European System z Technical Conference – End of Day 3

(Originally posted 2007-04-18.)

Me: Memory Matters in 2007

I was pleased that about 60 people attended this presentation.

Connie Beuselinck: System z9 OSA-Express2 Update and Performance Benchmarks

Network Traffic Analyzer was announced today for QDIO problem determination. It’s exclusive to z9 and OSA-Express2. QDIO Diagnostic Synchronisation (also announced today) allows z/OS to signal to OSA-Express2 to synchronise software (z/OS) and hardware (OSA-Express2) traces.

Also announced today was OSA Dynamic LAN Idle, which is designed to reduce latency and improve performance. This feature, which requires z9 and OSA-Express2, affecting OSA inbound blocking and packing.

Connie had some nice but very busy graphs that show z9 performance vs z990 in this area.

Joan Kelley: Pushing The Limits of Parallel Sysplexes: Bigger, Smaller and Further Apart

CF Level 15 was announced today – increases tasks to 112. Recommend re-running CF Sizer as some structures will increase in size.

CF Level 14 had a reduction in “CF to CF” communication service times for duplexing. She reminded us that CF Level 14 also provided a more realistic view of CF Utilisation.

A customer has a 70GB CF structure for MQ!!!! There have been some improvements to allocation that get the allocation time for structures that big down to 3 minutes.

z/OS Release 8 has a new option – Message-Based Protocol – which reduces read I/O to the Couple Data Set, using XCF signals. You need a new format Couple Data Set and to turn it on with a SETXCF command.

Joan has a good discussion – with measurements – of CF Dynamic Dispatch.

APAR OW51813 adjusted the timing thresholds for CF Request Sync to Async conversion. This adjustment has only happened once.

Bob Rogers: Dealing with more Data, A Sysprog View

A good review of the many things we’ve done to allow disk volumes to get larger, the most recent being:

  • Multiple Subchannel Sets in z/OS 1.6
  • HyperPAV

Published by Martin Packer

I'm a mainframe performance guy and have been for the past 35 years. But I play with lots of other technologies as well.

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