Investigating Slow RADIUS Proxy Request

[Alan DeKok]

On Sep 26, 2024, at 12:44 AM, Vedsar Kushwaha via Freeradius-Users <freeradius-users at lists.freeradius.org> wrote:
> 
> I have a few questions about how the FreeRADIUS proxy handles requests:
> 
>  1.  When proxying a request, does a FreeRADIUS thread remain blocked until a response is received from the home server?

  No.

>  2.  Does the max_outstanding flag apply only to health status checks, or does it affect all requests proxied to the home server?

  Why would it apply to health checks?

  I applies only to proxied packets, as the documentation says.

>     *   If a FreeRADIUS thread blocks while waiting for a response, does increasing max_outstanding to a high value like 65536 actually allow FreeRADIUS to send that many outstanding requests? Or is the number of threads the limiting factor?

  No.

>     *   If a proxy request doesn't block a thread, how does FreeRADIUS listen for responses from the home server?

  If you're interested in technical details, the source code is available.

>  1.  We have a request that took 40 minutes to proxy. The snippet below, along with the complete log, shows the details. We're trying to investigate the cause of this delay.
> 
> ```
> 2024-09-17T13:05:52.495Z (44469) Starting proxy to home server 129.170.130.4 port 2083
> 2024-09-17T13:05:52.495Z (44469) server VS_P_790be815-af8f-4dc5-b8c2-e01b8a107db4 {
> 2024-09-17T13:05:52.495Z (44469) }
> 2024-09-17T13:46:55.967Z (44469) Proxying request to home server 129.170.130.4 port 2083 (TLS) timeout 30.000000
> ```

  This is an issue which was fixed in 3.2.6.  We're releasing 3.2.7 shortly to fix a few other issues we found.

  Alan DeKok.