Add tracing support for Apache HttpAsyncClient

money-core/src/main/scala/com/comcast/money/core/concurrent/TraceFriendlyThreadPoolExecutor.scala

@@ -20,6 +20,7 @@ import java.util.concurrent._
 
 import com.comcast.money.core.internal.{ MDCSupport, SpanLocal }
 import com.comcast.money.core.logging.TraceLogging
+import com.comcast.money.core.state.State
 import org.slf4j.MDC
 
 object TraceFriendlyThreadPoolExecutor {
@@ -64,28 +65,19 @@ class TraceFriendlyThreadPoolExecutor(corePoolSize: Int, maximumPoolSize: Int, k
     setRejectedExecutionHandler(rejectedExecutionHandler)
   }
 
-  override def execute(command: Runnable) = {
-    val inherited = SpanLocal.current
-    val submittingThreadsContext = MDC.getCopyOfContextMap
+  override def execute(command: Runnable) {
+    val state = State.capture()
 
-    super.execute(
-      new Runnable {
-        override def run = {
-          mdcSupport.propogateMDC(Option(submittingThreadsContext))
-          SpanLocal.clear()
-          inherited.foreach(SpanLocal.push)
-          try {
-            command.run()
-          } catch {
-            case t: Throwable =>
-              logException(t)
-              throw t
-          } finally {
-            SpanLocal.clear()
-            MDC.clear()
-          }
+    super.execute(new Runnable {
+      override def run(): Unit = state.restore {
+        try {
+          command.run()
+        } catch {
+          case t: Throwable =>
+            logException(t)
+            throw t
         }
       }
-    )
+    })
   }
 }

money-core/src/main/scala/com/comcast/money/core/state/RestoredState.scala

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2012-2015 Comcast Cable Communications Management, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.comcast.money.core.state
+
+/** Represents the restored tracing state. */
+trait RestoredState extends AutoCloseable {
+  /** Reverts the restored tracing state on the current thread */
+  override def close(): Unit
+}

money-core/src/main/scala/com/comcast/money/core/state/State.scala

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2012-2015 Comcast Cable Communications Management, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.comcast.money.core.state
+
+import com.comcast.money.core.internal.{ MDCSupport, SpanLocal }
+import org.slf4j.MDC
+
+object State {
+  private lazy val mdcSupport = new MDCSupport()
+
+  /**
+   * Captures the state of the current tracing span so that it can be restored onto
+   * a separate worker thread.
+   *
+   * {{{
+   *   import com.comcast.money.core.state
+   *
+   *   def doSomethingAsynchronous(executor: ExecutorService) {
+   *     val capturedState = State.capture()
+   *
+   *     executor.submit(new Runnable {
+   *       override def run(): Unit = state.restore {
+   *         // resumes on captured
+   *       }
+   *     })
+   *   }
+   * }}}
+   * @return the captured tracing state
+   */
+  def capture(): State = {
+    val span = SpanLocal.current
+    val mdc = MDC.getCopyOfContextMap
+
+    new State {
+      override def restore(): RestoredState = {
+        mdcSupport.propogateMDC(Option(mdc))
+        SpanLocal.clear()
+        span.foreach(SpanLocal.push)
+        new RestoredState {
+          override def close(): Unit = {
+            MDC.clear()
+            SpanLocal.clear()
+          }
+        }
+      }
+    }
+  }
+}
+
+/** Represents the tracing state that has been captured from another thread */
+trait State {
+  /**
+   * Restores the tracing state on the current thread returning a [[RestoredState]]
+   * that can be used with Java 7+ "try-with-resources" syntax to revert the
+   * restored state.
+   *
+   * {{{
+   *   State state = State.capture();
+   *   // later
+   *   try (RestoredState restored = state.restore()) {
+   *     // do something meaningful here
+   *   }
+   * }}}
+   * @return the restored state
+   */
+  def restore(): RestoredState
+
+  /**
+   * Restores the tracing state on the current thread for the duration of the
+   * function.
+   *
+   * {{{
+   *   val state = State.capture
+   *   // later
+   *   state.restore {
+   *     // do something meaningful here
+   *   }
+   * }}}
+   * @param f the function to invoke
+   * @tparam T the return value of the function
+   * @return the value returned from the function
+   */
+  def restore[T](f: => T): T = {
+    val restoredState = restore()
+    try {
+      f
+    } finally {
+      if (restoredState != null) restoredState.close()
+    }
+  }
+}

money-http-async-client/src/main/resources/reference.conf

@@ -0,0 +1,24 @@
+# Copyright 2012-2015 Comcast Cable Communications Management, LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+money {
+  http-client {
+    metric-names {
+      http-call-duration = "http-call-duration"
+      http-call-with-body-duration = "http-call-with-body-duration"
+      http-process-response-duration = "http-process-response-duration"
+      http-response-code = "http-response-code"
+    }
+  }
+}

money-http-async-client/src/main/scala/com/comcast/money/http/client/HttpAsyncTraceConfig.scala

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2012-2015 Comcast Cable Communications Management, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.comcast.money.http.client
+
+object HttpAsyncTraceConfig {
+  lazy val HttpResponseTimeTraceKey: String = "http-call-duration"
+  lazy val HttpFullResponseTimeTraceKey: String = "http-call-with-body-duration"
+  lazy val ProcessResponseTimeTraceKey: String = "http-process-response-duration"
+  lazy val HttpResponseCodeTraceKey: String = "http-response-code"
+}