root-doc.txt

== Log Service ==

The Log Service package contains the config files for logging and optional, external applications
(Logstash, Elasticsearch, Kibana) to view and process the log information.

A special logger PrefixedActorLogging is
provided for Akka actors that implement TMT components, such as HCDs and assemblies.
It inserts an [[http://logback.qos.ch/manual/mdc.html MDC]] prefix field into the log, where prefix
is the component prefix, which is made up of the subsystem name, followed by a dot and the rest of the component prefix.

The standard logging framework used here is `slf4j` and `logback`. For packages that require `log4j`
(like OPC UA), there is a bridge: `log4j-over-slf4j` that can be used instead of the log4j dependency.

=== Configuring Logging ===

Applications that wish to log can add this project as a dependency, so that the logback.xml config file
will be found. This configures logging to go to the console and, if the system property "application-name" is
defined, to ${application-name}.log in the current directory.