best effort to handle auto-reconnection transparently PYTHON-108

Author: Mike Dirolf

pymongo/connection.py

@@ -35,9 +35,11 @@
 
 import datetime
 import os
+import select
 import socket
 import struct
 import threading
+import time
 import warnings
 
 from pymongo import (database,
@@ -113,6 +115,16 @@ def _parse_uri(uri, default_port):
  return (host_list, database, username, password)
 
 
+def _closed(sock):
+ """Return True if we know socket has been closed, False otherwise.
+ """
+ rd, _, _ = select.select([sock], [], [], 0)
+ try:
+ return len(rd) and sock.recv() == ""
+ except:
+ return True
+
+
 class _Pool(threading.local):
  """A simple connection pool.
 
@@ -280,6 +292,7 @@ def __init__(self, host=None, port=None, pool_size=None,
  self.__cursor_manager = CursorManager(self)
 
  self.__pool = _Pool(self.__connect)
+ self.__last_checkout = time.time()
 
  self.__network_timeout = network_timeout
  self.__document_class = document_class
@@ -515,6 +528,26 @@ def __connect(self):
  self.disconnect()
  raise AutoReconnect("could not connect to %r" % list(self.__nodes))
 
+ def __socket(self):
+ """Get a socket from the pool.
+
+ If it's been > 1 second since the last time we checked out a
+ socket, we also check to see if the socket has been closed -
+ this let's us avoid seeing *some*
+ :class:`~pymongo.errors.AutoReconnect` exceptions on server
+ hiccups, etc. We only do this if it's been > 1 second since
+ the last socket checkout, to keep performance reasonable - we
+ can't avoid those completely anyway.
+ """
+ sock = self.__pool.socket()
+ t = time.time()
+ if t - self.__last_checkout > 1:
+ if _closed(sock):
+ self.disconnect()
+ sock = self.__pool.socket()
+ self.__last_checkout = t
+ return sock
+
  def disconnect(self):
  """Disconnect from MongoDB.
 
@@ -595,7 +628,7 @@ def _send_message(self, message, with_last_error=False):
  - `with_last_error`: check getLastError status after sending the
  message
  """
- sock = self.__pool.socket()
+ sock = self.__socket()
  try:
  (request_id, data) = message
  sock.sendall(data)
@@ -658,7 +691,7 @@ def _send_message_with_response(self, message,
  :Parameters:
  - `message`: (request_id, data) pair making up the message to send
  """
- sock = self.__pool.socket()
+ sock = self.__socket()
 
  try:
  try: