Add PERCENTILES_TO_CHART param in stats.py to make the Response Time …

…Chart configurable (#2313)

* Added command line parameters to speciufy percentiles for chart

Percentiles were originally 50% and 95%. Command line parameter can
specify chart and report percentiles. Defalt value is 50% and 95%.

* Added new command line argument --percentiles

Old parameters --percemtile1 and percentile2 were removed.
Added test case in test_main for -percentiles parameter

* Updated format by black

* Updated web.py format by black

* Removed command line argument for percentiles and test

Updated to get percentiles info from stats.py::

* Added test in test_main. Updated response_time_percentile variable name

* updated response_time_percentile variable name.

* Fixed stats.py format and test_main.py unnecessary comment out

* Grouped stats import and reorderd response_time_percentile variable in
javascript and html file

Modified test in test_main.py

* updated report.html and locust.js "% percentile" to "th percentile" in
response time chart

* updated percentiles related test in test_main.py

* reformated test_main.py

* change order of PERCENTILES_TO_CHART param

docs/configuration.rst

@@ -201,4 +201,6 @@ The list of statistics parameters that can be modified is:
 +-------------------------------------------+--------------------------------------------------------------------------------------+
 | PERCENTILES_TO_REPORT                     | The list of response time percentiles to be calculated & reported                    |
 +-------------------------------------------+--------------------------------------------------------------------------------------+
+| PERCENTILES_TO_CHART                      | The list of response time percentiles for response time chart                        |
++-------------------------------------------+--------------------------------------------------------------------------------------+
 

locust/html.py

@@ -4,6 +4,7 @@
 import datetime
 from itertools import chain
 from .stats import sort_stats
+from . import stats as stats_module
 from .user.inspectuser import get_ratio
 from html import escape
 from json import dumps
@@ -94,6 +95,8 @@ def get_html_report(environment, show_download_link=True):
         show_download_link=show_download_link,
         locustfile=environment.locustfile,
         tasks=dumps(task_data),
+        percentile1=stats_module.PERCENTILES_TO_CHART[0],
+        percentile2=stats_module.PERCENTILES_TO_CHART[1],
     )
 
     return res

locust/main.py

@@ -100,6 +100,24 @@ def main():
             user_classes[key] = value
             available_user_classes[key] = value
 
+    if len(stats.PERCENTILES_TO_CHART) != 2:
+        logging.error("stats.PERCENTILES_TO_CHART parameter should be 2 parameters \n")
+        sys.exit(1)
+
+    def is_valid_percentile(parameter):
+        try:
+            if 0 < float(parameter) < 1:
+                return True
+            return False
+        except ValueError:
+            return False
+
+    for percentile in stats.PERCENTILES_TO_CHART:
+        if not is_valid_percentile(percentile):
+            logging.error(
+                "stats.PERCENTILES_TO_CHART parameter need to be float and value between. 0 < percentile < 1 Eg 0.95\n"
+            )
+            sys.exit(1)
     # parse all command line options
     options = parse_options()
 
@@ -179,6 +197,7 @@ def main():
 
     # create locust Environment
     locustfile_path = None if not locustfile else os.path.basename(locustfile)
+
     environment = create_environment(
         user_classes,
         options,

locust/static/locust.js

@@ -219,8 +219,8 @@ function update_stats_charts(){
         responseTimeChart.chart.setOption({
             xAxis: {data: stats_history["time"]},
             series: [
-                {data: stats_history["response_time_percentile_50"], markLine: createMarkLine()},
-                {data: stats_history["response_time_percentile_95"]},
+                {data: stats_history["response_time_percentile_1"], markLine: createMarkLine()},
+                {data: stats_history["response_time_percentile_2"]},
             ]
         });
 
