Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 
 Home
 E-mail Us
 Oracle Articles
New Oracle Articles


 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog


 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Analysis
 Design
 Implementation
 Oracle Support


 SQL Tuning
 Security

 Oracle UNIX
 Oracle Linux
 Monitoring
 Remote s
upport
 Remote plans
 Remote
services
 Application Server

 Applications
 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S
upport  
 Development  

 Implementation


 Consulting Staff
 Consulting Prices
 Help Wanted!

 


 Oracle Posters
 Oracle Books

 Oracle Scripts
 Ion
 Excel-DB  

Don Burleson Blog 


 

 

 


 

 

 

 

 

Oracle RAC Database Nodes

Oracle RAC Cluster Tips by Burleson Consulting

This is an excerpt from the bestselling book Oracle Grid & Real Application Clusters.  To get immediate access to the code depot of working RAC scripts, buy it directly from the publisher and save more than 30%.


The next main component is the host or node where the database instance resides. This is the place where the actual database processing takes place. RAC Database system provides scalability and high availability. In order to provide large database computing power and maintain large work load, the number of nodes needs to be extended. Most cluster frameworks today differ in terms of the maximum number of nodes they can handle. Most can support a minimum of 4 nodes today, and some can support hundreds. This will also be driven by scalability objectives and capacity requirements.

The nodes themselves may or may not need to be scalable to provide additional capacity in terms of CPU or memory. Unless one uses an expensive SMP server, scalability will be an issue. The ability to scale both within a machine as well as across machines is often desirable.

Oracle RAC can be implemented on a wide range of servers from a clustered group of single CPU Windows boxes to a cluster of 32-CPU SUN E10000 boxes. One of the more promising architectures for RAC is the blade architecture.

In blade architecture, the servers are inserted into a pre-configured RAC similar to Nuclear Instrumentation Modules (NIM) in a NIM bin. Rather than a horizontal orientation they have a vertical one. Blade servers are essentially self-contained servers that rest on a single backplane. The backplane in a blade array provides power, network, and management connections, reducing cabling and overall component expense. Many blade architectures are hot-plugable, allowing online addition and removal of servers from the cluster.

Linux machines are now able to scale up to 8 CPUs, but the majority of systems are 2 or 4 CPU nodes. SMP scalability in Linux beyond 4 CPU?s is not well proven, so the current Oracle recommendation is to stick with 4-CPU machines. The Blade Servers provide low cost 4-way or 2-way servers for building the large cluster environment.

At the same time, Oracle RAC can also run on platforms that allow sub-setting of CPUs, such as the SUN E10000, E15000, and the HP Superdome. In the case of CPU sub-setting the single server is divided into multiple nodes, each running an instance of Oracle9i RAC.

Server Redundancy

The database resides within a server. The server or host is an important component in the provision of the data service. Any failure in the host system causes the database to go down.

Clustered servers utilize two or more nodes, essentially keeping the extra nodes as standby or sometimes as extra computing power, as in the case of the RAC system. With the help of the additional nodes, the standby node can provide the same database service to the user community. However, when in standby, it loses the performance and scalability level for which it is intended.

Clustering servers assures the administrators and the application users that at least one node is alive. A cluster, in its most general form, comprises two or more interconnected computers that are viewed and used as a single, unified computing resource. By using multiple systems, the impact of the failure of any individual system is kept low by passing the failed system?s workload to the remaining members of the cluster.

The standby node becomes functional, or becomes the primary host, when the failed host is unable to provide any host services. When some of the internal components fail and the failure is non-recoverable without intervention, the server is declared not available or simply failed. This indicates that there is a lot of scope for keeping the internal components safe or redundant.

Before losing the server and resorting to the use of the clustered backup node, there are many things that can be done to keep the components from failing. These methods, which act as the first level of redundancy, will be explored next. Some people call it high availability without clustering. In contrast to clustering, system availability can be improved without adding additional servers.

 


This is an excerpt from the bestselling book Oracle Grid & Real Application Clusters, Rampant TechPress, by Mike Ault and Madhu Tumma.

You can buy it direct from the publisher for 30%-off and get instant access to the code depot of Oracle tuning scripts.

http://www.rampant-books.com/book_2004_1_10g_grid.htm


 

 
��  
 
 
Oracle Training at Sea
 
 
 
 
oracle dba poster
 

 
Follow us on Twitter 
 
Oracle performance tuning software 
 
Oracle Linux poster
 
 
 

 

Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


                    









Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


 

Copyright © 1996 -  2017

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.

Remote Emergency Support provided by Conversational