Graceful server reloading about ssh-chat HOT 4 OPEN

These might generate some ideas:

1. http://unix.stackexchange.com/questions/27636/how-does-ssh-connection-survive-a-network-restart
2. http://www.cyberciti.biz/faq/if-sshd-is-restart-will-any-connections-be-disconnected/

Edit: They're just TCP sockets at the end of the day, so handling them like an HTTP server with sockets should be the same, right?

from ssh-chat.

DISCLAIMER: very very beginner Go level here, so I may have totally misinterpreted/mystified things, still the project is neat and the problem (graceful restart with persistent connections) is interesting.

Basically, both rcrwoley/goagain and facebookgo/grace provide same way to recover Listener connections from the restarted process (via a clever use of environment variables for passing the number/file descriptors of active listener connections, and then getting back the net connection from the file descriptor).

I guess a similar approach can be replicated on the file descriptors of the active connections but will prove slightly more complicated than with just Listener connection(s) (Accept() makes a very natural point where to break/restart the service and almost no state is carried across restart):

• some state to rebuild clients (from connection file descriptors) should be saved/serialised somewhere;
• client.handleChannels() should be "restart-wise" and handle the restart gracefully (stopping at the "right" point / saving info for restart).

Well, maybe this would just turn out an "ad-hoc, informally specified, implementation of half of a failover proxy frontend".

from ssh-chat.

Maybe a small proxy could be written in Erlang? I dunno, I've just heard people talk about hot code reloading in Erlang.

from ssh-chat.

There's a thread on HN today about graceful server restart with Go: https://news.ycombinator.com/item?id=8772636. Might be of interest to you.

from ssh-chat.