@@ -235,7 +235,7 @@ function update_stats_charts(){
 
 // init charts
 var rpsChart = new LocustLineChart($(".charts-container"), "Total Requests per Second", ["RPS", "Failures/s"], "reqs/s", ['#00ca5a', '#ff6d6d']);
-var responseTimeChart = new LocustLineChart($(".charts-container"), "Response Times (ms)", ["Median Response Time", "95% percentile"], "ms");
+var responseTimeChart = new LocustLineChart($(".charts-container"), "Response Times (ms)", [(percentile1 * 100).toString() + "th percentile" , (percentile2 * 100).toString() + "th percentile"], "ms");
 var usersChart = new LocustLineChart($(".charts-container"), "Number of Users", ["Users"], "users");
 charts.push(rpsChart, responseTimeChart, usersChart);
 echarts.connect([rpsChart.chart,responseTimeChart.chart,usersChart.chart])
@@ -264,8 +264,8 @@ function updateStats() {
                     stats_history["user_count"].push({"value": null});
                     stats_history["current_rps"].push({"value": null});
                     stats_history["current_fail_per_sec"].push({"value": null});
-                    stats_history["response_time_percentile_50"].push({"value": null});
-                    stats_history["response_time_percentile_95"].push({"value": null});
+                    stats_history["response_time_percentile_1"].push({"value": null});
+                    stats_history["response_time_percentile_2"].push({"value": null});
                 }
 
                 // update stats chart to ensure the stop spacing appears as part 
@@ -301,8 +301,8 @@ function updateStats() {
             stats_history["user_count"].push({"value": report.user_count});
             stats_history["current_rps"].push({"value": total.current_rps, "users": report.user_count});
             stats_history["current_fail_per_sec"].push({"value": total.current_fail_per_sec, "users": report.user_count});
-            stats_history["response_time_percentile_50"].push({"value": report.current_response_time_percentile_50, "users": report.user_count});
-            stats_history["response_time_percentile_95"].push({"value": report.current_response_time_percentile_95, "users": report.user_count});
+            stats_history["response_time_percentile_1"].push({"value": report.current_response_time_percentile_1, "users": report.user_count});
+            stats_history["response_time_percentile_2"].push({"value": report.current_response_time_percentile_2, "users": report.user_count});
             update_stats_charts();
 
         } catch(i){

locust/stats.py

@@ -133,6 +133,8 @@ def resize_handler(signum: int, frame: Optional[FrameType]):
 
 PERCENTILES_TO_REPORT = [0.50, 0.66, 0.75, 0.80, 0.90, 0.95, 0.98, 0.99, 0.999, 0.9999, 1.0]
 
+PERCENTILES_TO_CHART = [0.50, 0.95]
+
 
 class RequestStatsAdditionError(Exception):
     pass
@@ -888,8 +890,10 @@ def stats_history(runner: "Runner") -> None:
                 "time": datetime.datetime.now(tz=datetime.timezone.utc).strftime("%H:%M:%S"),
                 "current_rps": stats.total.current_rps or 0,
                 "current_fail_per_sec": stats.total.current_fail_per_sec or 0,
-                "response_time_percentile_95": stats.total.get_current_response_time_percentile(0.95) or 0,
-                "response_time_percentile_50": stats.total.get_current_response_time_percentile(0.5) or 0,
+                "response_time_percentile_1": stats.total.get_current_response_time_percentile(PERCENTILES_TO_CHART[0])
+                or 0,
+                "response_time_percentile_2": stats.total.get_current_response_time_percentile(PERCENTILES_TO_CHART[1])
+                or 0,
                 "user_count": runner.user_count or 0,
             }
             stats.history.append(r)

locust/templates/index.html

@@ -357,6 +357,8 @@ <h2>Version <a href="https://github.com/locustio/locust/releases/tag/{{version}}
         ]]>
     </script>
     <script type="text/javascript">
+        var percentile1 = {{ percentile1|tojson }};
+        var percentile2 = {{ percentile2|tojson }};
         {% include 'stats_data.html' %}
     </script>
     <script type="text/javascript" src="./static/chart.js?v={{ version }}"></script>

