Episode 26 "Sounding Board"

Mainframe, Performance, Topics Podcast - A podcast by Marna Walle

Categories:

Technology

Here are the show notes for Episode 26 "Sounding Board". The show is called this because it relates to our Topics topic, and because we recorded the episode partly in the Pougkeepsie recording studio where Martin sounded zen, and partly at home.

What’s New

  • APAR PH21919: NEW FUNCTION - WORKFLOW SUPPORT SAVE JOB OUTPUT
    • PTF Numbers are UI68359 for 2.3 and UI68360 for 2.4
  • APAR OA56774 (since 2.2) Provides new function to prevent a runaway sysplex application from monopolizing a disproportionate share of CF resources
    • Not based on CF CPU consumption. Is based on deteriorating service times to other structures - which you could measure with SMF 74-4 Coupling Facility Activity data.

Mainframe - z15 FIXCATs

  • IBM.Device.Server.z15-8561.RequiredService: Absolute minimum needed to run on a z15. Usually intent is to keep these PTFs to a minimum - and keep the number of PTFs relatively constant.  <<Correction:  SRB z15 GA1 is here, not Exploitation!>>
  • IBM.Device.Server.z15-8561.Exploitation: Needed for optional functions, and you can decide when you want to use them. This PTF list could grow - if we add new functions
  • IBM.Device.Server.z15-8561.RecommendedService: Usually to fix a defect that is found but haven’t risen up to required. Might want to run an SMP/E REPORT MISSINGFIX to see what’s in this FIXCAT. Might install some, all, or none of the fixes. Might want to be more selective. Based on how much change you want to encounter, versus what problems are fixed
  • By the way there are other FIXCATs you might want to be interested in for z15, e.g. IBM.Function.SYSPLEXDataSharing

Performance - DFSORT And Large Memory

  • A very special guest joins us, Dave Betten, former DFSORT performance lead.
  • Dave talked about DFSORT memory controls
    • DFSORT has historically been an aggressive user of memory
    • Installation defaults can be used to control that
    • But the EXPOLD parameter needs special care - because of what constitutes "old pages", which aren't actually unused.
    • DFSORT Tuning Guide, especially Chapter 3
  • Dave talked about how handy rustling up RMF Overview Reports can be, with several Overview conditions related to memory.
  • Most of the information in this topic is relevant to LPARs of all sizes

Topics - Update on recording techniques

  • Recording of podcast - still using Skype to collaborate
  • Production - Editing - Moved to Ferrite on iPad OS
  • Publishing - same process as before, but on a new publisher!

Customer requirements (assume usual disclaimer)

  • RFE 139477 “Please include the CPU Time Limit for a Job/Step in SMF Type 30”
    • After the fact - End of step looks useful. Could run query comparing to actual CPU time, then track to see if ABEND is on the horizon
  • “ As it happens ” - Would like on the SMF Interval as well as Step End records. May not need the SMF information if vendor and IBM tools already do it today.

On the blog

So it goes...