Okay. I've finally had time to come back to this. I've looked over your latest message and now think I'm kinda stuck.
I checked /var/log/messages and see those same nanny messages like this: Nov 2 11:59:20 omsbuild nanny[25772]: READ to 192.168.18.29:80 timed out but I don't see anything more from nanny on my system. Is there another place on the server I can get nanny log information? The ipvsadm commands are helpful to know, yet there isn't much for them to report right now: [r...@omsbuild ~]# ipvsadm -L IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP ganassi.radius.co:webcache lc [r...@omsbuild ~]# ipvsadm -L --stats IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Conns InPkts OutPkts InBytes OutBytes -> RemoteAddress:Port TCP ganassi.radius.co:webcache 0 0 0 0 0 Can you think of anything else I can do to find more clues on what might be the matter? Thank you! Mike On 26/10/2009, Graeme Fowler <[email protected]> wrote: > On Mon, 2009-10-26 at 11:18 -0700, mojorising wrote: >> Thanks a lot for your response. It helps me understand a bit more >> about how LVS works. > > Grand :) > >> So, as I mentioned in my first post, "The web servers are up and >> running. I can download web pages successfully from them from my >> desktop as well as directly from the >> load balancer with netcat or similar." I just checked again and I can >> download web pages from the real servers on port 80 with netcat or >> telnet from the LVS machine. So we're all good there. Now I'm >> wondering why nanny might have issues talking to the real servers on >> 80. > > Only you can tell that one I'm afraid. Have you checked the logs which > nanny produces? > >> As for the bits about the configuration, yes. You are right. I just >> verified the IP addresses in the configuration and the ones I am >> testing with via netcat and telnet are the same. > > Good. > >> With respect to the former, if nothing is listening on the load >> balancer, maybe I am trying to use it the wrong way. On other load >> balancers I have used, such as pen or BigIP, the load balancer is >> actually listening and waiting for TCP connections, which it then >> forwards on to the "balanced" nodes (real servers) on specified ports. >> Basically, as far as PCs browsing the balanced sites know, that load >> balancer *is* the web server. Does that make sense? So when I go to >> test those load balancers to see if they work, I check to make sure >> they are listening on the approriate port and try to connect to them >> in the same way I would connect to a real server directly. Am I >> supposed to be doing things differently with LVS? > > The two devices/systems you mention can work in mixed modes; > "directing" (load balancing at L4) or "proxy" (load balancing at L7). L7 > apps must first terminate the TCP session themselves before sending > making a further L7 connection on to the server. > > LVS works at L4 - TCP or UDP. It is not application aware, and it only > ever routes packets based on some rule it's configured with. That's it, > in a nutshell. > > To the client, as you state, the load balancer *is* the webserver as > they connect to an IP address (the VIP) and replies come back from that. > At the TCP or UDP level, the client application is unaware of the magic > going on at the other end of the connection. > > To check how LVS is configured, you can either rely on nanny to tell you > (how? I don't know) or use the ipvsadm command line tool: > > ipvsadm -L # displays LVS table > ipvsadm -L --stats # displays usage stats > ipvsadm -L --rate # displays rate statistics > [the -n switch can be used for numerical output] > > It's worth remembering at this point that nanny is an abstraction layer > away from what's really going on behind the scenes; it monitors the > servers and puts them into/takes them out of the server "pool" as > necessary. It doesn't really do *any* load balancing itself. > > Graeme > > > _______________________________________________ > Please read the documentation before posting - it's available at: > http://www.linuxvirtualserver.org/ > > LinuxVirtualServer.org mailing list - [email protected] > Send requests to [email protected] > or go to http://lists.graemef.net/mailman/listinfo/lvs-users > _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - [email protected] Send requests to [email protected] or go to http://lists.graemef.net/mailman/listinfo/lvs-users
