Support for monitoring group buffer pool residency times
OMEGAMON for DB2® Performance Expert allows you to monitor average residency times in realtime and perform Batch record traces. This enables you to better understand the impact that the new IBM z16 hardware will have on your environment.
The respective Db2 instrumentation changes are in IFCID 230 (Group Buffer Pool Attributes) and IFCID 254 (Coupling Facility Cache Structure Statistics).
BATCH reporting support
The RECTRACE report does support the data and entry residency times as follows:
CONNECT INSTANCE END_USER WS_NAME TRANSACT
CORRNAME CONNTYPE RECORD TIME DESTNO ACE IFC DESCRIPTION DATA
CORRNMBR TCB CPU TIME ID
-------- ----------- ----------------- ------ --- --- -------------- -------------
N/P DB3D6E00F125 N/P N/P N/P
N/P 'BLANK' 03:56:00.69592458 20909 1 254 CF CACHE NETWORKID: R
N/P N/P STRUCT STATS
|---------------------------------------------------------------------------------
|GROUP BUFFER POOL NAME 0 EXPLICIT XI COUNTER 0
|READ HIT 356 CHANGED PAGE WRITE HIT 786
|READ MISS DIRECTORY HIT 87 CLEAN PAGE WRITE HIT 0
|READ MISS ASSIGNMENT SUPPRESSED 0 WRITE MISS CACHE FULL 0
|READ MISS NAME ASSIGNED 192 DIRECTORY ENTRY RECLAIM 0
|READ MISS CACHE FULL 0 DATA ENTRY RECLAIM 387
|SEC-GBP CHANGED PAGE WRITE HIT 0 SEC-GBP DIRECTORY ENTRY 0
|SEC-GBP WRITE MISS CACHE FULL 0 SEC-GBP DATA ENTRY 0
|DATA AREA RESID TIME 0 DATA ENTRY RESID TIME 0
|
|---------------------------------------------------------------------------------
N/P DB3AF9A75148 N/P N/P N/P
N/P 'BLANK' 03:56:00.69600310 20910 2 230 GBP ATTRIBUTES NETWORKID: L
N/P N/P
|---------------------------------------------------------------------------------
|GROUP BUFFERPOOL ID : 0 ERROR FLAGS : X'00'
|ALLOCATED GBPOOL SIZE (4K): 2048 CURRENT DIR TO DATA RATIO : 5
|ACTUAL # OF DIR ENTRIES : 4017 PENDING DIR TO DATA RATIO : 5
|ACTUAL # OF DATA ENTRIES : 801 GBP CHECKPOINT INTERVAL (MIN): 4
|DIRECTORY-ENTRY-RECLAIM : 0 DATA-ENTRY-RECLAIM : 387
|TOTAL-CHANGED : 0 XI-DIRECTORY-ENTRY-RECLAIM : 0
|MODE : SIMPLEX
|SEC-GBP ALLOC : N/A SEC-GBP ALLOC DIRECTORIES : N/A
|DATA AREA RESIDENCY TIME : 0 DATA ENTRY RESIDENCY TIME : 0
|
|QBGBERC : 0 QBGBERS : 0
|---------------------------------------------------------------------------------
Real-time monitoring support
The need to support the data area and data and directory entry residency times spawns the Performance Expert Client interface as well as the E3270 host interface.
For the Performance Expert Client, support is added to the “Global GBP details” section (FCID 254) in the Statistics Details pages (see “Data area Residency time” and “Directory entry Residency time” fields):
Furthermore, the Global Buffer Pool attributes changes are visible in the System Parameter page, subsection “Group Buffer Pools” and then drill down:
From an Enhanced 3270 perspective, the data can be monitored from the System Statistics main workspace by navigating to the Buffer Pool workspace and then selecting the “Group Buffer Pool” tab. On zoom in to the respective Group Buffer Pools select the subtab “Performance Counters” which will show the residency times (see highlighted fields):
For the Global Buffer Pool attributes display, also follow the System Statistics main workspace by navigating to the Buffer Pool workspace and then selecting the “Global Buffer Pool” tab. Upon zoom in to the respective Global Buffer Pool you will see the residency times (see highlighted fields):
