How to check service failover in RAC system

Question

Hi experts,
We have 4 nodes with oracle 10G2 at redhat. we create some service with failover function. some service is not. total 4 services is in system.
I try to use below SQL to find services failover function.
==
select INST_ID,STATUS, FAILOVER_TYPE, FAILOVER_METHOD, FAILED_OVER
from gv$session group by INST_ID,STATUS, FAILOVER_TYPE, FAILOVER_METHOD, FAILED_OVER;
==
The above SQL does not return each service failover function.
==SQL> select INST_ID,
2 STATUS,
3 FAILOVER_TYPE,
4 FAILOVER_METHOD,
5 FAILED_OVER
6 from gv$session group by INST_ID,
7 STATUS,
8 FAILOVER_TYPE,
9 FAILOVER_METHOD,
10 FAILED_OVER;
INST_ID STATUS FAILOVER_TYPE FAILOVER_METHOD FAILED_OVER
1 INACTIVE NONE NONE NO
4 ACTIVE NONE NONE NO
2 INACTIVE NONE NONE NO
1 ACTIVE NONE NONE NO
4 INACTIVE SELECT BASIC NO
3 ACTIVE NONE NONE NO
2 ACTIVE NONE NONE NO
4 INACTIVE NONE NONE NO
3 INACTIVE NONE NONE NO
9 rows selected
How do we explain about result for failover?
This is a prod system we do not like to make a testing .
Thanks for your help!
JIm
Edited by: user589812 on Sep 14, 2009 9:01 AM

Answer 1

Hello Buddy,
One of your users are using FAILOVER cause values SELECT and BASIC on query output. Another users connected on that moment no able to use FAILOVER probably caused by misconfigured TNSNAMES.ora file. Check it on client or apps server machines.
I hope this help u.
Sample of Tnsnames.ora
PRD =
(DESCRIPTION =
(LOAD_BALANCE = ON)
(FAILOVER = ON)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = RAC1-vip)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = RAC2-vip)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = RAC3-vip)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = RAC4-vip)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = your_service_name)
(FAILOVER_MODE =
(TYPE = SELECT)
(METHOD = BASIC)
(RETRIES = 10)
(DELAY = 1)
Cheers,
Rodrigo Mufalani
http://mufalani.blogspot.com