Oracle Cluster Registry-OCR

• Cluster configuration information is maintained in the OCR. 
• The OCR relies on distributed shared cache architecture for optimizing queries, and clusterwide atomic updates against the cluster registry. 
• Each node in the cluster maintains an in-memory copy of OCR, along with the CRSD that accesses its OCR cache. Only one of the CRSD processes actually reads from and writes to the OCR file on shared storage. This process is responsible for refreshing its own local cache, as well as the OCR cache on other nodes in the cluster. 
• For queries against the cluster registry, the OCR clients communicate directly with the local CRS daemon (CRSD) process on the node from which they originate. When clients need to update the OCR, they communicate through their local CRSD process to the CRSD process that is performing input/output (I/O) for writing to the registry on disk. 
• The main OCR client applications are OUI, SRVCTL, Enterprise Manager (EM), the Database Configuration Assistant (DBCA), the Database Upgrade Assistant (DBUA), Network Configuration Assistant (NETCA), and the ASM Configuration Assistant (ASMCA). 
• The installation process for Oracle Clusterware gives you the option of automatically mirroring OCR. This creates a second OCR file, which is called the OCR mirror file, to duplicate the original OCR file, which is called the primary OCR file. Although it is recommended to mirror your OCR, you are not forced to do it during installation. 

The Oracle Grid Infrastructure installation defines three locations for the OCR and supports up to five. New installations to raw devices are no longer supported.

Oracle Clusterware

Oracle Clusterware is:

• A key part of Oracle Grid Infrastructure 
• Integrated with Oracle Automatic Storage Management (ASM)
• The basis for ASM Cluster File System (ACFS)
• A foundation for Oracle Real Application Clusters (RAC)
• A generalized cluster infrastructure for all kinds of applications

Oracle Clusterware is a key part of Oracle Grid Infrastructure, which also includes Automatic Storage Management (ASM) and the ASM Cluster File System (ACFS).

In Release 11.2, Oracle Clusterware can use ASM for all the shared files required by the cluster. Oracle Clusterware is also an enabler for the ASM Cluster File System, a generalized cluster file system that can be used for most file-based data such as documents, spreadsheets, and reports.

The combination of Oracle Clusterware, ASM, and ACFS provides administrators with a unified cluster solution that is not only the foundation for the Oracle Real Application Clusters (RAC) database, but can also be applied to all kinds of other applications.

Note: Grid Infrastructure is the collective term that encompasses Oracle Clusterware, ASM, and ACFS. These components are so tightly integrated that they are often collectively referred to as Oracle Grid Infrastructure.

What Is Clusterware?

Clusterware is a term used to describe software that provides interfaces and services that enable and support a cluster.

Different cluster architectures require clusterware that delivers different services. For example, in a simple failover cluster, the clusterware may monitor the availability of applications and perform a failover operation if a cluster node becomes unavailable. In a load balancing cluster, different services are required to support workload concurrency and coordination.

Typically, clusterware includes capabilities that:

• •Allow the cluster to be managed as a single entity (not including OS requirements), if desired
• •Protect the integrity of the cluster so that data is protected and the cluster continues to function even if  communication with a cluster node is severed
• •Maintain a registry of resources so that their location is known across the cluster and so that  dependencies between resources is maintained
• •Deal with changes to the cluster such as node additions, removals, or failures • Provide a common  view of resources such as network addresses and files in a file system

What Is a Cluster?

A cluster consists of two or more independent, but interconnected, servers. Several hardware vendors have

provided cluster capability over the years to meet a variety of needs. Some clusters were intended only to provide high availability by allowing work to be transferred to a secondary node if the active node fails. Others were designed to provide scalability by allowing user connections or work to be distributed across the nodes.

Another common feature of a cluster is that it should appear to an application as if it were a single server. Similarly, management of several servers should be as similar to the management of a single server as possible. The cluster management software provides this transparency.

For the nodes to act as if they were a single server, files must be stored in such a way that they can be found by the specific node that needs them. There are several different cluster topologies that address the data access issue, each dependent on the primary goals of the cluster designer.

The interconnect is a physical network used as a means of communication between each node of the cluster. In short, a cluster is a group of independent servers that cooperate as a single system.

Note: The clusters you are going to manipulate in this course all have the same operating system. This is a requirement for RAC clusters.

