Oracle Access Manager (OAM) 11g Common Cause for "Oracle Access Manager Operation Error" "OAM-04020"

(Doc ID 2351492.1)

Last updated on MARCH 13, 2018

Applies to:

Oracle Access Manager - Version 11.1.1.3.0 and later
Information in this document applies to any platform.

Goal

At the highest level there is a communications issue between the OAM Webgate and the OAM server on the OAP channle/port. Everything works until a point is reached were the configuration limits are exceeded and requires a restart to reset these parameters/connections.
There are times when the OAM Server OAP communication (port 5575) with the Webgate can hang, resulting in the end user having issues when trying to authenticate to protected resources. A Common reasons for this is due to the growing connections over a period of time
until the adverse effect is seen; which when this occurs the only solution is to restart the Access server in question.
There are certain circumstances that can occur that cause the various pieces of the OAM Server and its dynamics of handling connections to build up over time due to its design as a passive listener for client messages. A given thread does -not- periodically wake up
and check for any new data on the socket.  Instead a trigger is set to notify the OAM server if a message arrives and the thread just sleeps indefinitely until this happens. If a third party breaks the connection without notifying the OAM components, no further messages are possible, the thread will never wake.

The issue is typically seen/caused due to tuning issues. Tuning - Network conductivity in regards to the communications between the OAM Webgate and the OAM server on the OAP channel/port.
Everything works until a point is reached were the configuration limits are exceeded and requires a restart to reset these parameters.

For for example...
Determined one of the Webgates was creating more than 2500 OAP connections on OAM.
Once they disabled the Webgate, they no longer observed any issues.
Tuned the number of Webgate connections and no longer saw the issue

This note will provide a generic starting point when specific symptoms are seen.

 

 

 

Solution

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