Mailing List Archive

Quoting Marcel Heemst van <MHEE@fuji-ef.nl>:
> But...
> When the terminal server is going down and the conserver was already
> started, console -u NEVER detect the connections down.
> AND
> When the terminal server is going up and the conserver was already
> started,
> console -u NEVER detect the connection up.

This is true. The first issue is that the conserver host isn't seeing any
problem with the TCP connection to the terminal server. If the TCP session
goes down, conserver will notice the problem and bring the consoles to the down
state (and try and reconnect, actually). Usually it only happens when a
terminal server crashes or gets power cycled (it doesn't have a chance to abort
all the TCP connections). There's really not much that can be done here, since
conserver is relying on the underlying TCP stack to do it's job - most
applications would have this same problem (if you were to connect to one of
those consoles and try and interact with it, conserver would immediately get a
TCP failure and bring it down - after trying to reconnect). The idea of having
conserver "ping" the terminal servers to make sure they're up doesn't really
appeal to me (right at this moment), but maybe someone would have a good idea
of how to do this - that way terminal servers that drop off the net (for
whatever reason) would be detected sooner. But, ideally, this is a small edge
case and not the norm (rebooting a terminal server *should* trigger TCP session
closures - at least, if the terminal server was doing "the right thing").

As for the second problem (conserver already running and a terminal server is
booted), there are a couple of options. The first is to use another app to
watch your terminal servers and send conserver a SIGUSR1 whenever it wants
conserver to try and reconnect to all the consoles marked as down. Another
option is to use the -o/-O options and have conserver automatically try and
reconnect all the downed consoles. Between those two methods, I hope something
works for you.

> This problem can we solve with:
> Start a console session to this port and use the ^Eco string.
>
> But we want to have a functionality to redetect the connection state
> automaticly, because we have an another application which is detect
> the
> connection state and generate alarm then the connection is down.

Hopefully one of those methods above works in this case.

Bryan