Troubleshooting and Diagnosing Oracle Database 12.2 and Oracle RAC

129 Pages·2017·14.74 MB·English

Troubleshooting and Diagnosing Oracle
Database 12.2 and Oracle RAC
https://www.linkedin.com/in/raosandesh/
sandeshr
Sandesh Rao, Senior Director , RAC Development
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Safe Harbor Statement
The following is intended to outline our general product direction. It is intended for
information purposes only, and may not be incorporated into any contract. It is not a
commitment to deliver any material, code, or functionality, and should not be relied upon
in making purchasing decisions. The development, release, and timing of any features or
functionality described for Oracle’s products remains at the sole discretion of Oracle.
Copyright © 2017,Oracle and/or its affiliates. All rights reserved. | Confidential –Oracle Restricted 2
Common Questions
• How do I contact you ?
– Linkedin – Sandesh Rao
– Email – [email protected]
• Where do I get your presentation ?
– http://otnyathra.in/downloads/
• Which books on RAC do I read for basics or internals ?
– Oracle Database 11g Oracle Real Application Clusters Handbook, 2nd Edition (Oracle Press) 2nd Edition
– Pro Oracle Database 11g RAC on Linux (Expert's Voice in Oracle) 2nd ed. Edition
– Oracle 10g RAC Grid, Services and Clustering 1st Edition
– Pro Oracle Database 10g RAC on Linux: Installation, Administration, and Performance (Expert's Voice in
Oracle) 1st Corrected ed., Corr. 3rd printing Edition
– Oracle Database 12c Release 2 Oracle Real Application Clusters Handbook: Concepts, Administration, Tuning &
Troubleshooting (Oracle Press) 1st Edition
– Documentation – Autonomous Computing Guide , RAC Admin guide
Copyright © 2017,Oracle and/or its affiliates. All rights reserved. | Confidential –Oracle Internal/Restricted/Highly Restricted 3
Agenda
• Architectural Overview
• Troubleshooting Scenarios
• Proactive and Reactive tools
• Q&A
Copyright © 2017,Oracle and/or its affiliates. All rights reserved. |
Grid Infrastructure Overview
• Grid Infrastructure is the name for the combination of
– Oracle Cluster Ready Services (CRS)
– Oracle Automatic Storage Management (ASM)
• The Grid Home contains the software for both products
• CRS can also be Standalone for ASM and/or Oracle Restart
• CRS can run by itself or in combination with other vendor clusterware
• Grid Home and RDBMS home must be installed in different locations
– The installer locks the Grid Home path by setting root permissions.
Copyright © 2017,Oracle and/or its affiliates. All rights reserved. |
Grid Infrastructure Overview
• CRS requires shared Oracle Cluster Registry (OCR) and Voting files
– Must be in ASM or CFS
– OCR backed up every 4 hours automatically GIHOME/cdata
– Kept 4,8,12 hours, 1 day, 1 week
– Restored with ocrconfig
– Voting file backed up into OCR at each change.
– Voting file restored with crsctl
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Grid Infrastructure Overview
• For network CRS requires
– One/multiple high speed, low latency, redundant private network for inter node
communications
– Think of interconnect as a memory backplane for the cluster
– Should be a separate physical network or managed converged network
– VLANS are supported
– Used for :-
• Clusterware messaging
• RDBMS messaging and block transfer
• ASM messaging
• HANFS for block traffic
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Grid Infrastructure Overview
• Only one set of Clusterware daemons can run on each node
• The CRS stack is spawned from Oracle HA Services Daemon (ohasd)
• On Unix ohasd runs out of inittab with respawn
• A node can be evicted when deemed unhealthy
– May require reboot but at least CRS stack restart (rebootless restart)
– IPMI integration or diskmon in case of Exadata
• CRS provides Cluster Time Synchronization services
– Always runs but in observer mode if ntpd configured
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Grid Infrastructure Processes
Agents change everything
• Multi-threaded Daemons
• Manage multiple resources and types
• Implements entry points for multiple resource types
– Start,stop check,clean,fail
• oraagent, orarootagent, application agent, script agent, cssdagent
• Single process started from init on Unix (ohasd)
• Diagram below shows all core resources
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Grid Infrastructure Processes
Level 4a
Level 2a
Level 3
Level 0
Level 4b
Level 1
Level 2b
Copyright © 2017,Oracle and/or its affiliates. All rights reserved. |