CICS Lunch n Learn - How to reduce CICS IA overhead

© 2015 IBM Corporation

CICS LUNCH n LEARNJune 18 2015How to Reduce CICS Interdependency Analyzer Overhead.

Gary AndrewsClient Technical Specialist: CICS [email protected]/in/garyandrews1/en

mailto:[email protected]

CICS Transaction Server V5.2

© 2015 IBM Corporation2

Reduce CICS IA Overhead - Customer Concerns

DEV/TEST Application environment does not accurately reflect production.

Production resources (CPU?) are limited.

Perhaps MLC costs are an issue.



Reduce CICS IA Overhead - Customer Concerns

Or the worst fear:

REGION ABENDS



Reduce CICS IA Overhead

Questions:

What data should you collect ?

Why are you collecting this data ?

Can you collect CICS data one week and MQ, IMS and DB2 the next week ?

Do you have cloned regions ?

Why should you collect ‘detailed’ information ?

How to schedule Interdepedency and Affinity data collection?

You will use CINT administration panels to govern the ‘what’ and ‘hows’.

Use the region override option to collect different data in different regions.



IA Architecture - Collector

5



Reduce CICS IA Overhead – General Options Panel



Reduce CICS IA Overhead-General Options Panel Settings

How can I restrict the amount of data ?

Prefix exclude tables

Program exclude list. Use to exclude programs.

Transaction exclude list. Use to exclude transactions.

Resource prefix list. Use to combine TSQueues and ENQ/DEQ resources

You can have master lists and region lists.

IBM program products prefixes are included in the Program exclude list.

‘DFH’ prefix is included in the Resource prefix list.





If you have CICS IA V5.2, Using Trigger for Task collection can significantly reduce overhead for Interdependency collection only. Trigger for Task collection does not apply to Affinity collection.

1 - All transactions are reviewed for collection. (Default)

2 - Every other transaction is reviewed for collection

3 - Every 3rd transaction is reviewed for collection.

N - Every Nth transaction is reviewed for collection.

Recommendation - 50





Restore data on start – Reload the data space from data in the VSAM files at IA startup

Maintain usage counts – Set to Y only if you absolutely need ‘resource use count’ and

‘last used time stamp’ data. Otherwise, set to N. The Y setting forces massive file updates

increasing CICS IA overhead.



Reduce CICS IA Overhead-Other Subsystems


If you decide to collect DB2 data, please INDEX the SYSIBM.SYSPACKSTMT AND SYSSTMT

TABLES

Only select the options that apply to your environment.



Reduce CICS IA Overhead-SELECTING API’S

What data do you want to collect?

Select Y only for the API commands you want to monitor. Select D (Yes+Detail) for Programs and Files to collect data for Threadsafe Analysis.



Reduce CICS IA Overhead-SELECTING SPI’S

What data do you want to collect?

Select Y only for SPI commands you want to monitor.



When do you want to collect data?

This is the ‘master schedule’ menu. Settings can apply to all regions. Or, configured for

individual regions.

Reduce CICS IA Overhead-Timing Is Everything




Example Schedule




CICS IA Threadsafe Considerations





Collect data during the least busy time where you can get a representative sample of application

activity. The cyclical nature of your applications, and the maintenance schedule, will also

determine when to schedule data collections.

How long do I need to collect data?

Only as long as it takes to collect enough data to understand how your application works!!

You can also stagger the collection of the various data types.

For example, you can collect CICS data one week and DB2, MQ etc. data the following week.




How do you deal with Affinities? Very carefully!

Remember – The Trigger for task Collection value DOES NOT apply to Affinity collection.

Due to the nature of Affinity data, it is more important to collect this data in production.

Recommendation – Record each type of Affinity one at a time.




How do you deal with Affinities? Scheduling Example.

Run Affinity collection for Address CWA for a couple of days to a week. Then run Affinity collection for TS Queue etc.

While running Affinity collection for TS Queue, build your Address CWA Affinity Report in the IA plugin.




How to limit the amount of Interdependency data collected.

Figuring out what data you should monitor.

How to schedule Interdependency data collection to avoid contention among resources.

Which CICA IA options and settings contribute to lower overhead.

How to deal with Affinities.

We Learned How To Reduce CICS IA Overhead By Reviewing…….

CICS Lunch n Learn - How to reduce CICS IA overhead

Software

Transcript of CICS Lunch n Learn - How to reduce CICS IA overhead