Good day friends…
Today when going through regular activities like alert log checking, i found the following warning in one of database
Tue Jun 15 14:44:55 2010
WARNING: inbound connection timed out (ORA-3136)
Also, following entry was there in sqlnet.log file
Fatal NI connect error 12170.
TNS for 64-bit Windows: Version 10.2.0.2.0 – Production
Oracle Bequeath NT Protocol Adapter for 64-bit Windows: Version 10.2.0.2.0 – Production
Windows NT TCP/IP NT Protocol Adapter for 64-bit Windows: Version 10.2.0.2.0 – Production
Time: 15-JUN-2010 12:58:20
Tracing not turned on.
Tns error struct:
ns main err code: 12535
TNS-12535: TNS:operation timed out
ns secondary err code: 12606
nt main err code: 0
nt secondary err code: 0
nt OS err code: 0
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=188.8.131.52)(PORT=3741))
To my surprise, in next 2 min i got a ticket stating user is facing problem in connecting to database. After waiting for long time, user is getting error in connection establishment.
After analysis, i found following
user connectivity time bound is 60 sec from 10.2 which means oracle will try to establish connection for 60 seconds, once it crosses that limit, it will send error to user process.
This error you will not see in 10.1 version, because in that version time bound limit in infinite.
I did following which resolved my problem
1) Add following entires in listener.ora file on database server
alternatively you can also do this
lsnrctl> set inbound_connect_timeout=0
2) add following entries in sqlnet.ora of database server
we are setting time bound limit to infinite using above parameters. you need to reload the listener after performing above changes using
$ lsnrctl reload
Note : Always take backup of listener.ora or sqlnet.ora files before modifying anything inside
More about this error, you can check in metalink docs 465043.1 and 345197.1
Sometimes, this problem will also occur if you have firewall restrictions. So please check from that end too.