..
..                             Vortex Link
..
..    This software and documentation are Copyright 2010 to 2018 ADLINK
..    Technology Limited, its affiliated companies and licensors. All rights
..    reserved.
..
..    Licensed under the ADLINK Software License Agreement Rev 2.7 2nd October
..    2014 (the "License"); you may not use this file except in compliance with
..    the License.
..    You may obtain a copy of the License at:
..                        docs/LICENSE.html
..
..    See the License for the specific language governing permissions and
..    limitations under the License.
..

#######
Logging
#######

The Vortex Link logging system is based on **SL4J** (
`<http://www.slf4j.org>`_ ).

SL4J is an abstraction layer for various logging frameworks (such as
java.util.logging, Log4J, Logback, *etc.*) allowing the end user to
plug in the desired logging framework at deployment time.

The **Logback** framework is embedded in the Vortex Link service
jar and so will be used by default. If you want to use any other
logging framework, you need to add it in the *CLASSPATH* (before the
Vortex Link service jar), as documented in
`<http://www.slf4j.org/manual.html#swapping>`_.

Using the Logback framework, you can change the log level with the
``log.level`` java property. This property accepts the following values:

+ ALL
+ DEBUG
+ ERROR
+ INFO
+ OFF
+ TRACE
+ WARN

Example:

.. code-block:: bash
   
   java -Dlog.level=OFF -jar link-service.jar

By default both Vortex Link services have Logback
configured to produce log messages in the console (*i.e.* ``stdout``).
If you want to change this (for instance to have log messages in a file)
you may define you own Logback configuration file and run the service
with the following command:

.. code-block:: bash
   
   java -Dlogback.configurationFile=<your_file> -jar link-service.jar

For more details on Logback configuration please refer to
`<http://logback.qos.ch/documentation.html>`_.