[RADIATOR] Question regarding MaxTargetHosts

[Jani Lahti]

Hello Patrik

Heikki assumed that Host 1 and Host 3 are already marked as unavailable
inside Radiator (and are within FailureBackoffTime period). Those two are
automatically skipped and not counted against MaxTargetHosts. So Host 4 is
reachable within MaxTargetHosts limit.

I assumed that the status of the backend servers is not known at the start,
so Radiator checks the first two, marks them bad (FailureBackoffTime) and
gives up for the first request. If the second request comes in only
after FailureBackoffTime has passed, this same scenario repeats. If the
second request comes in within FailureBackoffTime, the last 2 remaining
backends are tried, and Host 4 can indeed respond with reject.

//jani

On Mon, 12 Jan 2026 at 09:28, Patrik Forsberg via radiator <
radiator at lists.open.com.au> wrote:

>
> Getting conflicting responses.. Jani Lahti says it wont reach Host 4 while
> you say it should ?
>
> IMHO from reading the documentation it should reach Host 4 for the same
> reason you describe but just wanted to make sure that is how it's supposed
> to be working, I have yet to try this in a real-world scenario tho.
>
> Patrik Forsberg
>
>
> > -----Original Message-----
> > From: radiator <radiator-bounces at lists.open.com.au> On Behalf Of
> Heikki Vatiainen via radiator
> > Sent: den 29 december 2025 14:18
> > To: radiator at lists.open.com.au
> > Subject: [RADIATOR] Question regarding MaxTargetHosts
> >
> > Patrik Forsberg wrote:
> >
> > > Have a small question regarding MaxTargetHosts in AuthBy Radius.
> > > Will this limit the number of hosts ask regardless of the hosts status
> or if the
> > hosts is unavailable for the moment will the request continue on without
> > counting it against this counter ?
> >
> > A working Host is looked up first and only those that should be working
> are
> > counted against MaxTargetHosts limit. In other words, it doesn't count
> Hosts
> > that are unavailable.
> >
> > > Say I have MaxTargetHosts set to 2
> > > Host 1 - is unavailable/down
> > > Host 2 - is available - doesn't respond (request ignored) Host 3 - is
> > > unavailable/down Host 4 - is available - responds with a reject
> > >
> > > Will it ever reach Host 4 as long as MaxTargetHosts is set to 2 ?
> >
> > It will reach Host 4. Hosts 1 and 3 are never considered.
> >
> > Hosts 1 and 3 are immediately skipped until the failure backoff time or
> Status-
> > Server brings them up again. If you see different results, please let us
> know. It
> > should act as a limit of trying hosts that should work.
> >
> > With a number of retries and multiple hosts, the eventual response may
> come
> > long after a client has already given up when some hosts should be
> working
> > but they don't respond.
> >
> > Heikki
>
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