Split logging doc into scala and java. See #1467

akka-docs/general/index.rst

@@ -7,6 +7,5 @@ General
    jmm
    message-send-semantics
    configuration
-   logging
    addressing
    supervision

akka-docs/java/index.rst

@@ -8,6 +8,7 @@ Java API
 
    untyped-actors
    typed-actors
+   logging
    futures
    dataflow
    stm

akka-docs/java/logging.rst

@@ -0,0 +1,97 @@
+.. _logging-java:
+
+################
+ Logging (Java)
+################
+
+.. sidebar:: Contents
+
+   .. contents:: :local:
+
+How to Log
+==========
+
+Create a ``LoggingAdapter`` and use the ``error``, ``warning``, ``info``, or ``debug`` methods,
+as illustrated in this example:
+
+.. includecode:: code/akka/docs/event/LoggingDocTestBase.java
+   :include: imports,my-actor
+
+The second parameter to the ``Logging.getLogger`` is the source of this logging channel.
+The source object is translated to a String according to the following rules:
+
+  * if it is an Actor or ActorRef, its path is used
+  * in case of a String it is used as is
+  * in case of a class an approximation of its simpleName
+  * and in all other cases the simpleName of its class
+
+The log message may contain argument placeholders ``{}``, which will be substituted if the log level 
+is enabled.
+
+Event Handler
+=============
+
+Logging is performed asynchronously through an event bus. You can configure which event handlers that should 
+subscribe to the logging events. That is done using the 'event-handlers' element in the :ref:`configuration`. 
+Here you can also define the log level.
+
+.. code-block:: ruby
+
+  akka {
+    # Event handlers to register at boot time (Logging$DefaultLogger logs to STDOUT)
+    event-handlers = ["akka.event.Logging$DefaultLogger"]
+    loglevel = "DEBUG" # Options: ERROR, WARNING, INFO, DEBUG
+  }
+
+The default one logs to STDOUT and is registered by default. It is not intended to be used for production. There is also an :ref:`slf4j-java` 
+event handler available in the 'akka-slf4j' module.
+
+Example of creating a listener:
+
+.. includecode:: code/akka/docs/event/LoggingDocTestBase.java
+   :include: imports,imports-listener,my-event-listener 
+
+
+.. _slf4j-java:
+
+SLF4J
+=====
+
+Akka provides an event handler for `SL4FJ <http://www.slf4j.org/>`_. This module is available in the 'akka-slf4j.jar'. 
+It has one single dependency; the slf4j-api jar. In runtime you also need a SLF4J backend, we recommend `Logback <http://logback.qos.ch/>`_:
+
+  .. code-block:: xml
+
+     <dependency>
+       <groupId>ch.qos.logback</groupId>
+       <artifactId>logback-classic</artifactId>
+       <version>1.0.0</version>
+       <scope>runtime</scope>
+     </dependency>
+
+You need to enable the Slf4jEventHandler in the 'event-handlers' element in 
+the :ref:`configuration`. Here you can also define the log level of the event bus. 
+More fine grained log levels can be defined in the configuration of the SLF4J backend
+(e.g. logback.xml). The String representation of the source object that is used when 
+creating the ``LoggingAdapter`` correspond to the name of the SL4FJ logger.
+
+.. code-block:: ruby
+
+  akka {
+    event-handlers = ["akka.event.slf4j.Slf4jEventHandler"]
+    loglevel = "DEBUG"
+  }
+
+Logging thread in MDC
+---------------------
+
+Since the logging is done asynchronously the thread in which the logging was performed is captured in
+Mapped Diagnostic Context (MDC) with attribute name ``sourceThread``.
+With Logback the thread name is available with ``%X{sourceThread}`` specifier within the pattern layout configuration::
+
+  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> 
+    <layout> 
+      <pattern>%date{ISO8601} %-5level %logger{36} %X{sourceThread} - %msg%n</pattern> 
+    </layout> 
+  </appender> 
+

akka-docs/scala/index.rst

@@ -8,6 +8,7 @@ Scala API
 
    actors
    typed-actors
+   logging
    futures
    dataflow
    agents

akka-docs/scala/logging.rst

@@ -1,8 +1,8 @@
-.. _logging:
+.. _logging-scala:
 
-#########
- Logging
-#########
+#################
+ Logging (Scala)
+#################
 
 .. sidebar:: Contents
 
@@ -12,7 +12,7 @@ How to Log
 ==========
 
 Create a ``LoggingAdapter`` and use the ``error``, ``warning``, ``info``, or ``debug`` methods,
-as illustrated in this example in Scala:
+as illustrated in this example:
 
 .. includecode:: code/akka/docs/event/LoggingDocSpec.scala
    :include: my-actor
@@ -23,12 +23,7 @@ For convenience you can mixin the ``log`` member into actors, instead of definin
 
   class MyActor extends Actor with akka.actor.ActorLogging { 
 
-Corresponding example in Java:
-
-.. includecode:: code/akka/docs/event/LoggingDocTestBase.java
-   :include: imports,my-actor
-
-The second parameter to the ``Logging`` or ``Logging.getLogger`` is the source of this logging channel.
+The second parameter to the ``Logging`` is the source of this logging channel.
 The source object is translated to a String according to the following rules:
 
   * if it is an Actor or ActorRef, its path is used
@@ -54,21 +49,16 @@ Here you can also define the log level.
     loglevel = "DEBUG" # Options: ERROR, WARNING, INFO, DEBUG
   }
 
-The default one logs to STDOUT and is registered by default. It is not intended to be used for production. There is also an :ref:`slf4j` 
+The default one logs to STDOUT and is registered by default. It is not intended to be used for production. There is also an :ref:`slf4j-scala` 
 event handler available in the 'akka-slf4j' module.
 
-Example of creating a listener in Scala:
+Example of creating a listener:
 
 .. includecode:: code/akka/docs/event/LoggingDocSpec.scala
    :include: my-event-listener
 
-Corresponding example in Java:
 
-.. includecode:: code/akka/docs/event/LoggingDocTestBase.java
-   :include: imports,imports-listener,my-event-listener 
-
-
-.. _slf4j:
+.. _slf4j-scala:
 
 SLF4J
 =====