Some time we come across the issue when trying to connect with database from the application side using apps as a user. This basically requires the listener to be up to make connection with database. We get error similar to
Cannot login to sqlplus using following userid/passwd.
sqlplus apps/apps@dbname.
Gives error
ERROR:
ORA-12547: TNS:lost contact
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Error Messages:
ERROR:
ORA-12547: TNS:lost contact
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Solution:
In this case first check if the database listener is up or now. If the listener is up then check the sqlnet.ora file present in ORACLE_HOME/network/admin also can be reached using the environment variable TNS_ADMIN. This file contains 2 parameters, which restricts login to the database from the other hosts.
tcp.validnode_checking = yes
tcp.invited_nodes=(hostname1, hostname2, … )
This will allow entry from hostname1, hostname2 servers only. So if these values are commented and listener is bounced then this will resolve the issue.
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Thanks for your good paper.
how to set up and using the environment variable TNS_ADMIN?
My database is 64 bit 10gR2 4 node rac in linux and client side is 10gr2 in window 64 bit 2008.
I could connect into other window single instance database. But I could not connect to Linux
RAC database one instance
with lost connect message.
Thanks
My sqlnet.ora file does not have tcp.validnode_checking = yes
tcp.invited_nodes=(hostname1, hostname2, … ) these values.
I set the TNS_ADMIN path but my problem is not resolved..