! core,akka: separate all akka instrumentation into it's own kamon-akka module, related to #136.

All Akka-related instrumentation and code has been moved to the kamon-akka module,
including the filters for actor, dispatcher and router metrics. Also the following
changes are included:

  - Router Metrics are now working properly, related to #139.
  - Cleanup the log output for this module, related to #142.
  - Some minor cleanups in various tests.

This PR breaks the reporting modules which will need to wait for #141 to be ready to come back
to life.

2 files changed, 85 insertions, 0 deletions

diff --git a/kamon-akka/src/main/resources/META-INF/aop.xml b/kamon-akka/src/main/resources/META-INF/aop.xml
new file mode 100644
index 00000000..46e63f91
--- /dev/null
+++ b/kamon-akka/src/main/resources/META-INF/aop.xml
@@ -0,0 +1,34 @@
+<!DOCTYPE aspectj PUBLIC "-//AspectJ//DTD//EN" "http://www.eclipse.org/aspectj/dtd/aspectj.dtd">
+
+<aspectj>
+  <aspects>
+
+    <!-- Actors -->
+    <aspect name="akka.kamon.instrumentation.TraceContextIntoRepointableActorRefMixin"/>
+    <aspect name="akka.kamon.instrumentation.TraceContextIntoSystemMessageMixin"/>
+    <aspect name="akka.kamon.instrumentation.ActorSystemMessageInstrumentation"/>
+    <aspect name="akka.kamon.instrumentation.TraceContextIntoEnvelopeMixin"/>
+    <aspect name="akka.kamon.instrumentation.MetricsIntoActorCellsMixin"/>
+    <aspect name="akka.kamon.instrumentation.ActorCellInstrumentation"/>
+    <aspect name="akka.kamon.instrumentation.RoutedActorCellInstrumentation"/>
+    <aspect name="akka.kamon.instrumentation.ActorLoggingInstrumentation"/>
+
+    <!-- Dispatchers -->
+    <aspect name="akka.kamon.instrumentation.DispatcherInstrumentation"/>
+    <aspect name="akka.kamon.instrumentation.DispatcherMetricCollectionInfoIntoDispatcherMixin"/>
+
+    <!-- Patterns -->
+    <aspect name="akka.kamon.instrumentation.AskPatternInstrumentation"/>
+  </aspects>
+
+  <weaver>
+    <include within="akka..*"/>
+
+    <!-- For some weird reason ByteString produces a java.lang.VerifyError after going through the weaver. -->
+    <exclude within="akka.util.ByteString"/>
+
+    <!-- Exclude CallingThreadDispatcher, is only for test purposes -->
+    <exclude within="akka.testkit.CallingThreadDispatcher"/>
+  </weaver>
+
+</aspectj>
\ No newline at end of file
diff --git a/kamon-akka/src/main/resources/reference.conf b/kamon-akka/src/main/resources/reference.conf
new file mode 100644
index 00000000..4f742ee6
--- /dev/null
+++ b/kamon-akka/src/main/resources/reference.conf
@@ -0,0 +1,51 @@
+# ================================== #
+# Kamon-Akka Reference Configuration #
+# ================================== #
+
+kamon {
+  akka {
+    # If ask-pattern-timeout-warning is enabled, a WARN level log message will be generated if a future generated by the `ask`
+    # pattern fails with a `AskTimeoutException` and the log message will contain information depending of the strategy selected.
+    # strategies:
+    #   - off: nothing to do.
+    #   - lightweight: logs the warning when a timeout is reached using org.aspectj.lang.reflect.SourceLocation.
+    #   - heavyweight: logs the warning when a timeout is reached using a stack trace captured at the moment the future was created.
+    ask-pattern-timeout-warning = off
+
+    # Default dispatcher for all akka module operations
+    dispatcher = ${kamon.default-dispatcher}
+  }
+
+  metrics.precision {
+    actor {
+      processing-time = ${kamon.metrics.precision.default-histogram-precision}
+      time-in-mailbox = ${kamon.metrics.precision.default-histogram-precision}
+      mailbox-size = ${kamon.metrics.precision.default-min-max-counter-precision}
+    }
+
+    router {
+      routing-time = ${kamon.metrics.precision.default-histogram-precision}
+      processing-time = ${kamon.metrics.precision.default-histogram-precision}
+      time-in-mailbox = ${kamon.metrics.precision.default-histogram-precision}
+    }
+
+    dispatcher {
+      maximum-pool-size {
+        highest-trackable-value = 999999999
+        significant-value-digits = 2
+      }
+      running-thread-count {
+        highest-trackable-value = 999999999
+        significant-value-digits = 2
+      }
+      queued-task-count {
+        highest-trackable-value = 999999999
+        significant-value-digits = 2
+      }
+      pool-size {
+        highest-trackable-value = 999999999
+        significant-value-digits = 2
+      }
+    }
+  }
+}
\ No newline at end of file