Oracle Grid Infrastructure

ASM and Oracle Clusterware are installed into a single home directory called the Grid Infrastructure home.

With Oracle Database 11g Release 2, Automatic Storage Management (ASM) and Oracle Clusterware are installed into a single home directory, collectively called Oracle Grid Infrastructure. This directory is referred to as the Grid Infrastructure home. Configuration assistants start after the Oracle Universal Installer interview process and binary installation that configure ASM and Oracle Clusterware. Although the installation is called Oracle Grid Infrastructure, Oracle Clusterware and Automatic Storage Manager remain separate components.

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About us

Oracle 11g: RAC and Grid Infrastructure Administration Accelerated Release 2 NEW                                  Contact US

This Oracle 11g: RAC and Grid Infrastructure Administration Accelerated training teaches you about the Oracle Grid Infrastructure products, including Oracle Automatic Storage Manager (ASM), ASM Cluster File System and Oracle Clusterware. You will also learn to administer the Oracle Clusterware and storage products using both command line utilities and graphical tools using both command line and graphical user interface clients.

Objective

• Understand Oracle Clusterware architecture
• Describe how Grid Plug and Play affects Clusterware
• Describe Automatic Storage Management (ASM) architecture
• Perform Grid Infrastructure installation and create RAC database
• Demonstrate Clusterware management proficiency
• Manage application resources
• Troubleshoot Oracle Clusterware
• Administer ASM Instances and disk groups
• Administer ASM Cluster File Systems
• Install Oracle Database 11gR2 software and create RAC database
• Manage RAC databases
• Manage backup and recovery for RAC
• Determine RAC-specific tuning components
• Configure and manage services in a RAC environment
• Describe high availability architectures

From Oracle Education

          Real Application Clusters Concepts
          Troubleshooting Oracle Clusterware
          Administration of ASM
          Administering ASM Cluster File Systems
          Cloning Grid Infrastructure
          DHCP and DNS Configuration for GNS
          Administering ASM Cluster File Systems
          Administering ASM Files and Directories
          Adding  a node
          Deleting a node


          Real Application Clusters Database Installation

• Oracle RAC Background Processes

          ASM Cluster File System

• Oracle ACFS Command-line Tools for Linux and UNIX Environments
• ASMCMD Volume Management Commands
• Oracle ACFS Command-Line Tools


Administering ASM Instances


• Administration - ASM
• Starting Up an Oracle ASM Instance
• Shutting Down an Oracle ASM Instance
• Setting or Changing Initialization Parameter Values
• Oracle Automatic Storage Management 11g Release 2 (11.2.0.2) New Features
• Configuring Initialization Parameters for Oracle ASM Instances
• Setting Oracle ASM Initialization Parameters

Administering ASM Disk Groups


• Views Containing Oracle ASM Disk Group Information
• Tuning Oracle disk I/O: ASM configuration
• Preferred Read Failure Groups
• Performance and Scalability Considerations for Disk Groups
• Miscellaneous Disk Group Maintenance Enhancements
• Dropping Disk Groups
• Disk Group Attributes
• Creating Disk Groups
• Oracle ASM Disk Groups

        Administering Oracle Clusterware

• To migrate OCR to Oracle ASM using OCRCONFIG
• Restoring Voting Disks
• Assignment of IP Addresses and SCAN
• Clusterware Networking
• Adding, Deleting, or Migrating Voting Disks

        ASM Files, Directories, and Templates

• Oracle file types and Oracle ASM file type tags
• Oracle ASM file components
• Managing Disk Group Templates
• Managing ASM ACL With Command Line Utilities
• Alias Oracle ASM Filename Forms

        Monitoring and Tuning the RAC Database

• RAC and Instance or Crash Recovery
• RAC Performance Tuning Goal
• Cache Coherency
• Cache Fusion Basics

       Oracle Clusterware High Availability

• The Generic Server Pool
• Creating an Application VIP Managed by Oracle Clusterware
• CLUSTER HA Components HA
• Managing Resources in 11g RAC
• Application placement policies
• 
  

      Managing Oracle Clusterware

• Download and Install Patch Updates
• Recommended Postinstallation Tasks
• Patching Oracle RAC in Online Mode
• Adding a new Node
• 
  

     RAC Tuning and Debugging

• Index Leaf Block contention Tuning
• HW enqueue contention
• Component Level Debugging

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