Added logic the the http server to keep it from accepting new connections when...

Added logic the the http server to keep it from accepting new connections when the server is over loaded. This should keep the server from breaking by doing a select with too many descriptors, and should also help keep the server from running out of descriptors.

ZServer/HTTPServer.py

@@ -117,7 +117,7 @@ from HTTPResponse import make_response
 from ZPublisher.HTTPRequest import HTTPRequest
 
 from medusa.http_server import http_server, http_channel
-from medusa import counter, producers, asyncore
+from medusa import counter, producers, asyncore, max_sockets
 from medusa.default_handler import split_path, unquote, get_header
 
 CONTENT_LENGTH = regex.compile('Content-Length: \([0-9]+\)',regex.casefold)
@@ -337,5 +337,12 @@ class zhttp_server(http_server):
     "http server"
     
     SERVER_IDENT='Zope/%s ZServer/%s' % (ZOPE_VERSION,ZSERVER_VERSION)
+    CONNECTION_LIMIT=max_sockets.max_select_sockets()
     
     channel_class = zhttp_channel
+
+    def handle_accept(self):
+        if len(asyncore.socket_map.keys()) >= self.CONNECTION_LIMIT:
+	    return
+        http_server.handle_accept(self)
+

ZServer/medusa/max_sockets.py

+# -*- Mode: Python; tab-width: 4 -*-
+
+import socket
+import select
+
+# several factors here we might want to test:
+# 1) max we can create
+# 2) max we can bind
+# 3) max we can listen on
+# 4) max we can connect
+
+def max_server_sockets():
+	sl = []
+	while 1:
+		try:
+			s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+			s.bind (('',0))
+			s.listen(5)
+			sl.append (s)
+		except:
+			break
+	num = len(sl) - 1
+	for s in sl:
+		s.close()
+	del sl
+	return num
+
+def max_client_sockets():
+	# make a server socket
+	server = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+	server.bind (('', 9999))
+	server.listen (5)
+	sl = []
+	while 1:
+		try:
+			s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+			s.connect (('', 9999))
+			conn, addr = server.accept()
+			sl.append ((s,conn))
+		except:
+			break
+	num = len(sl) - 1
+	for s,c in sl:
+		s.close()
+		c.close()
+	del sl
+	return num
+
+def max_select_sockets():
+	sl = []
+	while 1:
+		try:
+			s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+			s.bind (('',0))
+			s.listen(5)
+			sl.append (s)
+			select.select(sl,[],[],0)
+		except:
+			break
+	num = len(sl) - 1
+	for s in sl:
+		s.close()
+	del sl
+	return num
+	
+	
+

lib/python/ZServer/HTTPServer.py

@@ -117,7 +117,7 @@ from HTTPResponse import make_response
 from ZPublisher.HTTPRequest import HTTPRequest
 
 from medusa.http_server import http_server, http_channel
-from medusa import counter, producers, asyncore
+from medusa import counter, producers, asyncore, max_sockets
 from medusa.default_handler import split_path, unquote, get_header
 
 CONTENT_LENGTH = regex.compile('Content-Length: \([0-9]+\)',regex.casefold)
@@ -337,5 +337,12 @@ class zhttp_server(http_server):
     "http server"
     
     SERVER_IDENT='Zope/%s ZServer/%s' % (ZOPE_VERSION,ZSERVER_VERSION)
+    CONNECTION_LIMIT=max_sockets.max_select_sockets()
     
     channel_class = zhttp_channel
+
+    def handle_accept(self):
+        if len(asyncore.socket_map.keys()) >= self.CONNECTION_LIMIT:
+	    return
+        http_server.handle_accept(self)
+

lib/python/ZServer/medusa/max_sockets.py

+# -*- Mode: Python; tab-width: 4 -*-
+
+import socket
+import select
+
+# several factors here we might want to test:
+# 1) max we can create
+# 2) max we can bind
+# 3) max we can listen on
+# 4) max we can connect
+
+def max_server_sockets():
+	sl = []
+	while 1:
+		try:
+			s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+			s.bind (('',0))
+			s.listen(5)
+			sl.append (s)
+		except:
+			break
+	num = len(sl) - 1
+	for s in sl:
+		s.close()
+	del sl
+	return num
+
+def max_client_sockets():
+	# make a server socket
+	server = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+	server.bind (('', 9999))
+	server.listen (5)
+	sl = []
+	while 1:
+		try:
+			s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+			s.connect (('', 9999))
+			conn, addr = server.accept()
+			sl.append ((s,conn))
+		except:
+			break
+	num = len(sl) - 1
+	for s,c in sl:
+		s.close()
+		c.close()
+	del sl
+	return num
+
+def max_select_sockets():
+	sl = []
+	while 1:
+		try:
+			s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
+			s.bind (('',0))
+			s.listen(5)
+			sl.append (s)
+			select.select(sl,[],[],0)
+		except:
+			break
+	num = len(sl) - 1
+	for s in sl:
+		s.close()
+	del sl
+	return num
+	
+	
+