APAR #: QO94231 DATE: 19 FEB 2008







PROBLEM DESCRIPTION: IDMS GETS A SEQUENCE ERROR IN THE JOURNAL.





------------------------------------------------------------

WITH A SYSTEM RUNNING IN DB MODE, IDMS MAY CAUSE A



SEQUENCE ERROR WITHIN THE JOURNAL. THIS WILL SHOW UP



IN THE ARCHIVE JOURNAL AS A SEQUENCE ERROR. AUTOMATIC



RECOVERY WILL FAIL. IF THE SYSTEM CRASHES, WARMSTART



WILL ALSO FAIL. BECAUSE THE JOURNALS CANNOT BE OFFLOADED



ROLLBACK OR ROLLFORWARD CANNOT BE RUN.







NOTE: THE LOWEST MAINTENANCE LEVEL TO WHICH THIS APAR



APPLIES IS SERVICE PACK SP00, GEN LEVEL 0103.









William M. Allen, Jr.

ARCH Consulting Associates, Ltd.

(704) 641-0296
This e-mail may contain confidential or privileged information. If
you think you have received this e-mail in error, please advise the
sender by reply e-mail and then delete this e-mail immediately.
Thank you. Aetna
"
IDMS Public Discussion Forum
IDMS-L@LISTSERV.IUASSN.COM
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IDMS-L@LISTSERV.IUASSN.COM
IDMS-L@LISTSERV.IUASSN.COM
SMTP








Normal

Normal
Re: [IDMSVENDOR-L] odd problem .....
"Hi Chris,

Do you have the setup of multiple system.ddldml.** but one single
system.ddldclod used by a number of IDMS systems ? I experienced the
same scenario you described before. The possible cause is we may have a
number of systems (e.g. 61, 62, 63) defined in sysgen in the very
beginning and then we decided to clone different IDMS CVs. For each of
the CV, we assign individual system.ddldml file but we're sharing the
same system.ddldclod file.

So when you did your sysgen, it's so easy for you to get into the trap
that you could establish currency of the system, add and generate the
program but in fact it didn't get added into the correct ddldml (if you
have a multiple to them).


Regards,
Tammy Lei
EDS | Australia ADU | Data Engineering Capability - DBA
Level 1, 36-46 George Street, Burwood, NSW 2134
Office: +61 2 9012 5882 | Mobile: +61 421 847 906
Fax: +61 2 9012 6612 | Email: tammy.lei@eds.com

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