On Thu, Apr 03, 2008 at 04:17:33PM +0200, pierrick grasland wrote: > 1) IMHO, we don't have to allow persistence for more than a call . > > I'm hoping to detect a call Id, set a timer for this call Id, > corresponding to persistence. But a phone call as a very variable > time, from short call (less than 30s) to long call (more than 15 > minutes, and my stats are only based on my bills ^^). > > We can't allow a connexion logged as active for days, but if I'm in > the following case (basic call flow in SIP) : > > Bob = INVITE => proxy1 = INVITE =>LVS = INVITE => realserver (proxy2) > = INVITE ===> Alice > Bob <= 200 OK = proxy1 <= 200 ok = LVS <= 200 ok = realserver > (proxy2)<= 200 ok === Alice > Bob = ACK => proxy1 = ACK =>LVS = ACK => realserver (proxy2) = ACK > =========> Alice > > Bob <==========================RTP===============================> Alice > > Bob <= BYE = proxy1 <= BYE = LVS <= BYE = realserver <= BYE > =============== Alice > Bob = 200 OK => proxy1 = 200 OK =>LVS = 200 OK => realserver (proxy2) > = 200 OK => Alice > > > Then, we don't have SIP messages exchanged during the length of the > communication, which use RTP. But, we must transfer the BYE in order > to close the call. > > I think we have several options here : > - hash (seems practical, but I don't know how it's react in case of > addition / deletion of server) > - timers > - parsing sip headers in order to detect call terminaison, which seems > totally impractical with a DR setup (we don't see all messages > exchange from the 2 clients) Yes, this all sounds very familiar. The parsing approach sounds like a good idea, are you sure that the packet-flow makes it impractical when DR is used? It seems such a shame not to be able to use such a good idea. The timeout idea is the most obvious approach, and probably the best. But really long timeouts might well be needed. I mean, its not uncommon for a phone call to go for several hours. As for the hash, yes, I share your concern there. > So, just for an example, I wish to know how do you implement > persistence for HTTP. > > 2) I'm actually browsing sources from kernel 2.6.24 (just for a better > idea on the architecture). I found IPVS in > linux-2.6.24.4/net/ipv4/ipvs. > Does all sources are located in this folder ? Nothing with netfilter ? There is also a header file, include/net/ip_vs.h IPVS does use some of the netfilter code, but you probably only need to study what is in net/ipv4/ipvs and include/net/ip_vs.h to understand what is going on. > PS : I have time to make something valuable (ie 4 months). I'm in > internship, and this is my subject. > -- > Grasland Pierrick > NEXCOM Systems > LANNION > FRANCE -- Horms -- To unsubscribe from this list: send the line "unsubscribe lvs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
