(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
- MIDAW
Mainframe, Performance, Topics 