Troubleshooting
Problem
Use this document to collect PEX trace data for debugging a high CPU issue.
Resolving The Problem
PEX TPROF traces are used to help isolate which programs/procedures are using the most CPU time. The trace is obtained using Native IBM i commands.
Step 1. Verify that the required Performance Explorer (PEX) PTFs are applied: http://public.dhe.ibm.com/services/us/igsc/idoctor/html/ptfs.html
From an IBM i operating system command line, type the following (Note: An IBM Support Representative might change some of the parameters specified, based on a specific problem being reported):
Step 2. CRTLIB TSXXXXXXX (where XXXXXXX = your Case number)
Step 3. QSYS/ADDPEXDFN DFN(highcpu) TYPE(*TRACE) ADDTHDOPT(*ALL) LSTALLJOB(*NO) INTERVAL(1 *FIXED) MAXSTG(4000000) TRCFULL(*STOPTRC) TRCTYPE(*SLTEVT) JOB(*ALL) TASK(*ALL) SLTEVT(*YES) MCHINST(*NONE) BASEVT((*PMCO *NONE *FORMAT4))Warning: If the ADDPEXDFN command fails with CPFAF10 (definition already exists) then try again using DFN(highcpu2).
Step 4. STRPEX SSNID(RUN1) DFN(HIGHCPU)
Step 5. ENDPEX (no parameters) and press Enter one time.
Refresh and watch the event counter. When the event counter approaches one million (which typically takes three-six minutes), prepare to stop the trace, but do not stop the trace from the ENDPEX screen. Use Step 6 below to end the trace.
Step 6. Submit this command to batch using JOBQ qsys/qsysnomax so it will run immediately:
SBMJOB CMD(ENDPEX SSNID(RUN1) DTAOPT(*MGTCOL) MGTCOL(TSXXXXXXX/*SSNID)) JOB(ENDPEX) JOBQ(QSYS/QSYSNOMAX)
Step 7. Once the Batch job in Step 6 completes, save the data to a savf.
CRTSAVF QGPL/PEXSAVF
SAVLIB LIB(TSXXXXXXX) DEV(*SAVF) SAVF(QGPL/PEXSAVF) TGTRLS(*CURRENT) DTACPR(*MEDIUM)
Step 8. Send the data to IBM. Instructions for Sending Data to IBM i Support: https://www.ibm.com/support/pages/node/644037
The preferred data upload method is QMGTOOLS: FTP Data to IBM
Step 9: Send in a system snapshot by using QMGTOOLS Step 10. (Optional)
If you would like to analyze the data, consider using IBM's iDoctor PEX Analyzer tool or PRTPEXRPT commands from the operating system command line.
To print reports from the i5 operating system command line, run the following: |
Print PEX Report (PRTPEXRPT) command documentation: Print PEX Report (PRTPEXRPT).
To learn more about iDoctor PEX Analyzer, visit:
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Historical Number
587269612
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Document Information
Modified date:
24 October 2024
UID
nas8N1011762