Skip to main content
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [sumo-user] Address already in use: Race condition between isolated executions 
Hi,
yes it is the intended behavior. We noticed that there is no point in leaving the port open once all clients have connected. So we just close it and it is available to be used again. This should also help in avoiding conflicts since the ports are not open very long. 

Best regards,
Michael

Am 26.11.20 um 13:02 schrieb Marcelo Andrade Rodrigues D Almeida:

Sorry for the very late reply and thank you for working on it

I built it from the source and tested it with the simple example above
I was expecting it to leave an exception telling that the address was already in use, instead of hanging the process.
The behavior now is that the second connection is successful even though the same port was used.
When inspecting the system tcp ports with 'netstat -atn', it seems that both are created with a 'double-mapping' (port 50000) 

(base) marcelo@Lenovo-Legion-5-15IMH05H:~$ netstat -atn
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 0.0.0.0:34463 <http://0.0.0.0:34463> 0.0.0.0:*               LISTEN tcp        0      0 127.0.0.53:53 <http://127.0.0.53:53> 0.0.0.0:*               LISTEN tcp        0      0 127.0.0.1:631 <http://127.0.0.1:631> 0.0.0.0:*               LISTEN tcp        0      0 127.0.0.1:50000 <http://127.0.0.1:50000> 127.0.0.1:45794 <http://127.0.0.1:45794>         ESTABLISHED tcp        0      0 192.168.1.5:48216 <http://192.168.1.5:48216> 216.58.202.142:443 <http://216.58.202.142:443>      ESTABLISHED tcp        0      0 192.168.1.5:55908 <http://192.168.1.5:55908> 3.85.152.15:443 <http://3.85.152.15:443>         ESTABLISHED tcp        0      0 127.0.0.1:60188 <http://127.0.0.1:60188> 127.0.0.1:59996 <http://127.0.0.1:59996>         TIME_WAIT tcp        0      0 127.0.0.1:45794 <http://127.0.0.1:45794> 127.0.0.1:50000 <http://127.0.0.1:50000>         ESTABLISHED tcp        0      0 127.0.0.1:60192 <http://127.0.0.1:60192> 127.0.0.1:59996 <http://127.0.0.1:59996>         TIME_WAIT tcp        0      0 192.168.1.5:45396 <http://192.168.1.5:45396> 75.2.53.94:443 <http://75.2.53.94:443>          ESTABLISHED tcp        0      0 192.168.1.5:33528 <http://192.168.1.5:33528> 198.252.206.25:443 <http://198.252.206.25:443>      ESTABLISHED tcp        0      0 127.0.0.1:43994 <http://127.0.0.1:43994> 127.0.0.1:34859 <http://127.0.0.1:34859>         TIME_WAIT tcp        0      0 127.0.0.1:50000 <http://127.0.0.1:50000> 127.0.0.1:45798 <http://127.0.0.1:45798>         ESTABLISHED tcp        0      0 192.168.1.5:48220 <http://192.168.1.5:48220> 216.58.202.142:443 <http://216.58.202.142:443>      TIME_WAIT tcp        0      0 192.168.1.5:58644 <http://192.168.1.5:58644> 3.225.183.105:443 <http://3.225.183.105:443>       ESTABLISHED tcp        0      0 192.168.1.5:48502 <http://192.168.1.5:48502> 216.58.202.142:443 <http://216.58.202.142:443>      ESTABLISHED tcp        0      0 127.0.0.1:56510 <http://127.0.0.1:56510> 127.0.0.1:34165 <http://127.0.0.1:34165>         ESTABLISHED tcp        0      0 192.168.1.5:43464 <http://192.168.1.5:43464> 52.11.85.228:443 <http://52.11.85.228:443>        ESTABLISHED tcp        0      0 192.168.1.5:44560 <http://192.168.1.5:44560> 172.217.28.74:443 <http://172.217.28.74:443>       ESTABLISHED tcp        0      0 192.168.1.5:36802 <http://192.168.1.5:36802> 172.217.28.3:443 <http://172.217.28.3:443>        ESTABLISHED tcp        0      0 127.0.0.1:45798 <http://127.0.0.1:45798> 127.0.0.1:50000 <http://127.0.0.1:50000>         ESTABLISHED tcp        0      0 127.0.0.1:34118 <http://127.0.0.1:34118> 127.0.0.1:40919 <http://127.0.0.1:40919>         CLOSE_WAIT tcp        0      0 192.168.1.5:51196 <http://192.168.1.5:51196> 107.21.203.251:443 <http://107.21.203.251:443>      ESTABLISHED tcp        0      0 192.168.1.5:36070 <http://192.168.1.5:36070> 172.217.192.189:443 <http://172.217.192.189:443>     ESTABLISHED tcp        0      0 192.168.1.5:36662 <http://192.168.1.5:36662> 34.235.68.102:443 <http://34.235.68.102:443>       TIME_WAIT tcp        0      0 192.168.1.5:37930 <http://192.168.1.5:37930> 172.217.29.229:443 <http://172.217.29.229:443>      ESTABLISHED tcp6       0      0 127.0.0.1:6942 <http://127.0.0.1:6942>          :::*                    LISTEN tcp6       0      0 127.0.0.1:63342 <http://127.0.0.1:63342> :::*                    LISTEN 
tcp6       0      0 :::80                   :::*                    LISTEN
tcp6       0      0 :::34165                :::*                    LISTEN
tcp6       0      0 :::40919                :::*                    LISTEN
tcp6       0      0 ::1:631                 :::*                    LISTEN
tcp6       0      0 127.0.0.1:40919 <http://127.0.0.1:40919> 127.0.0.1:34118 <http://127.0.0.1:34118>         FIN_WAIT2 tcp6       0      0 127.0.0.1:34165 <http://127.0.0.1:34165> 127.0.0.1:56510 <http://127.0.0.1:56510>         ESTABLISHED 


