[Xastir] Xastir 1.3.xx and wx200d problems

Wed Apr 28 20:21:56 EDT 2004

Here is an ethereal trace of what is happening between xastir and wx200d... 
looks like a socket is established, a few pakets are exchanged and then, 
after a while of inactivity, the socket is closed and immediately 
re-opened... but netstat shows the socket hanging in a CLOSE_WAIT state. This 
repeats on and on...

I am not a TCP expert by any means... can you tell me if the closure of the 
socket is correct or if there is anything missing?

Thanks,

--sam

On Wednesday 28 April 2004 12:39, Stefano Angelo Mario Lassini wrote:
> I agree with the analysis you make of this. I will have to wait until I
> get back home tonight to try ethereal and see what it tells me. I haven't
> used that tool in the past, but hopefully it is available in the Suse 9.0
> pro distro, in which case it will only take a minute to install it on my
> machine.
>
> I'll check and report what I find.
>
> Thanks,
>
> --sam
>
> > Sam,
> >
> > 	What I'm thinking is that one side or the other isn't fully closing.  I
> > was hoping that a trace from Ethereal would give some indication as to
> > where the TCP-CLOSE (FIN?) wasn't being completed.
> >
> > 			THX/BDH
> >
> > On Wed, 2004-04-28 at 10:14, Stefano Angelo Mario Lassini wrote:
> >> Brian,
> >>
> >> Thanks for the suggestion.
> >> I am able to ascertain that many sockets on the wx200d side are left in
> >> a
> >> CLOSE_WAIT state that causes them to hang forever (until the wx200d
> >> process is killed and restarted). This happens both with sockets opened
> >> from xastir and with sockets opened from the wx200 command line client
> >> for
> >> wx200d, so it seems to be a problem that goes beyond xastir.
> >>
> >> BTW, the connections are local, i.e. both xastir and the wx200d daemon
> >> are
> >> running on the same machine (I might migrate wx200d to another machine
> >> once I get this issue figured out).
> >>
> >> --sam
> >>
> >> > Sam,
> >> >
> >> > 	Do you have Ethereal on either of the Linux machines in question?  I
> >> > think you've got something not fully closing a socket.  If you can get
> >>
> >> a
> >>
> >> > trace of it you should be able to see what is being left hanging.
> >> >
> >> > 			THX/BDH
> >> >
> >> > On Mon, 2004-04-26 at 21:10, Stefano Angelo Mario Lassini wrote:
> >> >> Over the past few weeks I have experienced failures in my
> >>
> >> xastir/wx200d
> >>
> >> >> setup
> >> >> that would cause wx200d to stop responding after a couple of days or
> >> >> less of
> >> >> uptime. If xastir was not connected to the network wx port wx200d
> >>
> >> would
> >>
> >> >> run
> >> >> for many days at a time without problems.
> >> >>
> >> >> I eventually traced the symptoms to the fact that the number of open
> >> >> sockets
> >> >> to wx200d would increase to the point that several hundreds of socket
> >>
> >> at
> >>
> >> >> a
> >> >> time were open to wx200d (or so appears by listing /proc/{wx200d
> >> >> PID}/fd.
> >> >> Apparently every time that Xastir believes that the connectoin to
> >>
> >> wx200d
> >>
> >> >> is
> >> >> down (due to lack of wx200d activity) it attempts to re-connect and
> >>
> >> in
> >>
> >> >> the
> >> >> process a new socket is created and the old one is left hanging.
> >> >>
> >> >> Once the number of sockets grows beyond the number of file
> >>
> >> descriptors
> >>
> >> >> available to wx200d the daemon hangs, and needs to be killed and
> >> >> restarted.
> >> >>
> >> >> I have tried to look at the code responsible for the networked
> >>
> >> weather
> >>
> >> >> station, but I have to admit that my understanding of the structure
> >>
> >> of
> >>
> >> >> the
> >> >> xastir code base is pretty weak...
> >> >>
> >> >> Can anyone provide me any insight on what is going on, and where to
> >>
> >> look
> >>
> >> >> to
> >> >> possibly attempt to trace and fix this behaviour?
> >> >>
> >> >> I have an Oregon scientific WMR-968 wirelessweather station that I do
> >>
> >> nt
> >>
> >> >> seem
> >> >> to be able to connect to xastir directly (I tried several
> >>
> >> combinations
> >>
> >> >> of
> >> >> baud rates with no sucess), so wx200d is my only alternative at the
> >> >> moment,
> >> >> and I would also like to be able to use the wx200d daemon to upload
> >>
> >> wx
> >>
> >> >> data
> >> >> to other applications in the future.
> >> >>
> >> >> The above behaviour happens in 1.3.1, 1.3.2 and in a CVS update from
> >> >> last
> >> >> week.
> >> >>
> >> >> Thanks for the help,
> >> >>
> >> >> Sam
> >> >> N8USY
> >> >
> >> > --
> >> > ------------------------------------------------------------------
> >> > Brian D Heaton
> >> > Senior Network Engineer
> >> > Janus Research Group
> >> > (706) 791-8342
> >> > GPG Fingerprint: C99E 3E9C E23A 4E47 46F4 0A77 3A45 CB65 9E19 5B0A
> >
> > --
> > ------------------------------------------------------------------
> > Brian D Heaton
> > Senior Network Engineer
> > Janus Research Group
> > (706) 791-8342
> > GPG Fingerprint: C99E 3E9C E23A 4E47 46F4 0A77 3A45 CB65 9E19 5B0A

-- 
Stefano A M (sam) Lassini stefano at ieee.org
SAM: http://www.iserv.net/~stefano/
N8USY: http://www.qsl.net/n8usy/