[X2go-dev] remote proxy closed the connection

[Gerry Reno]

On 02/04/2011 04:43 PM, Mike Gabriel wrote:
> Hi Gerry,
>
> On Fr 04 Feb 2011 22:14:28 CET Gerry Reno wrote:
>
>> Has anyone found out how to prevent this "remote proxy closed the
>> connection" error from happening when a session becomes detached and a
>> user tries to resume the session?
>>
>> We are seeing this problem quite often and every once in a while you can
>> get it to resume but mostly this session is unrecoverable and must be
>> manually terminated - which is creating much sysadmin work.
>
> Test the following:
>
> Whenever this error occurs, restart your X2go server's SSH daemon. My
> guess is that you can resume the session once SSH is restarted.
>
> I have read about weird port forwarding habits of the SSH daemon... I
> also meet these problems with PyHoca-GUI.
>
> Greets,
> Mike
>

Ok, the plot thickens.

I took a look at netstat both prior-to and after we get this error:

# normal state
# we can successfully resume a session

    # netstat -a | grep 300
    tcp        0      0 localhost:30008         *:*                    
    LISTEN    
    tcp        0      0 localhost:30009         *:*                    
    LISTEN    
    tcp6       0      0 ip6-localhost:30008     [::]:*                 
    LISTEN    
    tcp6       0      0 ip6-localhost:30009     [::]:*                 
    LISTEN    


# # after I forced a session to detach

    # netstat -a | grep 300
    tcp        0      0 localhost:30008         *:*                    
    LISTEN    
    tcp        0      0 localhost:30009         *:*                    
    LISTEN    
    tcp        0      0 localhost:33552         localhost:30037        
    TIME_WAIT 
    tcp6       0      0 ip6-localhost:30008     [::]:*                 
    LISTEN    
    tcp6       0      0 ip6-localhost:30009     [::]:*                 
    LISTEN    


# # if we just wait for a while then reattempt to resume the session it
succeeds

    # netstat -a | grep 300
    tcp        0      0 localhost:30008         *:*                    
    LISTEN    
    tcp        0      0 localhost:30009         *:*                    
    LISTEN    
    tcp6       0      0 ip6-localhost:30008     [::]:*                 
    LISTEN    
    tcp6       0      0 ip6-localhost:30009     [::]:*                 
    LISTEN    


So whatever is causing this TIME_WAIT is what appears to have a role in
the error.


Regards,
Gerry