Added documentation about OSGi and EventProcessingMonitor

documentation/src/main/docbook/en-US/reference-guide/2-architecture-overview.xml

@@ -125,6 +125,11 @@
         <para>Axon Framework consists of a number of modules that target specific problem areas of
             CQRS. Depending on the exact needs of your project, you will need to include one or more
             of these modules.</para>
+        <para>As of Axon 2.1, all modules are OSGi compatible bundles. This means they contain the
+            required headers in the manifest file and declare the packages they import and export.
+            At the moment, only the Slf4J bundle (1.7.0 &lt;= version &lt; 2.0.0) is required. All
+            other imports are marked as optional, although you're very likely to need others, like
+                <code>org.joda.time</code>.</para>
         <sect2>
             <title>Main modules</title>
             <para>Axon's main modules are the modules that have been thorouhgly tested and are
@@ -151,13 +156,6 @@
                     JGroupsConnector that is used to connect DistributedCommandBus implementation on
                     these nodes.</para>
             </simplesect>
-            <simplesect>
-                <title>Axon Disruptor CommandBus</title>
-                <para>The SimpleCommandBus implementation provides pretty good performance, but the
-                    Disruptor CommandBus module allows you to squeeze more juice out of the same
-                    CPU. It provides an implementation that uses the Disruptor (a lightweight
-                    high-performance computing framework) to speed up processing.</para>
-            </simplesect>
             <simplesect>
                 <title>Axon AMQP</title>
                 <para>The AMQP module provides components that allow you to build up an EventBus

documentation/src/main/docbook/en-US/reference-guide/6-event-listeners.xml

@@ -152,6 +152,25 @@
                     "order-resolver-ref" attribute can be used to refer to another Order resolver to
                     use.</para>
             </simplesect>
+            <simplesect>
+                <title>Commit Handlers</title>
+                <para>In some cases, you want to know when a cluster has handled a specific event.
+                    For example, when a cluster handles an Event asynchronously, but you need send
+                    an acknowledgement to the sender. Generaly, you are unlikely to require this
+                    feature directly. It is mainly used by infrastructure components.</para>
+                <para>The EventProcessingMonitorSupport interface, which was introduced in Axon 2.1,
+                    defines class capable of notifying subscribed monitors. <code>Cluster</code>
+                    extends this interface, meaning each Cluster implementation must be able to deal
+                    with the Event Processing Monitors. Event Listeners that handle Events
+                    asynchronously, such as the <code>AsyncAnnotatedSagaManager</code> also
+                    implement this interface.</para>
+                <para>To register a Monitor with a Cluster (or Event Listener), call the
+                        <code>subscribeEventProcessingMonitor(...)</code> method. It will be invoked
+                    each time an Event has been successfully handled by that listener (by invoking
+                    the <code>onEventProcessingCompleted</code> method) or when event handling has
+                    failed (by invoking <code>onEventProcessingFailed</code>). A single notification
+                    may contain any number of Events.</para>
+            </simplesect>
         </sect2>
     </sect1>
     <sect1 xml:id="event-listeners">