locust/templates/report.html

@@ -198,8 +198,10 @@ <h2>Final ratio</h2>
 
     <script>
         {% include 'stats_data.html' %}
+        var percentile1 = {{ percentile1|tojson }}
+        var percentile2 = {{ percentile2|tojson }}
         var rpsChart = new LocustLineChart($(".charts-container"), "Total Requests per Second", ["RPS", "Failures/s"], "reqs/s", ['#00ca5a', '#ff6d6d']);
-        var responseTimeChart = new LocustLineChart($(".charts-container"), "Response Times (ms)", ["Median Response Time", "95% percentile"], "ms");
+        var responseTimeChart = new LocustLineChart($(".charts-container"), "Response Times (ms)", [(percentile1*100).toString() + "th percentile" , (percentile2*100).toString() + "th percentile"], "ms");
         var usersChart = new LocustLineChart($(".charts-container"), "Number of Users", ["Users"], "users");
 
         if(stats_history["time"].length > 0){
@@ -214,8 +216,8 @@ <h2>Final ratio</h2>
             responseTimeChart.chart.setOption({
                 xAxis: {data: stats_history["time"]},
                 series: [
-                    {data: stats_history["response_time_percentile_50"]},
-                    {data: stats_history["response_time_percentile_95"]},
+                    {data: stats_history["response_time_percentile_1"]},
+                    {data: stats_history["response_time_percentile_2"]},
                 ]
             });
 

locust/templates/stats_data.html

@@ -1,10 +1,10 @@
-{% set time_data = [] %}{% set user_count_data = [] %}{% set current_rps_data = [] %}{% set current_fail_per_sec_data = [] %}{% set response_time_percentile_50_data = [] %}{% set response_time_percentile_95_data = [] %}{% for r in history %}{% do time_data.append(r.time) %}{% do user_count_data.append({"value": r.user_count}) %}{% do current_rps_data.append({"value": r.current_rps, "users": r.user_count}) %}{% do current_fail_per_sec_data.append({"value": r.current_fail_per_sec, "users": r.user_count}) %}{% do response_time_percentile_50_data.append({"value": r.response_time_percentile_50, "users": r.user_count}) %}{% do response_time_percentile_95_data.append({"value": r.response_time_percentile_95, "users": r.user_count}) %}{% endfor %}
+{% set time_data = [] %}{% set user_count_data = [] %}{% set current_rps_data = [] %}{% set current_fail_per_sec_data = [] %}{% set response_time_percentile_2_data = [] %}{% set response_time_percentile_1_data = [] %}{% for r in history %}{% do time_data.append(r.time) %}{% do user_count_data.append({"value": r.user_count}) %}{% do current_rps_data.append({"value": r.current_rps, "users": r.user_count}) %}{% do current_fail_per_sec_data.append({"value": r.current_fail_per_sec, "users": r.user_count}) %}{% do response_time_percentile_2_data.append({"value": r.response_time_percentile_2, "users": r.user_count}) %}{% do response_time_percentile_1_data.append({"value": r.response_time_percentile_1, "users": r.user_count}) %}{% endfor %}
 var stats_history = {
     "time": {{ time_data | tojson }}.map(server_time => new Date(new Date().setUTCHours(...(server_time.split(":")))).toLocaleTimeString()),
     "user_count": {{ user_count_data | tojson }},
     "current_rps": {{ current_rps_data | tojson }},
     "current_fail_per_sec": {{ current_fail_per_sec_data | tojson }},
-    "response_time_percentile_50": {{ response_time_percentile_50_data | tojson }},
-    "response_time_percentile_95": {{ response_time_percentile_95_data | tojson }},
+    "response_time_percentile_1": {{ response_time_percentile_1_data | tojson }},
+    "response_time_percentile_2": {{ response_time_percentile_2_data | tojson }},
     "markers": [],
 };

locust/test/test_main.py

@@ -1,6 +1,7 @@
 import json
 import os
 import platform
+
 import pty
 import signal
 import subprocess
@@ -191,6 +192,54 @@ def my_task(self):
             self.assertIn("Shutting down (exit code 0)", stderr)
             self.assertEqual(0, proc.returncode)
 
