multi home network handling not falling back to v4 about nats-pure.rb HOT 8 CLOSED

Published new release of the gem with your fixes so closing this one for now, thanks!
https://github.com/nats-io/pure-ruby-nats/releases/tag/v0.1.2

from nats-pure.rb.

After some more digging into this I think the problem is much simpler luckily

• it IS connecting to all the addresses, v4 and v6, so thats great
• it is not always trying the v6 address before the v4 address, this is probably wrong but lets ignore that for now, I could make that into a different ticket
• When connecting it always tries all the servers found in DNS and doesn't stop when it finds a good connection https://github.com/nats-io/pure-ruby-nats/blob/60a958b896a219cf0e5dbf9cd7132d4b1959e50a/lib/nats/io/client.rb#L972

So simply changing that to:

        addrinfo.each_with_index do |ai, i|
          begin
            @socket = connect_addrinfo(ai, @uri.port, @connect_timeout)
            break
          rescue SystemCallError
            # Give up if no more available
            raise if addrinfo.length == i+1
          end
        end

ie. breaking if the socket connect_addrinfo doesn't raise any errors - ie. we're connected - then this all works

Some extra error callbacks would still be good

from nats-pure.rb.

PR addresses the stuff I mentioned - except for the V6 first.

@wallyqs you're free to discard and do whatever you prefer, there doesnt seem to be test coverage for the Socket class so I didnt add any tests

from nats-pure.rb.

Good catch... Merged your changes after adding some minor changes to the spec. I will take a look at the ipv4/ipv6 connection preference and update here too. Thanks for the PR and the feedback!

from nats-pure.rb.

Seems that since right now we are relying on the default behavior from Socket.getaddrinfo for the ordering of the list of endpoints to attempt to connect, and since it looks like that result already went through from what is defined in the RFC-3484 and RFC-6724 standards, think we can probably leave as is for now, and letting the user determine the ipv6 ordering by tuning /etc/gai.conf to set the precedence of address families to try when connecting as it is suggested in those RFCs.

from nats-pure.rb.

That's what I thought but my machines are configured for IPv6 priority already - and works for other stuff. Not to worry I will investigate further and if I can narrow it down to either environment or code I will make a new ticket. For now happy to close this one

from nats-pure.rb.

As a separate issue sounds good for now, we could add a sort_by ipv6 before attempting to connect ( (wallyqs/pure-ruby-nats@48dfda9d5967fc17832e565817e3ee64ff368937)[example]) so that those addresses are tried first but just not sure whether that is correct. Thanks again.

from nats-pure.rb.

Yeah, I'll investigate more - probably in a few weeks.

Happy to close this and hopefully we get a release soon :)

from nats-pure.rb.