Is this the intended behavior?


Thank you once again


Sincerely,

Marcelo d'Almeida
On Tue, Nov 3, 2020 at 6:10 PM Michael Behrisch <oss@xxxxxxxxxxx <mailto:oss@xxxxxxxxxxx>> wrote: 

    Hi,
    you are right, this behavior is not useful. I opened a ticket here:
    https://github.com/eclipse/sumo/issues/7750
    <https://github.com/eclipse/sumo/issues/7750>. It already has a
    preliminary fix but this needs a little more testing. If you like, you
    can try the nightly build (showing up tomorrow) or build yourself and
    report your findings.

    Best regards,
    Michael

    Am 03.11.20 um 18:08 schrieb Marcelo Andrade Rodrigues D Almeida:
     > Hi everyone
     >
     > Trying to open two simulations with the same port hangs the entire
     > execution, instead of raising an exception
     >
     > Error
     > "Error: tcpip::Socket::accept() Unable to create listening socket:
     > Address already in use
     > Quitting (on error)."
     >
     >
     > I'm currently running several experiments, simultaneously, in
    isolated
     > docker containers. And inside every experiment, running several
    parallel
     > simulations
     >
     > The problem is that my experiments can step (and eventually does)
    into
     > address conflict problems (race condition) and the hanging
    prevents any
     > chance of retrying it with a new port, suspending the entire
    experiment
     > forever.
     >
     > The use of synchronization locks prevents address conflicts
    inside one
     > experiment, so I'm basically limited to run one experiment at a time,
     > which is very time consuming.
     >
     >
     > As a workaround, I'm going to specify port ranges for each simulation
     > and check it for availability
     >
     > Let me know if there is a better solution as workaround
     >
     > And thank you in advance
     >
     >
     > P.S. I've included a trivial example to show the hanging
    behavior, but
     > there is nothing special about it.
     >
     >
     > Sincerely,
     >
     > Marcelo d'Almeida
     >
     > _______________________________________________
     > sumo-user mailing list
     > sumo-user@xxxxxxxxxxx <mailto:sumo-user@xxxxxxxxxxx>
     > To unsubscribe from this list, visit
    https://www.eclipse.org/mailman/listinfo/sumo-user
    <https://www.eclipse.org/mailman/listinfo/sumo-user>
     >


    _______________________________________________
    sumo-user mailing list
    sumo-user@xxxxxxxxxxx <mailto:sumo-user@xxxxxxxxxxx>
    To unsubscribe from this list, visit
    https://www.eclipse.org/mailman/listinfo/sumo-user
    <https://www.eclipse.org/mailman/listinfo/sumo-user>


_______________________________________________
sumo-user mailing list
sumo-user@xxxxxxxxxxx
To unsubscribe from this list, visit https://www.eclipse.org/mailman/listinfo/sumo-user

Back to the top