BufferPool HealthCheck for Db2 z/OS is a light weight and fast Db2 for z/OS Local and Group Bufferpool checker. It validates all thresholds that can cause performance degradation.
The Db2 Buffer pools are the central area of Db2. They are used for and by everything and, arguably, they have been forgotten about over the past years. especially the GROUP BUFFERPOOLs have all fallen into the shadows. Afterall, just add some CPs, ZiiPs or some memory and all is well?
So, what does BufferPool HealthCheck for Db2 z/OS then do? It issues -DISPLAY BUFFERPOOL and -DISPLAY GROUPBUFFERPOOL commands, reads the results, computes various values and checks if these values have broken any pre-defined thresholds or not.
If any threshold is broken for a given pool you will see it in the sysout enabling you to fix the problem or at least localize it and then get it properly fixed.
This tool is based upon the internal logic of our SQL WorkloadExpert for Db2 z/OS (WLX) „Bufferpool“ Use Case. In WLX the front end is in Zowe and with one click you can generate the corrective ALTERs.
This HealthCheck freeware is just a simple batch job, therefor it doesn´t require Zowe of course.
It supports Db2 12 and 13 and will be updated whenever a change happens in any future release of Db2 for z/OS.
Here is an example output:
Bufferpool HealthCheck for Db2 z/OS Version 1.1
Starting at 2023-10-24-10:20:24
Data Sharing, Member name SD11 Group attach SD1
BUFFERPOOL BP0 VPSIZE 20000 Bufferpool size 4
Frame boundary
Frame sizing
System residency low
PGFIX(NO) used
Page-ins for read required
System Hit Ratio low
No. of pages written for each write I/O low
Prefetch size is too low
VPSEQT should be changed
GROUPBUFFERPOOL GBP0 SIZE 16 MB
GBP Hit ratio too low
GBP Reclaims for directory entries
GBP XI due to directory reclaims
GBP Sync read XI miss ratio high