Identify Root Causes of Coupling Facility Configuration Issues

This video demonstrates how you can identify performance issues and root causes for issues in your z/OS Coupling Facility configuration. Addressing these issues could save you precious CPU.

Doing more for less money is the goal of every business, and this case clearly shows to achieve that.

What is a Coupling Facility?

A coupling facility is a piece of hardware that enables processors to communicate. The coupling facility is designed to be much faster for data access than going to physical storage.

Sometimes, a coupling facility runs so well that performance analysts do not regularly monitor and report on the performance of the underlying structures. However, individual structure performance is important to the workload using the structure as well as the overall system.

Sync Service Time Issues

In the case demonstrated in the video, when we loaded RMF data for a customer, we noticed that several structures had warnings for Sync Service Time and Async Service Time.

The customer was not aware that there was a performance problem for any of the structures, but as we saw, many structures were getting worse than 20 microseconds, which was the initial threshold set by IntelliMagic Vision.

We then found that the structure’s synchronous service time was very high for the entire time period.

Delaying Expensive CPU Upgrades

Investigation led to the fact that coupling facilities were being shared which was causing the high service times. A dynamic change was implemented to the coupling facility to use the parameter “Dyndisp=Thin” which had dramatic results.

Besides the obvious result of the structure getting better service times, the “real” CPU cycles spent waiting on the synchronous service requests dropped dramatically as well. This will allow the customer to delay an expensive CPU upgrade.

Sign Up for a Free Trial

Experience firsthand the deepest visibility into your z/OS systems, processors, network, disk and tape environments. Whether you’re in the early stages of product research, evaluating competitive solutions, or trying to solve a problem, we’re happy to help you get the information you need to move forward with your IT initiatives.

Related

Video

Coupling Facility Request Rate: Automated Change Detection Use Case 5

Key coupling facility performance metrics at the structure level include synchronous and asynchronous request rates and service times, making them attractive candidates for Change Detection.

Watch video
Video

Db2 Getpage Rate: Automated Change Detection Use Case 4

“Getpages” are a primary indicator of Db2 activity, reflecting the count of operations to access data in a page. This use case illustrates the identification of a significant increase of Getpages.

Watch video
Video

CPU by WLM Importance Level: Automated Change Detection Use Case 2

Leveraging context-sensitive drilldowns, based on an unanticipated finding of a spike in CPU consumption for the highest importance “Systems” work, this video investigates the address space(s) driving that.

Watch video

Go to Resources

Supported Areas in IntelliMagic Vision for z/OS

Monthly License Charges (MLC)

Tune your processor configuration to increase the MIPS you get out of your mainframe hardware.

Learn More

Coupling Facility

Configure Coupling Facilities for optimal availability and proactively identify hidden health and performance risks

Learn More

Db2

See Buffer Pool imbalances and proactively identify upcoming risks to your Db2 health and performance

Learn More

CICS Transactions

Save time looking for problems and profile CICS transaction data and see transaction response time

Learn More

zEDC Cards

Ensure sufficient capacity and consistent performance for IBM zEDC availability.

Learn More

TCP/IP

Monitor the health of your TCP/IP and analyze traffic from different perspectives.

Learn More

Show all

Other Supported Environments

z/OS Disk and Replication

Early warning system that automatically identifies I/O issues in the making in your disk storage system and replication architecture.
Learn More

z/OS Virtual Tape

Performance and availability management for Virtual and Physical Tape, with specific support for IBM TS7700 and Oracle VSM tape solutions.
Learn More

SAN Storage and Fabric

IntelliMagic Vision collects performance and configuration information on the VMware, fabric and storage systems to provide a complete and end-to-end picture.
Learn More