Re: Bug or enhancement on Haproxy 1.3.14.2

Hi Willy,

On Mon, Mar 31, 2008 at 7:36 AM, Willy Tarreau <w#1wt.eu> wrote:

> Hi Romuald,
>
> On Thu, Mar 27, 2008 at 11:02:11AM +0100, Romuald du Song wrote:
> > Hy everybody,
> >
> > When we change our haproxy configuration file we use those switches :
> > /usr/local/sbin/$BASENAME -D -f $CONFIG -p $PIDFILE -sf $(cat $PIDFILE)
> >
> > to relaunch haproxy. It works allrigth.
> >
> > But if there is a new proxy defined on a port that haproxy cannot bind
> on
> > haproxy quits. So all your services are down !
> >
> > I'd rather like it to keep serving other proxies.
> >
> > Does it make sense to anyone else ?
>
> Seems strange to me, because the old process only goes away once the new
> one has *completely* started.
>
> On systems with SO_REUSEPORT (*BSD, patched linux), the start up goes
> like this :
>
> - new process reads conf
> - new process binds to all ports
> - new process sends SIGUSR1 to old processes ($PIDFILE)
> - old processes finish current sessions then exit
>
> On systems without SO_REUSEPORT (linux, solaris, ...) what happens in
> your case above becomes this :
>
> - new process reads conf
> - new process tries to bind to all ports. One conflict is found,
> the error is marked retryable, so the new process stops binding
> itself to every port.
> - new process sends SIGTTOU to old processes ($PIDFILE)
> - old process stops listening to all ports
> - new process binds to all ports.
> - if binding works, new process sends SIGUSR1 to old processes
> ($PIDFILE),
> which finish current sessions then exit
> - if binding fails, new process stops listening, sends SIGTTIN to old
> processes ($PIDFILE), which then re-enables listening on old sockets,
> and continues its work.
>
> If this is not what you have observed, obviously there is a problem
> somewhere.
> What precise system (and version) are you running this on, and what
> haproxy
> version ? If you could send a small configuration which triggers the
> problem,
> it would help a lot.
>
> Regards,
> Willy
>
>

My system is :
Linux XXXX 2.6.18-4-amd64 #1 SMP Fri May 4 00:37:33 UTC 2007 x86_64 GNU/Linux

which is the debian stable linux kernel and I run haproxy-1.3.14.2 .

The message I receive is :
[ALERT] 090/091315 (16440) : Starting proxy YYYYYY: cannot bind socket

Also in my test case no traffic is handled by old haproxy instance. I create a new listen proxy to bind on an address which is already used on my system (obviously
 it's an error) and then I reload haproxy.

I've joined my configuration file (modified for privacy).

Thanks for you attention.

-- 
-Tout ce qui n'est pas donné est perdu - Hasari Pal




application/octet-stream attachment: haproxy.cfg