Re: Reducing ODBC connection impact

Hello Jim,

Am 30.12.2019 um 17:44 schrieb midrangel@xxxxxxxxxxxxxxxxx:

Getting to know how the memory pools (each has a very different role) interact may be slightly daunting at first, however once you understand it, it's really quite easy. It's a bit unfortunate that the names are so similar but once you process it, it will be clear. (You are not alone, almost every PowerUp conference I go to I wind up spending quite some time helping folks understand this concept)

I think so. I'll keep reading the chapters in work management and finally hope that sometime my bulb lights up. ;-) Still a few days off work left…

There are two absolutely required shared pools: *MACHINE and *BASE.
*MACHINE is where IBM I, and 90% of it's parts run.
*BASE is the default shared pool.
IBM provides a total of 64 shared pools: *MACHINE, *BASE, *INTERACT, *SPOOL, and 60 shared pools.

If the system were in restricted state, then all the memory not assigned to *MACHINE will be in *BASE.

As each of the shared pools is used, the system will allocate memory from *BASE to that shared pool, in this case *SHRPOOL1

That's what I deducted from using the system and was confirmed largely by the work management book. Thanks for elaborating, though!

Using *BASE as the first subsystem memory pool is a best practice since that is where the subsystem job gets it's memory and activity level. That way the subsystem can act with the job queues assigned to it, start/stop jobs without having to fight with the application programs running in that subsystem.

I understand. Interesting remark! Thanks!

If the autotune function is turned on (system value: QPFRADJ) then the system monitors faulting/paging and adjusts the system as necessary. For most workloads this works well. In more advanced systems manual is better.

I think so. I set QPFRADJ to 3, so adjustments are based on what's running, not what's deducted at IPL time. I also set paging in wrkshrpool to *CALC. To me, this should enable the system to adjust itself to what IBM thinks is best.

As to my memory, sadly it's not as good as POWER System is, but even after nearly 40 years of doing this some things have stuck, thanks.

I guess it's harder to forget about stuff which was important for an extended amount of time.

:wq! PoC

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