Multitasking again - determining MT engine count.

[richard.pierce1.1]

Hi all,

 

Having a brain freeze.

 

We're bringing a new machine in (MIPS(1350) MSU(187)) from IBM and multitasking support has come up.

 

ISTR that the proper parameter is # of engines minus 1.  Is that (still) valid?

 

We've 3 engines now and that's down from our previous machine (didn't recognize the change) so the MT paramater is still 3.  Prior to that went from 5 engines (value 4) to 4 engines (value 3).

 

Any thought's are greatly appreciated.

Thanks,

[Legacy User]

Here’s a copy of a technote that comes to mind:

Document ID: TEC479380
Tech Document
Title: Running CA IDMS on a mainframe with multiple engines

Description
Some hardware models such as IBM z9 BC model S07-M04 are comprised of multiple engines. This document discusses the options for how CA IDMS can run on such platforms.
Solution
One of the options for CA IDMS is multitasking. It is implemented (or not) based on the startup parms. If your startup specifies MT=Y, then we will implement multitasking. When multitasking is in place, we will simultaneously use multiple engines/processors (these are the same thing) to process IDMS requests. If multitasking is not implemented, CA IDMS will 'single thread' on any available engine.
CA IDMS will run on any processor that is physically available, to the extent it is able. If multitasking (MT) is not specified, we can run on only processor at a time. If MT is specified, then we will check another parameter: SUBT. Assume you are running on a machine with 6 engines/processors. If you specify MT=Y, and do not specify SUBT=nnn then IDMS will use all 6 processors, if needed, to process work (it's self tuning). If you wanted to limit the number of simultaneous engines/processors to 4 you would specify SUBT=4. In this case, IDMS would use up to 4 engines/processors simultaneously to process its work.
This ability to use any available processor means that IDMS isn't 'linked' or 'assigned' or 'limited' to any particular processor/engine. It's processor-independent, so within the constraints outlined above it will run on any available processor. This is also referred to as not having any processor affinity.


Charles (Chuck) Hardee
Senior Systems Engineer/Database Administration
CCG Information Technology
Thermo Fisher Scientific
300 Industry Drive
Pittsburgh, PA 15275
Direct: 724-517-2633
FAX: [phone]
[e-mail]

From: CA IDMS IUA EIUA Global User CommunityMessage Boards [mailto:[e-mail]]
Sent: Tuesday, June 03, 2014 11:37 AM
To: [e-mail]
Subject: [DBA Issues - Open Forum] Multitasking again - determining MT engine count.


Hi all,

Having a brain freeze.

We're bringing a new machine in (MIPS(1350) MSU(187)) from IBM and multitasking support has come up.

ISTR that the proper parameter is # of engines minus 1. Is that (still) valid?

We've 3 engines now and that's down from our previous machine (didn't recognize the change) so the MT paramater is still 3. Prior to that went from 5 engines (value 4) to 4 engines (value 3).

Any thought's are greatly appreciated.

Thanks,
Posted by:richard.pierce1.1
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CA Communities Message Boards
119170016
[e-mail]
https://communities.ca.com

[richard.pierce1.1]

chuckhardee:

Here’s a copy of a technote that comes to mind: Document ID: TEC479380 Tech Document Title: Running CA IDMS on a mainframe with multiple engines Description Some hardware models such as IBM z9 BC model S07-M04 are comprised of multiple engines. This document discusses the options for how CA IDMS can run on such platforms. Solution One of the options for CA IDMS is multitasking. It is implemented (or not) based on the startup parms. If your startup specifies MT=Y, then we will implement multitasking. When multitasking is in place, we will simultaneously use multiple engines/processors (these are the same thing) to process IDMS requests. If multitasking is not implemented, CA IDMS will 'single thread' on any available engine. CA IDMS will run on any processor that is physically available, to the extent it is able. If multitasking (MT) is not specified, we can run on only processor at a time. If MT is specified, then we will check another parameter: SUBT. Assume you are running on a machine with 6 engines/processors. If you specify MT=Y, and do not specify SUBT=nnn then IDMS will use all 6 processors, if needed, to process work (it's self tuning). If you wanted to limit the number of simultaneous engines/processors to 4 you would specify SUBT=4. In this case, IDMS would use up to 4 engines/processors simultaneously to process its work. This ability to use any available processor means that IDMS isn't 'linked' or 'assigned' or 'limited' to any particular processor/engine. It's processor-independent, so within the constraints outlined above it will run on any available processor. This is also referred to as not having any processor affinity. Charles (Chuck) Hardee Senior Systems Engineer/Database Administration CCG Information Technology Thermo Fisher Scientific 300 Industry Drive Pittsburgh, PA 15275 Direct: 724-517-2633 FAX: [phone] [e-mail] From: CA IDMS IUA EIUA Global User CommunityMessage Boards [mailto:[e-mail]] Sent: Tuesday, June 03, 2014 11:37 AM To: [e-mail] Subject: [DBA Issues - Open Forum] Multitasking again - determining MT engine count. Hi all, Having a brain freeze. We're bringing a new machine in (MIPS(1350) MSU(187)) from IBM and multitasking support has come up. ISTR that the proper parameter is # of engines minus 1. Is that (still) valid? We've 3 engines now and that's down from our previous machine (didn't recognize the change) so the MT paramater is still 3. Prior to that went from 5 engines (value 4) to 4 engines (value 3). Any thought's are greatly appreciated. Thanks, Posted by:richard.pierce1.1 -- CA Communities Message Boards https://communities.ca.com/web/ca-idms-iua-eiua-global-user-community/message-board/-/message_boards/view_message/119167476 [e-mail] https://communities.ca.com

Thanks Chuck,

This begs the question - If you have 4 engines, should you use all 4, or should you use 3?   As I said, I thought the rule-of-thumb was # of engines minus 1.

 

And, how can you tell if you've picked the right number on the parm card.

I noticed an OLD thread talking about if MT was worth it.   I've got LRF and CICS - no ADS.  Does/will MT help me?

 

Thanks again,

Dick