----- Original Message ----- From: "Thomas Pedoussaut" <[EMAIL PROTECTED]> To: "LinuxVirtualServer.org users mailing list." <[email protected]> Sent: Saturday, May 31, 2008 3:00 AM Subject: Re: [lvs-users] Possibly beating a dead horse - IPVS-NAT - 1 Director, 2 Realservers
> Memblin wrote: >> I can get any TCP application to work that I want >> but what we're looking for is a way to load balance >> traffic to our DNS resolvers / caching servers. >> >> I've seen all over the list where people have had problems >> with DNS and other UDP based applications and LVS. >> >> The only problem I have is that all DNS queries that >> come in always go to the same real server. I do get an >> answer back at the client but it's not load balanced of course. >> > Just a few questions: > - what's your LB method ? RR or WRR are the only one working for UDP (no > sessions) I've tried RR and WRR and mixing up the weights > - Can you give us the ouptput of an ipvsadm -ln to check that you > effectively have both weight > 0 > (and is 1 realserver located o the same host as the director ?) bal01:/home/crow# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn UDP <Public VIP>:53 rr -> 192.168.1.3:53 Masq 1 0 0 -> 192.168.1.2:53 Masq 1 0 0 The director and both realservers are seperte hardware Director eth1 - <Public VIP> -> Internet eth0 - 192.168.1.1 -> Switch1 ns2 eth0 - 192.168.1.2 -> Switch1 ns3 eth0 - 192.168.1.3 -> Switch1 The director can ping both realservers the realservers can both ping the director and reach the world through the director. > - Are you proceeding the tests from different clients from different > networks ? There is server affinity in ipvs to "stick" client to > servers. In the same vein, can you check that there is efectively NO > traffic to the second resolver. The clients I am testing with are a machine in a seperate VLAN from the VIP so it goes through a router to get to <Public VIP> and another one from out of state. I both tcpdump and dnstop show the same thing when I fire up the performance test or run manual 'dig @<Public VIP> <domain>'. If I remove the realserver from the ipvs config that is currently getting all the traffice (say num 1), the traffic does go to the other realserver (say num 2). Then when I put number 1 back into the ipvs configuation the traffice stays with number 2. If I do nslookups from a windows box it looks like Windows actually asks for like 8 things per single request and those get spread out between both servers normally. > PS: I know some ISP use anycast for deploying farms of DNS resolvers Some of our networking folks are rather ANYCAST resistant which is why I was looking for a way to load balance this with a server of sorts. I think I may go back and tell them they're going to have to do the ANYTCAST for us. _______________________________________________ LinuxVirtualServer.org mailing list - [email protected] Send requests to [EMAIL PROTECTED] or go to http://lists.graemef.net/mailman/listinfo/lvs-users
