OAS 10.1.2 10.1.3 OPMN Spins CPU, Log Files Grow Large Due To Port Conflict e.g. With Database

(Doc ID 297411.1)

Last updated on FEBRUARY 01, 2016

Applies to:

Oracle Fusion Middleware - Version to [Release AS10g to AS10gR3]
Oracle Net Services - Version and later
Oracle HTTP Server - Version to [Release AS10g to AS10gR3]
Information in this document applies to any platform.
Checked for relevance on 23-Aug-2013


Oracle Application Server 10g OPMN is spinning / consuming a high amount of CPU

You may see the ORACLE_HOME/opmn/logs/ons.log (OracleAS 10.1.2) or ORACLE_HOME/opmn/logs/opmn.log (OracleAS 10.1.3) growing large - filling up with lines like: 

missing form factor


Connection 0,,6101 notification header too large


[ons-connect] Passive connection,6100 missing connect
[ons-messages] Connection,6100 invalid notification header

Once CPU consumption passes the host machine's capacity threshold OPMN commands will begin to fail. For you example you may see:

$ORACLE_HOME/opmn/bin/opmnctl status

Unable to connect to opmn.
Opmn may not be up.

The issue can be seen with OPMN running in technology stacks which use:


The issue typically occurs when Oracle Application Server or Oracle HTTP Server reside on the same machine / server as an Oracle Server (Database).


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