RAC and Clusterware are complex environments to administer and even more so when there are problems. Learn about various tools and utilities which can be used to troubleshoot, instrument and diagnose these problems.

2. Looking at RAC,
GI/Clusterware Diagnostic Tools
Leighton L. Nelson
Oracle DBA Team Lead (10 yrs experience, 6 years with RAC)
RAC SIG US Events Chair and IOUG Liaison
Session# 373

3. Clusterware & RAC is Complex!

4. Where do I begin?

5. Clusterware, ASM & RAC Diagnostics
• Diagcollection
• Cluster Verification Utility (cluvfy)
• Cluster Health Monitor (CHM)
• Remote Diagnostics Agent (RDA)
• ADRCI/Support Workbench
• OS Utilities

6. Diagcollection
• Gathers and packages Clusterware logs, traces plus OS logs and core files*
• $ORA_CRS_HOME/bin/diagcollection.pl --collect --crshome
$ORA_CRS_HOME (10gR2)
• $GRID_HOME/bin/diagcollection.pl --collect --core|crs|all (11gR2)
• Logs can be filtered by date/time with --adr --beforetime --aftertime
• Allocate enough space in current directory for diagnostic files
• Needs to be run on all nodes in the cluster.
• Limited information collected if not run as root
• In 11.2 diagcollection enhanced to collect ADR and CHM data

7. diagcollection example
[root@oelgrid02 u02]# /u01/app/11.2.0/grid/bin/diagcollection.sh --collect
Production Copyright 2004, 2010, Oracle. All rights reserved
Cluster Ready Services (CRS) diagnostic collection tool
The following CRS diagnostic archives will be created in the local directory:
crsData_oelgrid02_20120225_1723.tar.gz -> logs, traces and cores from CRS home.
Note: core files will be packaged only with the --core option.
ocrData_oelgrid02_20120225_1723.tar.gz -> ocrdump, ocrcheck etc
coreData_oelgrid02_20120225_1723.tar.gz -> contents of CRS core files in text
format
osData_oelgrid02_20120225_1723.tar.gz -> logs from Operating System
Collecting crs data

8. Cluster Verification Utility
• Cluvfy runs in stage mode or component mode
• Can be executed from the Grid Infrastructure Home in 11gR2 or from
installation media
• New resource in 11.2.0.2.0 - ora.cvu
• “cluvfy comp –list” displays components that can be checked
• For standalone cluvfy set CV_HOME CV_JDKHOME and CV_DESTLOC

9. Cluster Verification Utility
• Use stage mode during installation/upgrade
• Use component mode to diagnose components after
Clusterware installation
• Doesn’t diagnose all components e.g. HAIP
• $GRID_HOME/bin/cluvfy
• $INSTALL_DISK/runcluvfy.sh
• New in 11.2.0.3.0 :
cluvfy comp healthcheck

10. Cluster Verification Utility
cluvfy comp –list output

11. Cluster Health Monitor (CHM)
• Cluster Health Monitor (CHM) monitors and collect OS and
clusterware metrics in real-time
• Installed by default in 11.2.0.2+
• Collects metrics at 1 sec interval in 11.2.0.2 and 5 sec interval in
11.2.0.3
• Command Line Interface $GRID_HOME/bin/oclumon
• Collects CHM data using diagcollection.pl --collect --chmos

12. Cluster Health Monitor (CHM)
• Useful for troubleshooting root cause analysis - node
reboots/hangs, instance evictions, performance degradations etc
• OTN version of CHM and 11.2.0.2 version are incompatible. If
you have 11.2.0.2 then you cannot install OTN version.
• Uses OS API to collect metrics reducing overhead
• Clusterware resource called ora.crf
• CHM doesn’t require RAC or Clusterware

13. OS Watcher Black Box
• OS Watcher v4.0 has been renamed to OS Watcher Black Box (OSWbb)
• UNIX shell scripts for monitoring the OS (ps, top, mpstat, iostat, netstat, vmstat)
• Useful for diagnosing OS resource and performance problems, node reboots
• Should run on all nodes in a cluster
• Setup private interconnect monitoring
• Execute startOSWbb.sh arg1 arg2 where arg1=collection frequency and
arg2=retention time
nohup ./startOSWbb.sh 60 48 &

