What's this
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:
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:
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:
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:
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.