[X2go-dev] remote proxy closed the connection
Gerry Reno
greno at verizon.net
Sat Feb 5 02:31:53 CET 2011
On 02/04/2011 06:09 PM, Gerry Reno wrote:
> On 02/04/2011 06:01 PM, Gerry Reno wrote:
>
>> 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
>>
>>
>>
>>
>>
> What's interesting is that it presents the menu and the process is shown
> as "running" so then your "suspend" it and "resume" it and you still get
> the "remote proxy closed the connection" error and NX proxy shows
> "aborting" but it does resume the session. Very confusing to users but
> at least they get their session back.
>
>
> Regards,
> Gerry
>
>
The TIME_WAIT occurs on the server because apparently there is no
keep_alive which would make the client responsible for closing the
connection. I didn't see any TCPKeepAlive=yes in the ssh options which
may be accounting for TIME_WAIT showing up on the server.
Regards,
Gerry
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