### Log Action Properties

In a message flow, use the log action to construct a message to be logged and to define a set of attributes with which it will be logged.

In the Message Flow Editor, click a log action to display its properties in the Properties view. Use these properties pages to configure the selected log action. The pages are:

- Log
- Comment
- Namespaces
- Variables

The Log page has the following options:

Option | Description
--- | ---
Expression | The message context to be logged through XQuery expressions on context variables. To create or edit an expression, click <Expression> (or the expression_fragment, if one is already defined) to display the XQuery/XSLT Expression Editor.
Note: | The Log action may remove blank spaces in an expression when the message is output to the console or a file. Log action output may be parser dependent.
Annotation | Notes for this log action. These notes are logged along with the result of the previously defined expression.
Severity | The severity of the log message. Options are: Debug - While your application is under development, you might find it useful to create and use messages that provide verbose descriptions of low-level activity within the application. Info -Used for reporting normal operations; a low-level informational message. Warning - A suspicious operation or configuration has occurred but it might not affect normal operation. Error - A user error has occurred. The system or application can handle the error with no interruption and limited degradation of service.

Use the Comment page to add a comment, if desired:

Use the Namespaces page to see a list of defined namespaces or to create a new one.

Use the Variables page to see a list of defined context variables or to create a new one. For more information about context variables, see Message Context in the AquaLogic Service Bus User Guide.