+    def test_percentile_parameter(self):
+        port = get_free_tcp_port()
+        with temporary_file(
+            content=textwrap.dedent(
+                """
+            from locust import User, task, constant, events
+            from locust.stats import PERCENTILES_TO_CHART
+            PERCENTILES_TO_CHART[0] = 0.9
+            PERCENTILES_TO_CHART[1] = 0.4
+            class TestUser(User):
+                wait_time = constant(3)
+                @task
+                def my_task(self):
+                    print("running my_task()")
+        """
+            )
+        ) as file_path:
+            proc = subprocess.Popen(
+                ["locust", "-f", file_path, "--web-port", str(port), "--autostart"], stdout=PIPE, stderr=PIPE, text=True
+            )
+            gevent.sleep(1)
+            response = requests.get(f"http://localhost:{port}/")
+            self.assertEqual(200, response.status_code)
+            proc.send_signal(signal.SIGTERM)
+            stdout, stderr = proc.communicate()
+            self.assertIn("Starting web interface at", stderr)
+
+    def test_invalid_percentile_parameter(self):
+        with temporary_file(
+            content=textwrap.dedent(
+                """
+            from locust import User, task, constant, events
+            from locust.stats import PERCENTILES_TO_CHART
+            PERCENTILES_TO_CHART[0] = 1.2
+            class TestUser(User):
+                wait_time = constant(3)
+                @task
+                def my_task(self):
+                    print("running my_task()")
+        """
+            )
+        ) as file_path:
+            proc = subprocess.Popen(["locust", "-f", file_path, "--autostart"], stdout=PIPE, stderr=PIPE, text=True)
+            gevent.sleep(1)
+            stdout, stderr = proc.communicate()
+            self.assertIn("parameter need to be float and value between. 0 < percentile < 1 Eg 0.95", stderr)
+            self.assertEqual(1, proc.returncode)
+
     def test_webserver_multiple_locustfiles(self):
         with mock_locustfile(content=MOCK_LOCUSTFILE_CONTENT_A) as mocked1:
             with mock_locustfile(content=MOCK_LOCUSTFILE_CONTENT_B) as mocked2:

locust/web.py

@@ -3,6 +3,7 @@
 import logging
 import os.path
 from functools import wraps
+
 from html import escape
 from io import StringIO
 from json import dumps
@@ -339,8 +340,8 @@ def request_stats() -> Response:
                     "errors": errors,
                     "total_rps": 0.0,
                     "fail_ratio": 0.0,
-                    "current_response_time_percentile_95": None,
-                    "current_response_time_percentile_50": None,
+                    "current_response_time_percentile_1": None,
+                    "current_response_time_percentile_2": None,
                     "state": STATE_MISSING,
                     "user_count": 0,
                 }
@@ -388,11 +389,15 @@ def request_stats() -> Response:
                 report["total_rps"] = stats[len(stats) - 1]["current_rps"]
                 report["fail_ratio"] = environment.runner.stats.total.fail_ratio
                 report[
-                    "current_response_time_percentile_95"
-                ] = environment.runner.stats.total.get_current_response_time_percentile(0.95)
+                    "current_response_time_percentile_1"
+                ] = environment.runner.stats.total.get_current_response_time_percentile(
+                    stats_module.PERCENTILES_TO_CHART[0]
+                )
                 report[
-                    "current_response_time_percentile_50"
-                ] = environment.runner.stats.total.get_current_response_time_percentile(0.5)
+                    "current_response_time_percentile_2"
+                ] = environment.runner.stats.total.get_current_response_time_percentile(
+                    stats_module.PERCENTILES_TO_CHART[1]
+                )
 
             if isinstance(environment.runner, MasterRunner):
                 workers = []
@@ -555,6 +560,8 @@ def update_template_args(self):
             "show_userclass_picker": self.userclass_picker_is_active,
             "available_user_classes": available_user_classes,
             "available_shape_classes": available_shape_classes,
+            "percentile1": stats_module.PERCENTILES_TO_CHART[0],
+            "percentile2": stats_module.PERCENTILES_TO_CHART[1],
         }
 
     def _update_shape_class(self, shape_class_name):