I am using Bottle framework implementing the WSGI Request and response and because of the single thread issue, I changed the server into PythonWSGIServer and tested with Apache bench but the result consist of error broken pipe which is similar with this question How to prevent errno 32 broken pipe?. I have tried the answer but to no avail.
  Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/paste/httpserver.py", line 1068, in process_request_in_thread
    self.finish_request(request, client_address)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/SocketServer.py", line 323, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/SocketServer.py", line 641, in __init__
    self.finish()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/SocketServer.py", line 694, in finish
    self.wfile.flush()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/socket.py", line 303, in flush
    self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 32] Broken pipe
The server code is shown below, and I have no idea how to improve the connection, using thread pool?
from paste import httpserver
    @route('/')
    def index():
        connection = pymongo.MongoClient(connectionString)
        db = connection.test
        collection = db.test
        return str(collection.find_one())
    application = default_app()
    httpserver.serve(application, host='127.0.0.1', port=8082)