wsgi-statsd 0.2.2

WSGI middleware for statsd timing

wsgi-statsd documentation

wsgi_statsd is a WSGI middleware that provides an easy way to time all requests. Integration is as easy as just wrapping your existing wsgi application.

Contents

• wsgi-statsd documentation

  • Usage

  • What it does

  • Customizing for your needs

  • Contact

  • License

• Changelog

  • 0.2.2

  • 0.2.1

  • 0.2.0

  • 0.1.0

Usage

In your wsgi.py file wrap your WSGI application as follows:

import statsd
from wsgi_statsd import StatsdTimingMiddleware


def application(environ, start_response):
    response_body = 'The request method was %s' % environ['REQUEST_METHOD']
    status = '200 OK'
    response_headers = [('Content-Type', 'text/plain'),
                        ('Content-Length', str(len(response_body)))]

    start_response(status, response_headers)

    return [response_body]

client = statsd.StatsClient(
    prefix='your_prefix',
    host='your_host',
    port=8125
)

application = StatsdTimingMiddleware(application, client)

Note

If an unhandled exception happens, it will not be timed by default. This is the design decision to separate error reporting and actual statistical measurements. To enable exception timing, pass time_exception=True to the middleware constructor:

application = StatsdTimingMiddleware(application, client, time_exceptions=True)

What it does

The middleware uses the statsd timer function, using the environ[‘PATH_INFO’], environ[‘REQUEST_METHOD’] and the status code variables as the name for the key and the amount of time the request took as the value.

That’s it.

If you want more granular reporting you’ll have to work with the prefix argument. You can pass any string you want and the middleware will pass it along to statsd.

Using the foo prefix and calling the www.spam.com/bar page will result in foo.bar.GET.200 having a value equal to the time it took to handle the request.

If you passed time_exceptions=True and exception happened during the response, then the key name will be postfixed with the exception class name: foo.bar.GET.200.ValueError

Customizing for your needs

It’s possible to customize the way wsgi_statsd generates the key and/or time. StatsdTimingMiddleware has send_stats and get_key_name which you can override:

class CustomStatsdMiddleware(StatsdTimingMiddleware):

    def get_key_name(self, environ, response_interception):
        return super(self, CustomStatsdMiddleware).get_key_name(environ, response_interception) + '.' + environ['Transfer-Encoding']


    def send_stats(self, start, environ, response_interception):
        super(self, CustomStatsdMiddleware).send_stats(start + 10, environ, response_interception)

Contact

If you have questions, bug reports, suggestions, etc. please create an issue on the GitHub project page.

License

This software is licensed under the MIT license

Please refer to the license file

© 2015 Wouter Lansu, Paylogic International and others.

Changelog

0.2.2

• Add exception class name to the key when exception happens (bubenkoff)

0.2.1

• ensure close() is properly called from the response (bubenkoff, GrahamDumpleton)

• optionally time exceptions (bubenkoff)

• code readability improvements (bubenkoff)

0.2.0

• Fixed version numbers

• Added support for WSGI applications returning generators

• Added a test to verify that the response body remains the same after passing through the middleware

0.1.0

• Initial public release