Add metric tag to differentiate long-poll and normal request (#653)

Author: longquanzheng

src/main/java/com/uber/cadence/internal/metrics/MetricsTag.java

@@ -32,4 +32,5 @@ public class MetricsTag {
   public static final String WORKER_TYPE = "WorkerType";
   public static final String SIDE_EFFECT_ID = "SideEffectID";
   public static final String CHILD_WORKFLOW_ID = "ChildWorkflowID";
+  public static final String REQUEST_TYPE = "RequestType";
 }

src/main/java/com/uber/cadence/internal/metrics/MetricsTagValue.java

@@ -0,0 +1,23 @@
+/*
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.uber.cadence.internal.metrics;
+
+public class MetricsTagValue {
+  public static final String REQUEST_TYPE_NORMAL = "normal";
+  public static final String REQUEST_TYPE_LONG_POLL = "long-poll";
+}

src/main/java/com/uber/cadence/serviceclient/WorkflowServiceTChannel.java

@@ -96,6 +96,7 @@
 import com.uber.cadence.internal.Version;
 import com.uber.cadence.internal.common.CheckedExceptionWrapper;
 import com.uber.cadence.internal.common.InternalUtils;
+import com.uber.cadence.internal.metrics.MetricsTag;
 import com.uber.cadence.internal.metrics.MetricsType;
 import com.uber.cadence.internal.metrics.ServiceMethod;
 import com.uber.m3.tally.Scope;
@@ -109,6 +110,12 @@
 import com.uber.tchannel.messages.ThriftRequest;
 import com.uber.tchannel.messages.ThriftResponse;
 import com.uber.tchannel.messages.generated.Meta;
+import org.apache.thrift.TException;
+import org.apache.thrift.async.AsyncMethodCallback;
+import org.apache.thrift.transport.TTransportException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.UnknownHostException;
@@ -119,11 +126,9 @@
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
-import org.apache.thrift.TException;
-import org.apache.thrift.async.AsyncMethodCallback;
-import org.apache.thrift.transport.TTransportException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+
+import static com.uber.cadence.internal.metrics.MetricsTagValue.REQUEST_TYPE_LONG_POLL;
+import static com.uber.cadence.internal.metrics.MetricsTagValue.REQUEST_TYPE_NORMAL;
 
 public class WorkflowServiceTChannel implements IWorkflowService {
   private static final Logger log = LoggerFactory.getLogger(WorkflowServiceTChannel.class);
@@ -355,7 +360,14 @@ interface RemoteCall<T> {
   }
 
   private <T> T measureRemoteCall(String scopeName, RemoteCall<T> call) throws TException {
+    return measureRemoteCallWithTags(scopeName, call, null);
+  }
+
+  private <T> T measureRemoteCallWithTags(String scopeName, RemoteCall<T> call, Map<String, String> tags) throws TException {
     Scope scope = options.getMetricsScope().subScope(scopeName);
+    if (tags != null) {
+      scope = scope.tagged(tags);
+    }
     scope.counter(MetricsType.CADENCE_REQUEST).inc(1);
     Stopwatch sw = scope.timer(MetricsType.CADENCE_LATENCY).start();
     try {
@@ -665,17 +677,21 @@ private StartWorkflowExecutionResponse startWorkflowExecution(
   @Override
   public GetWorkflowExecutionHistoryResponse GetWorkflowExecutionHistoryWithTimeout(
       GetWorkflowExecutionHistoryRequest request, Long timeoutInMillis) throws TException {
-    return measureRemoteCall(
-        ServiceMethod.GET_WORKFLOW_EXECUTION_HISTORY,
-        () -> getWorkflowExecutionHistory(request, timeoutInMillis));
+    Map<String, String> tags = ImmutableMap.of(MetricsTag.REQUEST_TYPE, request.isWaitForNewEvent() ? REQUEST_TYPE_LONG_POLL : REQUEST_TYPE_NORMAL);
+    return measureRemoteCallWithTags(
+            ServiceMethod.GET_WORKFLOW_EXECUTION_HISTORY,
+            () -> getWorkflowExecutionHistory(request, timeoutInMillis),
+            tags);
   }
 
   @Override
   public GetWorkflowExecutionHistoryResponse GetWorkflowExecutionHistory(
       GetWorkflowExecutionHistoryRequest request) throws TException {
-    return measureRemoteCall(
-        ServiceMethod.GET_WORKFLOW_EXECUTION_HISTORY,
-        () -> getWorkflowExecutionHistory(request, null));
+    Map<String, String> tags = ImmutableMap.of(MetricsTag.REQUEST_TYPE, request.isWaitForNewEvent() ? REQUEST_TYPE_LONG_POLL : REQUEST_TYPE_NORMAL);
+    return measureRemoteCallWithTags(
+            ServiceMethod.GET_WORKFLOW_EXECUTION_HISTORY,
+            () -> getWorkflowExecutionHistory(request, null),
+            tags);
   }
 
   private GetWorkflowExecutionHistoryResponse getWorkflowExecutionHistory(