basic handling of db2 issue with ibm support

© 2010 IBM Corporation

Information Management

Basic Handling of DB2 Issue with IBM Support

Anthony Reina - Accelerated Value Specialist

[email protected]



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Agenda :• Introduction – Why, What, and How?

• Using db2fodc for v9.7 for hang/performance issue

• Enabling and setting db2cos (DB2 call out script)

• The db2support

• Collecting db2support with OPT data

• The db2exfmt (access plan)

• Sending files to IBM.

• Related links and documents

• Gotchas

• Question/Answer



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Introduction Why there is a need for an action plan when issues occur?

Avoid confusion due to a standard response procedure.

Problem definition is immediately defined.

Correct diagnostic information is collected based on the issue reported.

Reduce overhead time, improve time to resolution.



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Introduction What information to collect?

Background Information :

- Time when the problem occurred. - Conditions that currently exist on the system. - Any recent changes to the system (ie. HW, SW, others) - Operation/steps leading to the issue. - Steps taken to recover from the issue. - Time when DB2 or system return to normal. - Diagnostic data

Diagnostic Data



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Introduction How to collect diagnostic data?

Type of Issue db2fodc (V9.7)

db2cos db2support OPTIMIZER db2exfmt

All type of issue

Query performance

Query non-performance

Performance

Hang

Timeout/Deadlock



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db2fodc for v9.7

• db2fodc o DB2 First Occurrence Data Capture process.

• Can be used to collect hang and performance issues.

• Diagnostic data collection usage : db2fodc –db <dbname> -<perf, basic> <full, basic>

• Output directory will be in the DIAGPATH directory.

• Can be customized as needed.

• Output directory will have a prefix of “FODC_Perf_<timestamp>_<nodeno>”



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db2fodc for v9.7 Data to be collected BASIC FULL

Snapshot 4 6

Stacktrace aka call stacks 3 5

vmstat 200 200

Iostat 200 200

db2perfcount 0 2

db2trc 0 1

latchtrace 0 0

Data to be collected Value

os_iterations 2

os_sleep 30

db2pdstack_iterations 2

db2pdstack_sleep 120

db2monitor_sleep 60

fullstack_sleep 300

db2trc_size 8mb

ostrc_size 8000000

ostrc_sleep 30

announce_sleep 15

no_wait OFF/ON (Default=OFF)

Data to be collected BASIC FULL

OS Iteration On

db2_config On

basic_db2_config On

more_db2_config On

os_monitor_info On

call_stacks On

db2pd_info On

db2pd_dump On

db2trc On

ostrc On

db2_monitoring On

extra_info On

• db2fodc -perf : refer to TOOLS OPTION of /bin/db2cos_perf

• db2fodc -hang : refer to TOOLS OPTION of /bin/db2cos_hang



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db2fodc for v9.7• Customize the db2fodc –perf full data collection

Before After

Actual Execution



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db2fodc for v9.7• Customize the db2fodc –hang basic to collect db2look.

Before

After



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db2fodc for v9.7• Execute the db2fodc –hang basic command.

db2fodc output

Additional db2look output.



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Enabling and setting db2cos • DB2 Callout Script invoked by default when DB2 cannot continue processing.

• Can be used when diagnostic data is hard to capture (ie. locktimeout, deadlock, sqlcode, or trap).

• The db2cos script can be modified as needed.

• By default it only collects only DB2PD Instance related info.

• The default db2cos scripts is under /bin directory.

• Place modified db2cos scripts under /adm directory. This will be executed first if exist.



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Enabling and setting db2cos

• db2cos example usage :

Copy the /sqllib/bin/db2cos to /sqllib/adm/db2cos Modify db2cos to capture snapshot and db2pd info. Enable –catch flag to trigger db2cos script db2pdcfg –catch -911,2 locktype=V –alldbp db2pdcfg –catch -911,68 locktype=V –alldbp Wait for problem reoccurence To disable : db2pd –catch clear To verify state : db2pd –catch status



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The db2support• Collects environment data from client or server machine.

• Most important utility in collecting information for a DB2 issue.

