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Sunday, April 15, 2007

TAF, Oracle 10gR2 RAC Service: How to Test TAF?

Testing the Fail over in Real Application Clusters Oracle10gR2 using service:
How to test the Fail-over, if the Client is connected to a RAC database and one of the nodes goes down?
1. Client connected to Database from a SQL Plus session from a remote Workstation.

*********************************************

SQL> show user
USER is "SCOTT"
SQL> select INSTANCE_NAME, INSTANCE_NUMBER from v$INSTANCE;
INSTANCE_NAME INSTANCE_NUMBER
---------------- ---------------
devdb1 1

*********************************************
Checking the User /Client status from a DB Server
SQL> select USERNAME, INST_ID, MACHINE, TERMINAL, STATUS
2 from gv$session where USERNAME = 'SCOTT';
USERNAME INST_ID MACHINE TERMINAL STATUS
--------- ---------- ------------------------------ -------------- --------
SCOTT 1 WORKGROUP\PSDBA03-02 PSDBA03-02 INACTIVE

****************************************
3. On the DB Server, force /Kill the Instance devdb1.
4. The status of the DBInstance devdb1 is down.
Name Type Target State Host
------------------------------------------------------------
ora....SDEV.cs application ONLINE ONLINE rac2
ora....db1.srv application ONLINE OFFLINE
ora....db2.srv application ONLINE ONLINE rac2
ora.devdb.db application ONLINE ONLINE rac2
ora....b1.inst application OFFLINE OFFLINE
ora....b2.inst application ONLINE ONLINE rac2
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2

****************************
5. You can see difference with Normal Service, the SQL plus connection throws a error, but with Client-Side Load balancing and TAF the user connection still exists. For User the fail-over is transparent and can go ahead with his session without the need to reconnect.
SQL> select INSTANCE_NAME from v$instance;
INSTANCE_NAME
----------------
devdb2
SQL> show user
USER is "SCOTT"
This is a simple test for fail-over, with a SQL Plus connections from a remote server.

More notes on Service Deployments
http://download.oracle.com/docs/cd/B19306_01/rac.102/b14197/hafeats.htm#BABHBDJD
 
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