[wt4hq] HQ Network

[Mario Lorenz]

Am 19. Jun 2009, um 14:43:34 schrieb Dieter Kritzer:
> 
> My info is, that we used the latest version. You and OE9WLJ found some
> problems 2 years ago.
> 

Well, I'd doublecheck. It would be nice if you could try to reproduce the
crash, while having compiled with -ggdb (include debug symbols),
and ulimit -c unlimited, so that a crash will provide a core file.
This core dump can then further be analyzed to find the cause of the crash.

>  
> All our computers had logsync enabled, I think about 20 PCs. My Info is that
> for a synchronisation you have to switch logsync on, otherwise no QSO will
> be sent to the other stations, is that not correct???

Nope.
With Logsync off, all QSOs are still distributed over the network as
soon as they are entered. Thus, if all computers are always online, 
they will all get all QSOs. If however temporarily some connection (or the
server) go down, the QSOs entered during this time are being dropped on
the network (ie, they will only be present in the computer that initially
logged them, and in all other computers that had a network connection).

With LogSync enabled, all the computers will start to periodically verify
that each of them has all the QSOs. So imagine what happens late in the
contest, if, in 20 computers, the number of QSOs does not match.
Hectic gossipping around with neighboring and remote computers ensues
to find out just which QSO it is that is missing. This heavy gossipping
causes further congestion, during which some new ADDQSO messages get lost,
hence the situation worsens, so the network melts.
Please note that within a stable LAN where you have unlimited bandwith, 
this is not an issue, thats why you can choose to logsync only on the local
LAN, and not via the tunnels.

Btw, I do doubt that openvpn or similar will give you a better tunnel, because
then the filtering of the local traffic (local log sync, local dx cluster etc)
will not take place, as you essentially make the other nodes part of your
LAN, but via a heavily bandwith restricted link.

Regards,

Mario
-- 
Mario Lorenz                            Internet:    <ml at vdazone.org>
                                        Ham Radio:   DL5MLO at DB0ERF.#THR.DEU.EU
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