Connection string in listener log file for loading balance/failover

Question

Hi Experts,
I have 4 node RAC for oracle 10g2 in rad hate 5.0
We creaed service dbsale ( sale1,2 as pr imary and sale3/4 as available) with loading balance/failover.
The remote user created a local TNS as
localmarket =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 155.206.xxx.xx)(PORT = 1521))
(LOAD_BALANCE = OFF)
(CONNECT_DATA = (SERVICE_NAME = dbsale))
From server side, I saw that user send two request connection string. one fail and another is OK.
It seems that fail connecting come from failover/loading balance from dbsale3?
Why do we get two connection string in listener log file?
Which difference is between two connection string?
Where does system change these connection string?
Thanks for your explaining.
Jim
==============listener.log message
[oracle@sale log]$ cat listener_sale.log|grep pmason
15-SEP-2009 13:52:24 * (CONNECT_DATA=(SERVICE_NAME=dbsale)(CID=(PROGRAM=oracle)(HOST=rock)(USER=test ))) * (ADDRESS=(PROTOCOL=tcp)(HOST=161.55.xxx.xx)(PORT=54326)) * establish * dbsale * 0
15-SEP-2009 13:52:25 * (CONNECT_DATA=(SERVICE_NAME=dbsale)(CID=(PROGRAM=oracle)(HOST=rock)(USER=test ))(SERVER=dedicated)(INSTANCE_NAME=sale3)) * (ADDRESS=(PROTOCOL=tcp)(HOST=161.55.xxx.xx)(PORT=54327)) * establish * dbsale * 12520
15-SEP-2009 13:52:30 * (CONNECT_DATA=(SERVICE_NAME=dbsale)(CID=(PROGRAM=oracle)(HOST=rock)(USER=test ))) * (ADDRESS=(PROTOCOL=tcp)(HOST=161.55.xxx.xx)(PORT=54329)) * establish * dbsale* 0
15-SEP-2009 13:52:47 * (CONNECT_DATA=(SERVICE_NAME=dbsale)(CID=(PROGRAM=oracle)(HOST=rock)(USER=test ))) * (ADDRESS=(PROTOCOL=tcp)(HOST=161.55.xxx.xx)(PORT=54332)) * establish * dbsale * 0
15-SEP-2009 13:52:47 * (CONNECT_DATA=(SERVICE_NAME=dbsale)(CID=(PROGRAM=oracle)(HOST=rock)(USER=test ))(SERVER=dedicated)(INSTANCE_NAME=sale3)) * (ADDRESS=(PROTOCOL=tcp)(HOST=161.55.xxx.xx)(PORT=54333)) * establish dbsale 12520
15-SEP-2009 13:52:49 * (CONNECT_DATA=(SERVICE_NAME=dbsale)(CID=(PROGRAM=oracle)(HOST=rock)(USER=test ))) * (ADDRESS=(PROTOCOL=tcp)(HOST=161.55.xxx.xx)(PORT=54334)) * establish * dbsale * 0
Edited by: user589812 on Sep 16, 2009 7:21 AM

Answer 1

Hi Jim,
I think the best way on this case is create one service with one instance as primary and another 3 as available.
Or use the connect string with two vip addresses, cause the service has two instances and the tnsnames.ora entry has only one.
Cheers,
Rodrigo Mufalani
http://mufalani.blogspot.com