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Active Memory Pools with Navigator for i

December 21, 2017

On the “green screen” you can see what pool a job is running in with Work with Active Jobs (WRKACTJOB); press F11 one time and you’ll find a column with the pool number. That’s nice, but you need to know the description of the pool that number is associated with. 

Using Work with System Status (WRKSYSSTS), and Work with Shared Storage Pools (WRKSHRPOOL), you can see other information regarding your memory pools, such pool size, faulting rate and other metrics. In addition, there are system values, subsystem descriptions, and APIs that can be used to control the configuration of a memory pool. 

Navigator allows you to easily see all this information in one place via Active Memory Pools.

In Navigator, simply open the Work Management task and click on the Active Memory Pools task. You’ll see your memory pools and some basic information about them, such as the current size, current threads running in the pool, the maximum eligible threads and total faults, as the screen capture below shows.

(Click on image to open full-size file.)

You can customize this view with Actions --> Columns … to select what information you would like to see. This is like a super-duper WRKSYSSTS & WRKSHRPOOL and more.

The columns of information you can display are listed below. (In parenthesis I noted the green screen interface):
  • System Pool Identifier (WRKSHRPOOL, WRKSYSSTS)
  • Pool (name) (WRKSHRPOOL, WRKSYSSTS F11 two times)
  • Description (WRKSHRPOOL)
  • Shared (WRKSHRPOOL will show subsystem and library for private pools)
  • Current Threads
  • Maximum Eligible Threads (WRKSHRPOOL, WRKSYSSTS)
  • Total Faults
  • Active -> Ineligible (WRKSYSSTS, F11)
  • Active -> Wait (WRKSYSSTS, F11)
  • Database Faults (WRKSYSSTS)
  • Defined Size (MB) (WRKSHRPOOL, QMCHPOOL and QBASPOOL system values)
  • Non-database Faults (WRKSYSSTS)
  • Paging Option (WRKSHRPOOL, WRKSYSSTS, F11 three times)
  • Reserved Size (MB) (WRKSYSSTS)
  • Status (active is implied in the WRKSYSSTS interface)
  • Tuning – Maximum Faults (WRKSHRPOOL, F11)
  • Tuning – Maximum Size % (WRKSHRPOOL, F11)
  • Tuning – Minimum Faults (WRKSHRPOOL, F11)
  • Tuning – Minimum Size % (WRKSHRPOOL, F11)
  • Tuning – Priority (WRKSHRPOOL, F11)
  • Tuning – Thread Faults (WRKSHRPOOL, F11)
  • Wait -> Ineligible (WRKSYSSTS, F11)
  • Current Ineligible Threads
  • Database Pages (WRKSYSSTS)
  • Non-database Pages (WRKSYSSTS)
  • Tuning – Minimum Activity Level (Change Pool Attributes (QUSCHGPA) API)
  • Tuning – Maximum Activity Level (QMAXACTLVL, QBASACTLVL system values, Change Pool Attributes (QUSCHGPA) API)
From any memory pool, you can right click on the pool and find options to either view the jobs running in that memory pool or the subsystems that are using that memory pool.

The screen capture below shows all the subsystems using the base pool on my test system. (I have not changed the QCTLSBSD system value from its default setting of QBASE).

The MEMORY_POOL_INFO Service can also return this information. I’ll write about that in a future article.

Posted December 21, 2017 | Permalink