[NEW] benchmarks/py-locust: Python utility for doing distributed load tests

  Locust is an easy-to-use, distributed, user load testing tool. It is
  intended for load-testing web sites (or other systems) and figuring out
  how many concurrent users a system can handle.

  The behavior of each locust (or test user if you will) is defined by you
  and the swarming process is monitored from a web UI in real-time. This
  will help you battle test and identify bottlenecks in your code before
  letting real users in.

  WWW: https://locust.io/

Approved by:	araujo (mentor), rene (mentor)
Sponsored by:	cleverbridge AG
Differential Revision:	https://reviews.freebsd.org/D18895

1 files changed, 69 insertions, 0 deletions

diff --git a/benchmarks/py-locust/files/extra-EXAMPLES-events.py b/benchmarks/py-locust/files/extra-EXAMPLES-events.py
new file mode 100644
index 000000000000..7b1de7fafee2
--- /dev/null
+++ b/benchmarks/py-locust/files/extra-EXAMPLES-events.py
@@ -0,0 +1,69 @@
+# -*- coding: utf-8 -*-
+
+"""
+This is an example of a locustfile that uses Locust's built in event hooks to 
+track the sum of the content-length header in all successful HTTP responses
+"""
+
+from locust import HttpLocust, TaskSet, events, task, web
+
+
+class MyTaskSet(TaskSet):
+    @task(2)
+    def index(l):
+        l.client.get("/")
+    
+    @task(1)
+    def stats(l):
+        l.client.get("/stats/requests")
+
+class WebsiteUser(HttpLocust):
+    host = "http://127.0.0.1:8089"
+    min_wait = 2000
+    max_wait = 5000
+    task_set = MyTaskSet
+    
+
+"""
+We need somewhere to store the stats.
+
+On the master node stats will contain the aggregated sum of all content-lengths,
+while on the slave nodes this will be the sum of the content-lengths since the 
+last stats report was sent to the master
+"""
+stats = {"content-length":0}
+
+def on_request_success(request_type, name, response_time, response_length):
+    """
+    Event handler that get triggered on every successful request
+    """
+    stats["content-length"] += response_length
+
+def on_report_to_master(client_id, data):
+    """
+    This event is triggered on the slave instances every time a stats report is
+    to be sent to the locust master. It will allow us to add our extra content-length
+    data to the dict that is being sent, and then we clear the local stats in the slave.
+    """
+    data["content-length"] = stats["content-length"]
+    stats["content-length"] = 0
+
+def on_slave_report(client_id, data):
+    """
+    This event is triggered on the master instance when a new stats report arrives
+    from a slave. Here we just add the content-length to the master's aggregated
+    stats dict.
+    """
+    stats["content-length"] += data["content-length"]
+
+# Hook up the event listeners
+events.request_success += on_request_success
+events.report_to_master += on_report_to_master
+events.slave_report += on_slave_report
+
+@web.app.route("/content-length")
+def total_content_length():
+    """
+    Add a route to the Locust web app, where we can see the total content-length
+    """
+    return "Total content-length recieved: %i" % stats["content-length"]