Setting Log Levels for Diagnostic Logging in WebLogic 12.2


Applications and framework libraries running on WebLogic produce logging at various levels: error, warning, information, debug (fine and finer). WebLogic allows us to specify what level of logging should be written to the log files. Under normal circumstances administrators will probably require no more than error or perhaps warning level. In times of problematic behavior when more detailed analysis is required, we may want to switch to finer grained logging output.

It is possible to not only define the logging levels at runtime but to also define the current production log level per logger (corresponding to a package or class)- and have settings inherited to lower levels in the package hierarchy.

This article very briefly shows how to set the logging levels in WebLogic 12c Release 2 – where the interface is just a little different from previous releases. Note: the underlying objective of this article is to prepare logging that will be processed by Oracle Management Cloud – Log Analytics.

Open the Enterprise Manager Fusion Middleware Control console.

The logging levels are not configured at domain level:


But at at (managed) server level. Drill down to the relevant server, amispaas_server1 in this example. Open the dropdown menu at the top, click on Logs and select Log Configuration from the submenu:


The Log Configuration page opens with the Log Levels tab selected. Here we can look for all registered loggers (by package and by class) and for each we can configure the desired current log level (threshold). For example, I configure the finest log level for my custom loggers in the nl package and all its nested packages and contained classes:


After making and applying the changes, these new settings are active immediately and the result can be seen in the log files written to by the odl-handler that is configured for the loggers I have now modified. This handler writes to the managed server’s diagnostics file, at least by default: /u01/data/domains/amispaas_domain/servers/amispaas_server_1/logs/amispaas_server_1-diagnostic.log.Note: you can change the configuration of the odl-handler and thereby change the way logging from loggers is managed and written.

The log messages can also be inspected in the EM FMW Control, from the dropdown menu Logs | View Log Messages.


To search for messages specifically from certain loggers, go through these steps:

* click on Search

* click on Add Fields

* select Module from the list of fields

* enter (part of ) the name of the logger in the Module search field, in this case nl


Press Search.

You will get a list of all log messages from loggers whose names comply with the search condition:



Note: the underlying objective of this article is to prepare logging that will be processed by Oracle Management Cloud – Log Analytics.

About Author

Lucas Jellema, active in IT (and with Oracle) since 1994. Oracle ACE Director and Oracle Developer Champion. Solution architect and developer on diverse areas including SQL, JavaScript, Kubernetes & Docker, Machine Learning, Java, SOA and microservices, events in various shapes and forms and many other things. Author of the Oracle Press book Oracle SOA Suite 12c Handbook. Frequent presenter on user groups and community events and conferences such as JavaOne, Oracle Code, CodeOne, NLJUG JFall and Oracle OpenWorld.

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