Error 3113 in Primary Database while connecting Standby

Sometime you may see following error stack in your primary database alert log file.

Wed May 31 08:02:37 2017 LNS: Attempting destination LOG_ARCHIVE_DEST_2 network reconnect (3113) LNS: Destination LOG_ARCHIVE_DEST_2 network reconnect abandoned Error 3113 for archive log file 9 to 'standby_db' Errors in file D:\ORACLE\11203\diag\rdbms\standby_db\mydb\trace\mydb_nsa2_3544.trc: ORA-03113: end-of-file on communication channel LNS: Failed to archive log 9 thread 1 sequence 61239 (3113)

The reason of this error is usually a network glitch that might hinder shipping of redo log data to the standby database and already established session from primary database to standby database (for redo log shipping) disconnects abruptly which causes ORA-03113 to be logged in the alert log file. During same time, following message may be reported in the alert log file of standby database.

Wed May 31 08:04:03 2017 RFS[32]: Possible network disconnect with primary database

To solve this issue, just check if your standby database is working fine and up and running and accessible from the primary database server. Most of the time this error may be ignored as this is just an informative message to let us know about session disconnection, and session re-establishes as soon as network glitch is gone and standby database is accessible from the primary.