[sr-dev] handling failed t_relay() when multiple usr locations

[Andrei Pelinescu-Onciul]

On Mar 08, 2010 at 22:01, I?aki Baz Castillo <ibc at aliax.net> wrote:
> El Lunes 08 Marzo 2010, I?aki Baz Castillo escribi?:
> > El Lunes 08 Marzo 2010, Juha Heinanen escribi?:
> > > Alex Balashov writes:
> > >  > But when does t_relay() itself ever fail due to endpoint reachability
> > >  > issues?  I think t_relay() only fails for formal reasons, like host
> > >  > name lookup failure, invalid address format, etc?  Otherwise, it
> > >  > returns success;  if the endpoint is not reachable, the transaction
> > >  > simply times out.  If this is the case, branch route does get called.
> > >
> > > my understanding is that t_relay calls a branch route always if
> > > t_on_branch is used to set it.  then in that branch route, you should be
> > > able to call set_forward_no_connect().
> > 
> > I really though that t_relay() fails (return a negative code and doesn't
> > invoke a loaded branch_route) in case the TCP cannot be established. Am I
> > wrong?
> 
> Yes I'm wrong. t_relay() doesn't fail (doesn't return a error) in case a TCP 
> connection can not be established. If you set branch_route before it will be 
> executed and ~10 seconds later (configurable) you get the TCP error:
> 
>   ERROR:core:tcp_blocking_connect: timeout 10 s elapsed from 10 s
>   ERROR:core:tcpconn_connect: tcp_blocking_connect failed

That's because you're in tcp non-async mode (not recommended in general,
unless you have to use tls).

Andrei