ORA-03135: connection lost contact
OracleWhat does it mean?
A previously established, working session lost contact with the server. A long-running query or an idle connection was cut off because the two sides could no longer reach each other.
Why does it happen?
The server process terminated unexpectedly (ORA-00600/07445, kill, resource limit); a RESOURCE_LIMIT profile terminated the session; an idle connection was dropped by a firewall/load balancer; or there was a network outage/packet loss. Typically occurs with queries that do not respond for a long time or with idle connections.
How to fix it
Search the alert.log and related trace files for why the process died (ORA-00600/ORA-07445?). On the network side, increase the firewall idle timeout and enable dead connection detection with SQLNET.EXPIRE_TIME in sqlnet.ora. Check CONNECT_TIME/IDLE_TIME limits in the user profile. Examine server resource pressure (memory, CPU, PROCESSES).
More from this engine
- ORA-27102out of memory
- ORA-04030out of process memory when trying to allocate N bytes
- ORA-12537TNS:connection closed
- ORA-01033ORACLE initialization or shutdown in progress
- ORA-00600internal error code, arguments: [...]
- ORA-07445exception encountered: core dump
- ORA-01102cannot mount database in EXCLUSIVE mode