ORA-03113 End of File on Communication Channel

Last week we had a problem with the annoying error message - ORA-03113 end of file on communication channel. Usually the users will run reports that will take 3 to 4 hours. Since last week they were not able to run the reports, it terminated with the error ORA-03113.

There was no error reported in the alert log file and no trace file generated. I even tried to alter the value of SQLNET.ORA parameter sqlnet.expire_time, but nothing worked.

The network was fine and there is no DBLINK in the database.

After much diagnosis and discussion with the networking people, i found the error was due to the timeout connection setting in the firewall. We changed the value from 1 hr to 5 hr and now we are not facing the error.

How to solve ORA-03113 Error

It occurs because the connection between client and server process was broken. We need to find out why the connection got broken.There are many reasons for that. Use the following steps to find out the possible reason.

Step 1: Look for the Alert log file for any error message. If the ORA-03113 error is reported in the alert log it will be accompanied by any othererror message. For example Oracle internal error, or server down etc etc etc.. try to solve that issue. If there is no error in the alert log or no trace file generated then it may not be due to a database error.

Step 2: Look for listener.log file size. If the file size is too large, try to stop the listener, create a new listener.log and restart the listener.

$ LSNRCTL STOP
$ mv listener.log listener_old.log
$ LSNRCTL START ( This will create a new listener.log file).

Step 3: Check for network issues. Ping the server. Check for any protocol error. Get the help of networking people in resolving these errors.

Step 4: Firewall error. There is a setting in the firewall namely, connection timeout, look for the value in this setting. Change to higher valueand check. One way to find whether the error is due to firewall setting is open a telnet session simultaneously and leave it idle till your report runs or returns error. Then try to issue any command in the telnet if the session hangs and you are not able to type the command then the error is due to the firewall setting.

Step 5: If none of the above step works. Contact Oracle Support.