meinheld 1.0.2
High performance asynchronous Python WSGI Web Server
License: BSD

What's this
---------------------------------

.. image:: https://travis-ci.org/mopemope/meinheld.svg
    :target: https://travis-ci.org/mopemope/meinheld

This is a high performance python wsgi web server.

And Meinheld is a WSGI compliant web server. (PEP333 and PEP3333 supported)

You can also join us in `meinheld mailing list`_.

Requirements
---------------------------------

Meinheld requires **Python 2.x >= 2.6** or **Python 3.x >= 3.5** . and **greenlet >= 0.4.5**.

Meinheld supports Linux, FreeBSD, and macOS.

Installation
---------------------------------

Install from pypi::

  $ pip install -U meinheld

Install from source::

  $ python setup.py install

Meinheld also supports working as a gunicorn worker.

To install gunicorn::

  $ pip install -U gunicorn


Basic Usage
---------------------------------

simple wsgi app:

.. code:: python

    from meinheld import server

    def hello_world(environ, start_response):
        status = b'200 OK'
        res = b"Hello world!"
        response_headers = [('Content-type', 'text/plain'), ('Content-Length', str(len(res)))]
        start_response(status, response_headers)
        return [res]

    server.listen(("0.0.0.0", 8000))
    server.run(hello_world)


with gunicorn. user worker class "egg:meinheld#gunicorn_worker" or "meinheld.gmeinheld.MeinheldWorker"::

    $ gunicorn --workers=2 --worker-class="egg:meinheld#gunicorn_worker" gunicorn_test:app

Continuation
---------------------------------

**NOTE: This feature is deprecated and will be removed in 2.0**

Meinheld provides a simple continuation API (based on greenlet).

To enable continuations, use ContinuationMiddleware. get Continuation from wsgi environ.

Continuation objects have two very interesting methods, `suspend` and `resume`.

For example:

.. code:: python

    from meinheld import server
    from meinheld import middleware

    def app(environ, start_response):
        ...

        #get Continuation
        c = environ.get(middleware.CONTINUATION_KEY, None)

        ...

        if condtion:
            waiters.append(c)
            #suspend
            c.suspend()
        else:
            for c in waiters:
                # resume suspend function
                c.resume()

        ...


    server.listen(("0.0.0.0", 8000))
    server.run(middleware.ContinuationMiddleware(hello_world))

For more info see http://github.com/mopemope/meinheld/tree/master/example/chat/

Websocket
---------------------------------

**NOTE: This feature is deprecated and will be removed in 2.0**

Meinheld support Websockets. use WebSocketMiddleware.

For example:

.. code:: python

    from flask import Flask, render_template, request
    from meinheld import server, middleware

    SECRET_KEY = 'development key'
    DEBUG=True

    app = Flask(__name__)
    app.config.from_object(__name__)


    participants = set()


    @app.route('/')
    def index():
        return render_template('websocket_chat.html')

    @app.route('/chat')
    def chat():
        print request.environ
        ws = request.environ.get('wsgi.websocket')
        participants.add(ws)
        try:
            while True:
                print "ws.wait()..."
                m = ws.wait()
                print "recv msg %s" % m
                if m is None:
                    break
                for p in participants:
                    print "send message %s" % m
                    p.send(m)
        finally:
            participants.remove(ws)
        return ""


    if __name__ == "__main__":
        server.listen(("0.0.0.0", 8000))
        server.run(middleware.WebSocketMiddleware(app))


Patching
---------------------------------

**NOTE: This feature is deprecated and will be removed in 2.0**

Meinheld provides a few monkeypatches.

Socket
==========================================

This patch replaces the standard socket module.

For Example:

.. code:: python

    from meinheld import patch
    patch.patch_all()

For more info see http://github.com/mopemope/meinheld/tree/master/example/patch/


Performance
------------------------------

For parsing HTTP requests, Meinheld uses Ryan Dahl's http-parser library.

(see https://github.com/joyent/http-parser)

It is built around the high performance event library picoev.

(see http://developer.cybozu.co.jp/kazuho/2009/08/picoev-a-tiny-e.html)

Sendfile
===========================

Meinheld uses sendfile(2), over wgsi.file_wrapper.

.. _meinheld mailing list: http://groups.google.com/group/meinheld