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A fresh look at PERFM IFCIDs - Ones you want 24x7 (A05)

Topic: 2009 NA

Subtopic: DB2 for z/OS



DATE: 2009-5-13 (09:45 AM - 10:45 AM)
SPEAKERS: Terry Berman (DST Systems Inc.)

DB2s Instrumentation Facility (IFI) can record a wide variety of "IFCIDs", detailing low-level and high-level "events" occurring within DB2. Infrequent but important ones are our target here; Utilities, commands, timeouts, mini-PLAN, RLF exceptions, query parallelism all provide indispensable information with low overhead. This presentation shows how to identify the IFCIDs you need and trace them in a practical way, aided by V9s TRACE enhancements. DB2PMs reports are useful, but much better use can be made of the information by processing the records programmatically using REXX (sample elaborated) and SAS /MXG, in order to load historical repositories for diagnostics and trending. A case study dealing with a recent (INSERT) performance issue at DST Systems additionally demonstrates the diagnostic power of low-level PERFM traces used selectively.

EXP. LEVEL: Intermediate,Advanced

OBJECTIVES:

TRACES AND IFCIDS (DSNWMSGS deep-dive. Overhead? Alternatives: DB2 monitor, messages)

HOW TO TRACE (V9 trace enhancements. 24x7: starting IFCIDs at DB2 startup. Collecting the data. Real-time options?)

PROCESSING IFCIDS (Monitor reports. SMF record format, REXX programming, SAS/MXG solution.)

CASE STUDIES EXPLOITING IFCID INFORMATION (Keeping a record of: utilities, commands, mini-plans, parallelism, ...)

INSERT/HIGH-GETPAGE DIAGNOSTICS (Performance issue reported to IBM. Sandbox measurements with selective IFCIDs reproduced and verified fix.)



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