14. OS Watcher Black Box
• Bundled with OS Watcher Black Box Analyzer
(OSWbba)
• Requires Java 1.4.2 or greater
• Correlate OS statistics using the analyzer profile
• Generates graphs and reports for memory, cpu, disk
• Use CLI option to script profile generation for
troubleshooting

15. OS Watcher Black Box

16. OS Watcher Black Box
OSWbb Free Memory Graph

17. RACcheck –
RAC Configuration Audit Tool
• RACCHECK OUTPUT

18. RACcheck –
RAC Configuration Audit Tool
• Assess the configuration of RAC, Clusterware and ASM
• Useful for pre-upgrade and post-upgrade system verification
• Uses “Best Practices” to report configuration problems –
PASS/WARNING/FAIL/INFO
• Generates detailed and summary reports with scorecard

19. Remote Diagnostics Assistant
• The diagnostics tool recommended by MOS
• Collects a wealth of information based on configuration –
OS/Clusterware/Database logs
• Runs AWR/Statspack report for Performance problems
• Generates reports in HTML format

20. Procwatcher
• Debug Oracle & Clusterware processes using
oradebug short_stack or OS debugger (e.g. gdb,
pstack)
• Run as Oracle process owner to debug database or as
root for clusterware processes
• Can be deployed as a Clusterware resource
• Useful for troubleshooting session hangs, severe
performance problems, instance evictions

21. Procwatcher
grid@node1[+ASM1]-/u02 >./prw.sh start all
Wed Feb 25 02:30:26 CDT 2012: Starting Procwatcher
Wed Feb 25 02:30:26 CDT 2012: Thank you for using Procwatcher.
:-)
Wed Feb 25 02:30:26 CDT 2012: Please add a comment to Oracle
Support Note 459694.1
Wed Feb 25 02:30:26 CDT 2012: if you have any comments,
suggestions, or issues with this tool.
Wed Feb 25 02:30:26 CDT 2012: Started Procwatcher

22. ADRCI/Support Workbench
• Automatic Diagnostic Repository (ADR) stores database
diagnostic information
• Package diagnostics files using ADRCI or Support Workbench
• Manages incidents and problems from alert logs
• Enterprise Manager provides GUI interface to ADR called Support
Workbench

23. ADRCI/Support Workbench

24. RACDIAG.SQL
• Gathers debug information for RAC Session Hangs
• One-time data capture
• Performs hanganalyze dumps
• Certain types of hangs will prevent it from running

25. OS Utilities
• truss/strace – trace system calls and signals
• pstack – dump stack trace for process
• pmap/procmap – maps process memory
• nmon/nmon analyzer – collects and analyzes OS stats
• collectl /collectl utils – collects and analyzes OS stats

26. Summary
Tool/Utility Instance Evictions Node reboots Clusterware RAC Performance
Problems
diagcollection ✓ ✓ ✓ ✗
cluvfy ✗ ✗ ✓ ✗
CHM ✓ ✓ ✓ ✓
OSWbb/OSWbba ✓ ✓ ✓ ✓
RDA ✓ ✓ ✓ ✓
RACcheck ✓ ✓ ✓ ✗
Procwatcher ✓ ✗ ✓ ✓
ADRCI/SW ✗ ✗ ✗ ✓

27. MOS Notes
• OS Watcher Black Box User Guide [ID 301137.1]
• OS Watcher Black Box Analyzer User Guide [ID 461053.1]
• Data Gathering for Troubleshooting Oracle Clusterware (CRS or GI) Issues [ID 289690.1]
• CRS 10gR2/ 11gR1/ 11gR2 Diagnostic Collection Guide [ID 330358.1]
• Diagnosability for Oracle Clusterware (CRS or Grid Infrastructure) Component and Resource [ID 357808.1]
• Data Gathering for Troubleshooting RAC Issues [ID 556679.1]
• Cluster Health Monitor (CHM) FAQ [ID 1328466.1]
• Introducing Cluster Health Monitor (IPD/OS) [ID 736752.1]
• RACcheck - RAC Configuration Audit Tool [ID 1268927.1]
• Procwatcher: Script to Monitor and Examine Oracle DB and Clusterware Processes [ID 459694.1]
• Script to Collect RAC Diagnostic Information (racdiag.sql) [ID 135714.1]

28. Contact Information
• Website - blogs.griddba.com
• LinkedIn – Leighton Nelson
• Twitter - @leight0nn
• Email: leighton.nelson@mercy.net