in reply to Socket hang. (Windows or Perl? Solutions?) (Updated)

>perl -v
This is perl 5, version 12, subversion 3 (v5.12.3) built for MSWin32-x
+86-multi-thread
...
Binary build 1204 [294330] provided by ActiveState http://www.ActiveSt
+ate.com
...

>perl a.pl -port=12347
server:41930 client:41930 cycles: 597.742/secTerminating on signal SIG
+INT(2)

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This is where it first froze. I immediately ran the following: 

>netstat /a

Active Connections

  Proto  Local Address          Foreign Address        State
...
  TCP    127.0.0.1:12347        tribble:49157          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49159          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49161          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49162          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49163          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49164          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49165          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49166          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49167          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49168          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49169          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49170          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49171          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49172          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49173          TIME_WAIT
  TCP    127.0.0.1:12347        tribble:49174          TIME_WAIT
...

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I presume there are 41930 of those in total.

This would account for the pause. My question isn't why I get these in Windows. My question is why didn't linux show a similar pause. I'll see what netstat shows in linux tomorrow.

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Re^2: Socket hang. (Windows or Perl? Solutions?) (Updated)
by spx2 (Deacon) on Apr 06, 2011 at 08:52 UTC

    In Linux, in order to avoid running out of sockets you can use the following as root:

    echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle

    I'm not sure how your Linux install is set, just wanted to mention that I once wrote a bot to monitor svn commits and it had this problem and netstat would uncover many 

    TIME_WAIT
    still opened but unused connections.

    Here are some docs that describe what tcp_tw_recycle does(Taken from ip-sysctl.txt): 

    tcp_tw_recycle - BOOLEAN
	Enable fast recycling TIME-WAIT sockets. Default value is 0.
	It should not be changed without advice/request of technical
	experts.
[reply]

      In Linux, in order to avoid running out of sockets you can use the following as root:

      Backwards. I'm not running out of sockets in Debian, even though I'm creating sockets 3x faster than one Windows.

      /proc/sys/net/ipv4/tcp_tw_recycle contains a zero. netstat -a shows a bajillion sockets in TIME_WAIT.

      Why is it not running out of sockets?

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