We're seeing this issue in the application server logs. ORA-03135: connection lost contact
I'm just trying to understand what could be the exact reason. The server is online, no changes from OS side, I'm able to connect and run some queries in the Database etc...
When we run huge transactions, we're seeing this error coming up after 15-20 mins from the transaction's start point.
Could you advice any tools, traces I can use to find the exact reason?
This error occur when connecting remotely when a firewall terminates the connection.
To diagnose this you need to Check related OS PID is Still exists..
you can increase the value of the sqlnet.ora expire_time parameter in the sqlnet.ora file
or to check for a expire parameter in a SQL*Plus profile
or setting the parameters sqlnet.inbound_connect_timeout and inbound_connect_timeout_listenername to 0 can stop the ORA-03135 error
Check to see if there is a Network Address Translation (NAT) between the client and server
In Windows, check to see if a Windows firewall is checking for your local connections:
Windows XP -> Control panel -> security -> Tab "Advanced"
Edited by: ambrishr24 on Dec 4, 2012 2:47 PM
Its looking a bit strange as we don't have any firewalls enabled in the communication path: On App server, Database server, Routers etc...
Is there any chance that we could get this kind of issues in the absence of the firewall even?