Book Image

Oracle 11g R1 / R2 Real Application Clusters Handbook

Book Image

Oracle 11g R1 / R2 Real Application Clusters Handbook

Overview of this book

RAC or Real Application Clusters is a grid computing solution that allows multiple nodes (servers) in a clustered system to mount and open a single database that resides on shared disk storage. Should a single system (node) fail, the database service will still be available on the remaining nodes. RAC is an integral part of the Oracle database setup: one database, multiple users accessing it, in real time. This book will enable DBAs to get their finger on the pulse of the Oracle 11g RAC environment quickly and easily. This practical handbook documents how to administer a complex Oracle 11g RAC environment. It covers all areas of the Oracle 11g R1 RAC environment, with bonus R2 information included, and is indispensable if you are an Oracle DBA charged with configuring and implementing Oracle11g. It presents a complete method for the design, installation, and configuration of Oracle 11g RAC, ultimately enabling rapid administration of Oracle 11g RAC environments.Packed with real-world examples, expert tips, and troubleshooting advice, the book begins by introducing the concept of RAC and High Availability. It then dives deep into the world of RAC design, installation, and configuration, enabling you to support complex RAC environments for real-world deployments. Chapters cover RAC and High Availability, Oracle 11g RAC Architecture, Oracle 11g RAC Installation, Automatic Storage Management, Troubleshooting, Workload Management, and much more. By following the practical examples in the book, you will learn every concept of the RAC environment and how to successfully support complex Oracle 11g R1 and R2 RAC environments for various deployments in real-world situations.
Table of Contents (20 chapters)
Oracle 11g R1/R2 Real Application Clusters Handbook
Credits
About the Authors
About the Reviewers
Preface

Monitoring RAC-specific wait events, global enqueues, and system statistics


It is crucial to monitor wait events, global enqueues, and system and session statistics as significant waits inevitably indicate a performance problem. If a wait is in the top five list of an AWR report, it needs further investigation by drilling down to the event, that is, the reason of the wait, while bearing in mind that these are global events and all the instances of the RAC cluster are involved.

We need to avoid so called "one node myopia" syndrome and troubleshoot the problem from the concept of RAC as a cluster database with all the instances of the cluster. ADDM, AWR, and ASH reports are instrumental, and most of the time sufficient to start diagnosing and troubleshooting performance problems in RAC. Performance V$ views are also very useful in providing thorough information for troubleshooting and performance tuning.

Each RAC instance takes its own AWR snapshot at approximately the same time. Each instance...