• The following information is collected : db2diag.log All trap file Locklist files Dump files Buffer pool and table space Various system related files Output from various system commands db2cli.ini

• Command : “db2support . –d <dbname>”

• Output is created on the directory where command is run.

• Output filename is db2support.zip

• Db2support will collect all the files in the DIAGPATH incl. old db2diag.logs.



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Collecting db2support with OPT data and db2exfmt

• Collects additional optimizer (OPT) data.

• Used to investigate optimizer issues.

• Can be invoked via –sf and/or –cl option -sf <SQL file> : SQL filename -cl <0, 1, 2, 3> : Level of info to collect

• Level of information collected : 0 = collects only catalogs and db2look 1 = collect 0 plus db2exfmt 2 = collect 1 plus .db2service 3 = collect 2 plus db2batch

• Commands : db2support . –d <dbname> -sf <SQL file> -cl 1 db2support . –d <dbname> -cl 0

• Output will be part of the db2support.zip called db2supp_opt.zip

-/OPTIMIZER.



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db2support with OPT data enhancements1. Collect optimizer data for different OPTLEVEL including db2batch

information. db2support <output dir> -d <dbname> -c –cl 3 –sf <sql file>

-ol 0,1,2,3,5,7 –extenddb2batch

2. The –basic option collects only optimizer-related diagnostic information.

3. The –extenddb2batch collects db2batch information when –ol and –cl options are used.

4. No db2look and catalog information collected when “-nl | -nodb2look” and “-nc | -nocatalog” options are used.



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The DB2EXFMT (access plan)• Captures information about the access plan, optimizer

inputs, and environment of an SQL query.

• Helps to understand how the SQL query is compiled and executed.

• Shows how configuration parameter changes impact query performance.

• Indispensible tool for query problem determination.

• Explain information includesSequence of operations to process the queryCost informationPredicates and selectivity estimates for each predicateStatistics for all objects referenced in the SQL query at

the time the explain information is captured.



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The DB2EXFMT tool (access plan)• Explain tables must be created before the tool can be used.

SYSINSTALLOBJECTS() procedure – call sysproc.sysinstallobjects(‘EXPLAIN’,’C’,NULL,<schema name>) EXPLAIN.DDL – db2 –tvf …/sqllib/misc/EXPLAIN.DDL

• Using the db2exfmt tool :

db2 set current explain mode explain db2 –tvf <SQL filename> db2 set current explain mode no db2exfmt –d <dbname> -1 –o <output filename> or db2exfmt –d <dbname> -g TIC –w -1 –n –s % -# 0 –o <output

filename>



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Sending files to IBM• Submit files to IBM by using IBM Enhanced Customer Data

Repository (ECuRep) Service site.

• Provides secure and central repository of submitting files to IBM.

• Important Notes :Files must be in a compressed format.Submit files only if a problem record is already opened. IBM may provide information back via ECuRep as well.



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Sending files to IBM• Filename convention : xxxx.bbb.ccc.yyy.yyy

Where :xxxxx = PMR Number bbb = Branch ccc = Country Code

yyy.yyy = Description of the file type.

Example: 34143.055.724.zip

• How to submit files to the ftp server :1.Use a FTP client to connect to ftp.ecurep.ibm.com2.Login as anonymous and enter your email address as the

password.3.Change the directory to /toibm/im4.Change to binary transfer mode for example for a FTP

connection from a Windows command line, enter: bin.5.Upload your file.6.Close your FTP client.



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Important Links/Documents

• Submitting files to IBM via ECuRep

• Collecting Data for DB2 Compiler Issues

• IBM developerWorks

• IBM Support Portal



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Gotchas : Db2support will also collect db2fodc diagnostic data as well.

Collect db2cos data if stored outside the DIAGPATH directory.

Use “db2support…-sf <SQL file> -cl 1” for issues involving one query.

Use “db2support…-cl 0” for issues involviong more than one query.

Use db2exfmt tool to collect query access plan as needed or if more than one query is involved.

Advice support analyst via email once diagnostic files have been sent via ECuRep.



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Questions?