Don't retrieve meta-data by default

docs/migrate.rst

@@ -9,6 +9,18 @@ Minimum Python version is 3.8.0
 
 Rally 1.5.0 requires Python 3.8.0. Check the :ref:`updated installation instructions <install_python>` for more details.
 
+Meta-Data for queries are omitted
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Rally 1.5.0 does not determine query meta-data anymore by default to reduce the risk of client-side bottlenecks. The following meta-data fields are affected:
+
+* ``hits``
+* ``hits_relation``
+* ``timed_out``
+* ``took``
+
+If you still want to retrieve them (risking skewed results due to additional overhead), set the new property ``detailed-results`` to ``true`` for any operation of type ``search``.
+
 Runner API uses asyncio
 ^^^^^^^^^^^^^^^^^^^^^^^
 

docs/track.rst

@@ -402,7 +402,7 @@ With the operation type ``search`` you can execute `request body searches <http:
         2. Rally will not attempt to serialize the parameters and pass them as is. Always use "true" / "false" strings for boolean parameters (see example below).
 
 * ``body`` (mandatory): The query body.
-* ``detailed-results`` (optional, defaults to ``true``): Records more detailed meta-data about queries. As it analyzes the corresponding response in more detail, this might incur additional overhead which can skew measurement results. Set this value to ``false`` for queries that return within single digit milliseconds to increase measurement accuracy. This flag is ineffective for scroll queries.
+* ``detailed-results`` (optional, defaults to ``false``): Records more detailed meta-data about queries. As it analyzes the corresponding response in more detail, this might incur additional overhead which can skew measurement results. This flag is ineffective for scroll queries.
 * ``pages`` (optional): Number of pages to retrieve. If this parameter is present, a scroll query will be executed. If you want to retrieve all result pages, use the value "all".
 * ``results-per-page`` (optional):  Number of documents to retrieve per page for scroll queries.
 

esrally/driver/runner.py

@@ -728,6 +728,13 @@ class Query(Runner):
     * `cache`: True iff the request cache should be used.
     * `body`: Query body
 
+    The following parameters are optional:
+
+    * `detailed-results` (default: ``False``): Records more detailed meta-data about queries. As it analyzes the
+                                               corresponding response in more detail, this might incur additional
+                                               overhead which can skew measurement results. This flag is ineffective
+                                               for scroll queries (detailed meta-data are always returned).
+
     If the following parameters are present in addition, a scroll query will be issued:
 
     * `pages`: Number of pages to retrieve at most for this scroll. If a scroll query does yield less results than the specified number of
@@ -765,7 +772,7 @@ async def request_body_query(self, es, params):
         index = params.get("index", "_all")
         body = mandatory(params, "body", self)
         doc_type = params.get("type")
-        detailed_results = params.get("detailed-results", True)
+        detailed_results = params.get("detailed-results", False)
         params = request_params
 
         # disable eager response parsing - responses might be huge thus skewing results

tests/driver/runner_test.py

@@ -1091,6 +1091,7 @@ async def test_query_match_only_request_body_defined(self, es):
         query_runner = runner.Query()
 
         params = {
+            "detailed-results": True,
             "cache": True,
             "body": {
                 "query": {
@@ -1144,6 +1145,7 @@ async def test_query_match_using_request_params(self, es):
         query_runner = runner.Query()
         params = {
             "cache": False,
+            "detailed-results": True,
             "body": None,
             "request-params": {
                 "q": "user:kimchy"
@@ -1246,6 +1248,7 @@ async def test_query_hits_total_as_number(self, es):
 
         params = {
             "cache": True,
+            "detailed-results": True,
             "body": {
                 "query": {
                     "match_all": {}
@@ -1300,6 +1303,7 @@ async def test_query_match_all(self, es):
 
         params = {
             "index": "unittest",
+            "detailed-results": True,
             "cache": None,
             "body": {
                 "query": {
@@ -1355,6 +1359,7 @@ async def test_query_match_all_doc_type_fallback(self, es):
         params = {
             "index": "unittest",
             "type": "type",
+            "detailed-results": True,
             "cache": None,
             "body": {
                 "query": {