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Graceful Application Switchover in RAC with No Application Interruption (Doc ID 1593712.1)

Last updated on MAY 19, 2022

Applies to:

Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Oracle Database - Enterprise Edition - Version 12.1.0.1 and later
Information in this document applies to any platform.

Purpose

 This document discusses what is needed to manage a graceful application switchover between RAC nodes with no application interruptions during planned maintenance operations. A graceful application switchover means that sessions are drained from one instance to another without interruption.

NOTE: If the reason for the planned maintenance operation is to patch "Oracle JavaVM Component Database PSU/RU" (OJVM PSU/RU), please follow the steps in MOS Doc ID 2217053.1 instead of this note for Oracle versions up to and including 19.x

 

Scope

 This document is intended for architects, database administrators, and application developers.

 

Details

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In this Document
Purpose
Scope
Details
 Recommended Graceful Application Switchover Procedure
 Prerequisites
 Procedure
 1.  Check current status of the services and related instances to ensure services can be moved successfully
 2.  Stop or relocate services on the node to be maintained
 3.  Disable the service 
 4.  Disconnect long-running sessions after the current transaction completes
 5.  Repeat Steps 2 - 4 for all services affected by the maintenance
 6.  Shutdown the database instance
 7. Perform desired maintenance
 8. Start up instance(s) on the node
 9. Enable services that were previously disabled
 10. Start services that were stopped
 11.  Observe that connections are appearing on the service again
 12.  Repeat for each node / instance to be shutdown for planned maintenance
 Understanding Your Application's Use of Connections
  Services and Application Configuration Best Practices
 Community Discussions

References

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