Re: Proxy home server failover

[Alan Dekok <aland@deployingradius.com>]

Tomas Hoger wrote:
> I have a question regarding proxy failover in FreeRadius 1.x.  Proxy
> code chooses first active home server for realm and send packet to
> that one.  If no reply is received after configured number of retries,
> request is rejected, other servers are *not* tried.

  Yes.

>   Does version 2.0
> have the same behavior?  According to comments in sample proxy.conf it
> seems new version will also try only one server and reject request if
> no reply is received.

  That's not what the documentation says.  It says that a request will 
be rejected once it has timed out.  If the home server is marked dead 
while the request is still alive, AND the NAS retransmits, then the 
request will be sent to another home server.

> I have made a quick modification of request_list.c, so that
> request_reject is not called when try_count drops to 0.  After that,
> when NAS retries, different home server is selected.  Can not calling
> request_reject have any negative impact (memory leak, internal
> structures inconsistency, ...)?

  No.

>  Wouldn't it make sense to make
> configuration parameter, which will instruct radiusd whether it should
> reject or silently drop request, for which it has not received reply
> from home server?

  In 2.0.0, the request is automatically sent to another home server in 
the same server pool.  If there is no response, the post-proxy-type 
"fail" section is run.

>  For realms with single home server, it won't make
> much difference, as request will be rejected on next NAS retry (all
> home servers are marked dead), but for realms with multiple home
> servers, reject will not be sent just because one of the home servers
> is not responding.

  Various hacks can be added to 1.1.x, but the problem is deeper than 
that.  The code in 1.1.x isn't easy to debug or modify.  The code in 2.x 
is much clearer, better organized, and supports *much* more 
functionality than 1.1.x.

  At this point, new features will not be added to 1.1.x.  If you want 
new features, use 2.0.0 when it comes out.

  Alan DeKok.