> -----Ursprüngliche Nachricht----- > Von: Jim Jagielski > Gesendet: Mittwoch, 13. Februar 2008 18:52 > An: dev@httpd.apache.org > Betreff: Re: ping for http in mod_proxy > > > On Feb 13, 2008, at 12:27 PM, Plüm, Rüdiger, VF-Group wrote: > > > > > > >> -----Ursprüngliche Nachricht----- > >> Von: Akins, Brian > >> Gesendet: Mittwoch, 13. Februar 2008 18:23 > >> An: dev@httpd.apache.org > >> Betreff: Re: ping for http in mod_proxy > >> > >> On 2/13/08 11:07 AM, "Jim Jagielski" <[EMAIL PROTECTED]> wrote: > >> > >>> I've started looking at adding "ping" support for > >>> mod_proxy_http to complement whats in mod_proxy_ajp... > >>> The idea is to send a simple OPTIONS * to the backend > >>> and hope for a reply. > >> > >> > >> Would it be more useful to have active healthchecking to > >> backend servers? > > > > This does not help with race conditions on HTTP keepalive > connections. > > We will never be able to completely avoid race conditions... > whether keepalives are in place or not.
But at least the one that comes from the keepalive timer expiring on the backend at the same time I sent the request to it. If the backend answered to OPTIONS * on a keepalive connection it is reasonable to assume that the keepalive timeout will not expire until the real request hit the backend. Regarding other races I agree, but I think the above one is the one that is hit most frequently. Regards Rüdiger
