Outstanding requests increasing until max_outstanding

[Alan DeKok]

On Oct 27, 2015, at 1:56 PM, Louis Munro <lmunro at inverse.ca> wrote:
> I have a pair of FreeRADIUS (2.2.5) servers acting as load-balancers for a pool of authentication servers behind them that has been running flawlessly for about a year except for one thing.
> ...
> Where I believe the last column is the number of outstanding requests for each home server (please enlighten me if I am wrong about that).

  Yes.

> And last Friday one of the counters hit 65535 and all proxying to that home server stopped even though it was still responding (and was marked “alive”).

  That's bad.

> I believe that counter is incremented once every time a request is proxied and (should be) decremented every time a reply is received or it times out.
> It does look though like there may be a case where the counter is not decremented.

  Yes.

> So my questions are: 
> 
> 1. Do I understand this correctly? 

  Yes.

> 2. Is this a known issue? 

  No.

> 3. If so, is it fixed in the latest of v2? or v3? 

  I haven't seen it.  I'm not sure what's going on.

  On a quick review of the code, everything looks fine in v2.  But there's the possibility that it's not.

  The code in v3 is simpler.  There's only one place where the count is incremented, and only one place where it's decremented.

> 4. If it’s not an issue, what could I be doing wrong? 

  Nothing.

> I have no problem with the answer being “Upgrade” as long as I know that this is something that is indeed fixed in the version I’ll be upgrading to.
> These servers have performed so well up to now that I have not had a compelling case for upgrading. This could be just it.

  Quite possibly.

  TBH, I'd try 2.2.9.  You can build a local version and try it without replacing the existing binaries.  If it works... that's fixed.  Otherwise, I'd suggest trying 3.0.10.  But that's a lot more work to upgrade to.

  Alan DeKok.