Tor Erik wrote: > Fredrik Lundh wrote: >> Tor Erik wrote: >> >>> The reason is that my application does about 16 connects and data >>> transfers per second, to the same 16 remote hosts. After approx 200 >>> secs there are 4000 sockets waiting to be garbage collected by the OS. >> >> what does "netstat" say about these sockets ? >> >> </F> >> > > They are in the TIME_WAIT state... The msn library has an article on how > to solve this: > > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/BTS06CoreDocs/html/6987640c-1d80-4fbf-b43a-021fc8ba06a4.asp > > > > Summing up one could either: > > 1. Increase the upper range of ephemeral ports that are dynamically > allocated to client TCP/IP socket connections: > > set registry key: > KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\MaxUserPort > > > to a new DWORD value... (5000 - 65534) > The default in XP is 3976 -> http://support.microsoft.com/kb/Q149532 > > or > > 2. Reduce the client TCP/IP socket connection timeout value from the > default value of 240 seconds > > set registry key: > HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpTimedWaitDelay > > > to a new DWORD value (30 - 300) > > The TCP RFC (RFC 793) recommends a value of 2*msl(Maximum Segment > Lifetime). The general consensus about the value of msn seems to be 1-2 > minutes, depending on the underlying network... (2*2 min = 2*120 sec = > 240 sec) > > > I do not want to alter my registry, so I'm currently testing an idea > where I let the client connect and send its content, appended with my > own "magic" EOF byte-sequence. When the server receives this EOF, it > takes care to close the connection. This should eliminate the problem as > it is the peer closing the connection that enters the TIME_WAIT state... > > I will report my experiences...
Well... my idea does not work as expected. Even though the server (remote host) calls socket.close(), it is the client that executes TIME_WAIT. My guess is that the subtrates below socket closes the connection at the peer calling connect regardless of where socket.close is called. Thoughts anyone? -- http://mail.python.org/mailman/listinfo/python-list
