This document discusses different options for choosing between Oracle Real Application Clusters (RAC), Standard Edition (SE), and RAC One Node. It provides an overview of Oracle Clusterware and RAC architectures. Standard Edition RAC supports up to 4 sockets and requires ASM, while Enterprise Edition has more scalability and supports third-party clusterware. RAC One Node provides high availability with one database instance and supports server consolidation. The document compares features and considerations for each edition and provides examples of suitable scenarios.

1. RAC - EE, SE, One Node-
How to Choose?
Leighton L. Nelson
VirtaThon 2011

2. About Me
 Senior Oracle DBA with over 10 years experience
 Worked on Oracle 7.3, 8i,9i,10g,11g with RAC &
DataGuard
 Member of IOUG, Brain Surface
 Blogger (blogs.griddba.com)
VirtaThon 2011

3. Agenda
 Oracle Clusterware
 Real Application Clusters Overview
 Standard Edition
 RAC One Node
 Feature Comparison
 RAC Success Factors
VirtaThon 2011

4. Oracle Clusterware Architecture
 Provides cluster membership and high availability
Services for RAC and ASM
 Manages instances, listeners, services, databases etc.
 Clusterware relies on private network and shared disks
for registry and membership details –
interconnect, OCR, Voting Disks
 High Availability API allows for non-Oracle applications
to be managed by Oracle Clusterware
VirtaThon 2011

5. Real Application Clusters
 Provides high availability solution for databases
 A single database which consists of multiple instances
 Provides scalability for applications
 Forms the basis for Oracle’s Grid Computing
 Shared everything architecture
 Requires Oracle Clusterware (10g and higher)
 Can be run on top of third-party Clusterware*
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6. Real Application Clusters
VirtaThon 2011

7. Standard Edition RAC
 From Oracle 10g SE you can use RAC without additional
license
 Restricted to maximum of 4 sockets in cluster
 Requires the use of ASM for all database files
 11gR2 requires the use of ACFS for binaries
 Third-party Clusterware not supported
 Lower cost-entry point than Enterprise Edition
VirtaThon 2011

8. Standard Edition
Advantages/Disadvantages
Advantages Disadvantages
RAC license included Maximum of 4 sockets in cluster
RAC HA features supported Limited scalability
(FAN/TAF/FCF)
Load balancing Limited High Availability
Storage Consolidation (ASM) No third-party Clusterware
Support
Significantly reduced ASM required for datafiles
license/maintenance costs
VirtaThon 2011

9. RAC One Node
 RAC One Node is an option of 11gR2 Enterprise Edition
 Provides High Availability (Failover) of RAC
 Only one instance of DB runs in the cluster at any given
time*
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10. RAC One Node
RAC One Node Failover
If database instance fails then Clusterware will try to
restart it or failover to another server
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11. RAC One Node
Online Relocation
• Second instance started during relocation
• Connections migrated to new instance
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12. RAC One Node
Advantages/Disadvantages
Advantages Disadvantages
Reduced licensing costs Third-party Clusterware not
supported
Server Consolidation Not supported with SE
Rolling DB, OS, Clusterware, ASM Not many support notes
patching and upgrades
Standardized HA deployment
Online upgrade to full RAC
Instance Caging to limit CPU
resources
Elimination of Cache Fusion
VirtaThon 2011

13. RAC Feature Comparison
Features SE EE One Node
Online Yes Yes Yes
Upgrades/Patchin
g
Management Enterprise Enterprise Enterprise
Manager Manager Manager
Clusterware No third-party Third- No third-party
Clusterware. party/Oracle Clusterware
Oracle Clusterware
Clusterware only
Storage Yes (ASM) Yes (ASM) Yes (ASM)
Consolidation
High Availability Yes (Limited) Yes Yes
Workload Yes Yes Yes
Management
Load Balancing Yes (Instance) Yes (Instance) Yes (Server) 2011
VirtaThon
Restrictions Yes No No

14. RAC Success Factors
 Project Guide for Oracle RAC Implementation (10gR2)
 System Test Plan Outline
 Load Testing (Swingbench, Real Application Testing, ORION)
 Swingbench – TPM/Throughput/IOPS/Scalability
 Real Application Testing – Capture & Replay Production
Workload
 ORION – Benchmark Storage IOPS/Latency/Throughput
 RAC: Frequently Asked Questions (Doc ID 220970.1)
 RAC Assurance Support Team: RAC and Oracle Clusterware
Starter Kit and Best Practices (Generic) (Doc ID 810394.1)
VirtaThon 2011

15. RAC Success Factors
 Review Application Behavior in RAC
 Review sequences (CACHE, NOORDER)
 Truncate – Can cause latencies due to checkpointing
 DDL Statements – Generate row cache locks, library cache
locks
 Instrumentation of Code helps with troubleshooting
 Review Application Server Connections
 Third-party JDBC drivers can cause issues with failover
 Connection pooling can help with load balancing
VirtaThon 2011

16. Possible Scenarios
 Commodity servers with maximum of 2 sockets -> SE
 High End Servers, IBM P series, Sun T-series -> EE
 High End/Commodity Servers with more than 2 sockets -
> EE/RAC One Node
 Sub-minute failover – EE/SE
 Maximum Availability Architecture - EE
VirtaThon 2011

17. Summary
 Have clear business requirements for RAC
 Make sure you understand the benefits of each edition
and also thedrawbacks
 You can convert from Standard Edition to Enterprise
Edition
 Consider Standard Edition if you don’t need features
such as AWR/ASH
VirtaThon 2011

18. References
 RAC: Frequently Asked Questions (Doc ID 220970.1)
 RAC Assurance Support Team: RAC and Oracle
Clusterware Starter Kit and Best Practices (Generic)
(Doc ID 810394.1)
 Whitepaper: Oracle Real Application Clusters One Node:
Better Virtualization for Databases
 Whitepaper: Oracle Real Application Clusters (RAC)
11gR2
 “RAC or Not, Here I Come” by RiyajShamsudeen
VirtaThon 2011

19. Questions?
 Website - blogs.griddba.com
 LinkedIn – Leighton Nelson
 Twitter - twitter.com/leight0nn
 Email: leighton.nelson@mercy.net
VirtaThon 2011