[zeromq-dev] Client broken but the tcp connection still ESTABLISHED

[Michel Pelletier]

The connection is still established because that's the state the connection
was in when you terminated the client abruptly by powering it off, how is
the server supposed to know it went away?

There are several answers on stackoverflow that explain this.  I would also
suggest reading "Internetworking with TCP/IP" by Douglas E Comer.  You can
get older used editions for a couple of dollars on amazon.  You should have
a firm understanding of how networking works in order to write distributed
applications.

-Michel


On Thu, Jul 31, 2014 at 2:09 AM, 陈远 <jreader at 126.com> wrote:

> We use the zmq Req/Rep in our lan,we found a  mysterious thing:
> while the client machine broken(such as power off),
> the server side  shows the connection is still ESTABLISHED.
> See the list below ,the machie 192.168.6.72 had broken but the tcp
> connection still ESTABLISHED
>
> C:\Users\Administrator>netstat -an |findstr "1842"
>   TCP    0.0.0.0:1842           0.0.0.0:0              LISTENING
>   TCP    192.168.1.190:1842     192.168.6.72:16715     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:16729     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:19307     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:19309     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:20688     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:20691     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:56449     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.72:56451     ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.95:1318      ESTABLISHED
>   TCP    192.168.1.190:1842     192.168.6.95:1325      ESTABLISHED
>
>   Please help ?thank you!
>
>
>
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