-
I am a DBA in Japan. I'm doing TAF implementation now, but I can't understand TAF well.
We have two DB servers(cwdb1,cwdb2), two application servers(cwap1,cwap2) and clients. I use cwap2 for TAF test. The following is tnsnames.ora on cwap2.
# TNSNAMES.ORA Configuration File:/opt/oracle/product/8.1.6/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
CWDB =
(DESCRIPTION =
(FAILOVER = ON)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = xxx.xxx.xxx.x)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = cwdb)
(INSTANCE_NAME = cwdb)
(FAILOVER_MODE =
(TYPE = SELECT)
(METHOD = BASIC)
(RETRIES = 20)
(DELAY = 15)
)
)
)
CWDB1 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = xxx.xxx.xxx.x)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = cwdb)
(INSTANCE_NAME = cwdb)
)
)
While I'm selecting data with SQL/Plus on cwap2, DB server changes. The select sentence of connected SQL*Plus can continuously fatch the data. But if I'm updating the data, the session failed.
Is it the correct action of TAF? Does TAF support an update transation's
failover?
If does please teach me the parameter setting and give me same information about TAF.
Thanks.
-
Hi,
I am also implementing TAF. I do not have an answer to your question, but I have a question of my own for you.
In your experiments, when does TAF occur ? When the oracle instance fails, or when the server on which database is installed fails (reboots for eg) or when the connection between the client and the database fails ?
Please let me know.
Thanks
-
>But if I'm updating the data, the session failed.
>Is it the correct action of TAF? Does TAF support an update >transation's failover?
In version 805 - no, TAF support only cursors (you can continue fetch). I believe in 815 and 816 it is also no.
The reason I think so: it is really expensive to replicate memory(i.e all uncommited session status) from one node(or server) to another.
