How to look at CICS without CICS instrumentation

1. Technical University/Symposia materials may not be reproduced in whole or in part without the prior written permission of IBM.
9.0
© Copyright IBM Corporation 2015
He Picks On CICS
Session z011598
Martin Packer
IBM

2. Abstract
Most customers have a very large number of CICS regions. So
much so that managing them can be a challenge.
This presentation aims to make you more productive in managing
your CICS estate.
In it I describe statistical and topological approaches, using only
Address Space data. I also describe when you need to use
CICS-specific data and how to minimise the effort of doing so.
Note: If this sounds a bit like “DB2 Through My Eyes” it isn't.

3. Introduction

4. Understanding The CICS Landscape Is Important
●
It gets you closer to the business
●
Never a bad thing for IT people
●
Helps you predict and manage for growth
●
CICS regions and applications are unruly little creatures
●
New ones keep popping up
●
Managing hundreds or thousands can be tough
●
So pick on the ones that matter
●
Opportunities for e.g. Mobile Workload Pricing can be lost
●
Performance is often about the interrelationship between
regions
●
And DB2, MQ, IMS etc
●
Availability relies on getting configuration right

5. SMF Spheres Of Concern

6. RMF Workload Manager Perspective

7. Workload Manager CICS Service Class Velocity “Trumpet Curve”
Service Class % Of An Engine, Not Time Of Day

8. - “Production CICS Default”
Goal

9. Goal

11. Service Class Serving
Relationships
Velocity =
Using
Using + Delay
x 100 (%)Velocity =

12. WLM Reporting Classes Need Some Thought
●
Reporting classes don't affect performance
●
Completely independent of service classes
●
You can have up to 2047
●
Can use for grouping service classes, or to break them down
●
Transactions or address spaces
●
Much better numbers than SMF 30:
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Real memory
●
Goal attainment
●
Generally 15 minute RMF interval versus 30 minute SMF 30
●
Data in SMF 72 Subtype 3
●
Recommendations:
●
Use them for groups of similar address spaces
●
Or maybe even individual ones
●
Use them for groups of transactions
●
Use the 32-character description to identify what they are
●
e.g. “Production Internet Regions”
●
e.g. “Mobile enquiry transactions”

13. Understanding The CICS Landscape – From SMF 30

14. Here's Part Of A Spreadsheet I Like To Make – To Get Me Started
Temporary
Storage
Server
Mnemonic?
Sorted By

15. What Seems Like Magic Is SMF 30 Usage Data Section
●
Every IFAUSAGE-registered product provides a section
●
Main fields are:
●
Vendor e.g. “IBM Corporation”
●
Product Name e.g. “DB2”, “CICS”, “MQM MVS/ESA”
●
Product Version e.g. “11.01.00”
●
Product Qualifier e.g. “DB25” or “QP25CICS”
●
Some products fill in CPU:
●
MQ does
●
DB2 doesn't
●
Product Qualifier is key to “topology”
●
My code checks for more than 1 version of e.g. CICS
●
Knowing some laggard regions might help you move them
forwards
●
I want to know whether this is a “CICS 4.1” or “CICS 5.3”
customer
●
Likewise for DB2 and MQ

16. CICS / DB2 Connections – Abusing A Mindmapping Tool

17. Makes More Sense If We See The DB2 Data Sharing Groups
Data Sharing Groups Gleaned From XCF Traffic By IRLM Address Spaces

18. CICS / MQ Connections – Looks Familiar?

19. But Some Regions Don't Go To DB2 or MQ
Some of these address spaces aren't strictly CICS – but I count them as
“part of the family” and want to see them anyway

20. How Do I Glean CICS Region Roles?
●
Roles aren't clear cut anyway
●
We've already seen regions talk to both DB2 and MQ
●
DOR / QOR function already seen to be detected
●
TOR function “does nothing”
●
FOR function from non-trivial EXCP rate
●
Reinforced by 42-6 Data Set Performance
●
Which should show you data sets and their types
●
Other types of “companion” address spaces from program
names:
●
DFHXQMN – Temp Storage Server
●
DFHCFMN – Data Tables Server
●
DFHNCMN – Named Counter Server
●
EYU9XECS – CPSM CMAS
●
CTGBATCH – CICS Transaction Gateway

21. Restart Patterns Matter

22. Inter-Region Traffic
●
XCF default group for CICS is DFHIR000
●
I've never seen any other
●
Used for:
●
Function shipping
●
Asynchronous processing
●
Transaction routing
●
Distributed program link
●
Distributed transaction processing
●
Member name is Applid
●
Job name (R742MJOB), new in 2007, is Region Name
●
Traffic not entirely mapped
●
This region's messages in and out
●
That system's messages in and out
●
Not region
●
“Guessing” game is difficult
●
Note: Messages from a system to itself can largely be ignored
●
Only applies to XCF
●
Not local inter-region communication by other means
●
No breakdown of which usage

23. XCF – A Case Where I “Got Lucky” - System-Level

24. XCF – A Case Where I “Got Lucky” - Member-Level
Probable
TORs

25. One Such Correlation – Hour By Hour

26. So If We're Going To Get Statistical...

27. Taking 1 System's Regions And Looking At CPU
No QR TCB Threat

28. “B” Regions – Across All 4 Systems
I'd Say These
Were Clones

29. SMF 30 Miscellany
●
zIIP usage / eligibility tends to suggest java
●
Though it could be System XML
●
Unix-style I/O in several categories
●
Naming conventions worth gleaning
●
Practice Regular Expressions
●
sift experimental “battery of cascading RegExps” program worked
well for me
●
Virtual storage allocated numbers:
●
24-, 31-, 64-Bit
●
Static within a region's life
●
QR TCB might be discernable after OA39629
●
SMF30_Highest_Task_CPU_Program = “DFHKETCB”
●
SMF30_Highest_Task_CPU_Percent to 1% accuracy

30. When You've Done All That...

31. For A Select Set Of Regions
●
Look At CICS Instrumentation
●
Statistics Trace – SMF 110
●
Monitor Trace – SMF 110
●
Transaction Level
●
Time Buckets and CPU
●
Look At DB2 Instrumentation
●
Accounting Trace – SMF 101
●
Transaction Level
●
Connection Name is CICS Region
●
Middle 4 characters of Correlation ID is transaction name
●
Terminal name and Userid also available
●
Time Buckets and CPU
●
Look At MQ Instrumentation
●
Accounting Trace – SMF 116
●
Transaction Level
●
Time Buckets and CPU

32. z Operational Insights open beta
●
What is it?
– Zero-install, web browser based analysis tool
– 3 working CICS insights to try, with published ideas for
other subsystems
– Displays potential savings, and next steps to achieve them
– and shows how you compare to other users
●
Try zOI for free with your own SMF
– ibm.biz/try-zoi

35. Conclusion

36. The Aims Of This Presentation Have Been To
● Show you the value of a topological approach
● Suggest when statistical methods can help
● Remind you of what Workload Manager and RMF can do to help you manage CICS
performance
● Demonstrate many of the things that SMF 30 can do in managing your portfolio of CICS
regions
● Reduce the effort when going to CICS, DB2 and MQ instrumentation
● By focusing on what regions and subsystems are important
● By enabling you to limit to a subset of clones
● Share some of the things I've done to my analysis code in recent months and years
● Quite a few of these have shown up as blog posts