Merge pull request #2036 from edx/feature/gprice/datadog-cs-time

Add comment service request time logging to Datadog

lms/lib/comment_client/utils.py

+from dogapi import dog_stats_api
 import json
 import logging
 import requests
@@ -30,8 +31,14 @@ def merge_dict(dic1, dic2):
 def perform_request(method, url, data_or_params=None, *args, **kwargs):
     if data_or_params is None:
         data_or_params = {}
+    tags = [
+        "{k}:{v}".format(k=k, v=v)
+        for (k, v) in data_or_params.items() + [("method", method), ("url", url)]
+        if k != 'api_key'
+    ]
     data_or_params['api_key'] = settings.API_KEY
     try:
+        with dog_stats_api.timer('comment_client.request.time', tags=tags):
             if method in ['post', 'put', 'patch']:
                 response = requests.request(method, url, data=data_or_params, timeout=5)
             else: