Load Testing

Server Side

Legacy Tests - https://github.com/edx/load-tests (internal-only repo)

Current Tests - https://github.com/edx/edx-load-tests

Framework - https://github.com/locustio/locust(used currently in edx-load-tests. We also have a fork, and some legacy JMeter scripts)

How to Run Performance Tests

Client Side (Browser)

Framework - http://www.sitespeed.io/ (Install via npm)

Useful add-in - https://github.com/edx/edx-sitespeed (for logged-in sessions)

Network throttling tools: Network Link Conditioner, tc (ubuntu native), wondersharper (which does not work on virtual machines), etc

Monitoring in Environments

New Relic

https://rpm.newrelic.com/accounts/88178/browser/1588430

Profiling

PyInstrument

PyInstrument can be helpful because of the way it writes output data as a call tree. More info here:

https://github.com/joerick/pyinstrument

Example of a profile using pyinstrument, writing output to a file:

from pyinstrument import Profiler
profiler = Profiler(use_signal=False)
profiler.start()
# Do stuff here
profiler.stop()
 
# write profile data to file
with open('my.log', 'w') as f:
  f.write(profiler.output_text())

RunSnakeRun

Here are the steps to profile your python code with cProfile and then view the results using RunSnakeRun.

export VAGRANT_X11=1
vagrant ssh
First time only:
1. sudo pip install wxPython
2. sudo apt-get install python-profiler python-wxgtk2.8 python-setuptools
3. sudo pip install SquareMap RunSnakeRun
sudo su edxapp

Add the following to the code that you want to profile

Profiling block

import cProfile
import uuid
pr = cProfile.Profile()
pr.enable()
try:
    <python_code_to_profile>
finally:
    pr.disable()
    pr.dump_stats("<filepath>_{0}_<git_hash>.profile".format(uuid.uuid4()))

Then use RunSnake by issuing:
1. runsnake DIRECTORY/FILE_NAME.profile

Tips

When profiling locally, disable features that would affect performance numbers. For instance, the following can be set in the a local [lms/cms]/envs/private.py file:

from .common import INSTALLED_APPS, MIDDLEWARE_CLASSES, FEATURES
def tuple_without(source_tuple, exclusion_list):
    """Return new tuple excluding any entries in the exclusion list. Needed because tuples
    are immutable. Order preserved."""
    return tuple([i for i in source_tuple if i not in exclusion_list])
INSTALLED_APPS = tuple_without(INSTALLED_APPS, ['debug_toolbar', 'debug_toolbar_mongo'])
MIDDLEWARE_CLASSES = tuple_without(MIDDLEWARE_CLASSES, [
    'django_comment_client.utils.QueryCountDebugMiddleware',
    'debug_toolbar.middleware.DebugToolbarMiddleware',
])
DEBUG_TOOLBAR_MONGO_STACKTRACES = False

import contracts
contracts.disable_all()

Performance tools