Hi Simon, > > > Hi Gerd, > > On Wed, Sep 02, 2009 at 11:52:17PM +0200, it-intuition wrote: > > Hello, > > > > we are currently using lvs for balancing two webservers by > using the > > wrr scheduler in combination with persistance. Now we want > to modify > > our setup to use one primary webserver and a secondary > webserver as a > > backup server. My idea was to set the weight of the primary > webserver > > to 1000 and for the backup server to 0. > > > > These are the question that came up in my mind: > > > > 1. How will this setup behave if the primary webserver is down? > > I suspect all connections will fail.
That's what I suspected too. > > 2. How will this setup behave if the primary webserver is up again? > > As it did before the primary went down. > > > > 3. Does a weight of 0 mean, that no connection to the backup server > > can be made (if the primary webserver is down)? > > A real-server with a weight of 0 won't get any new > connections, unless they are associated with a recent > connection and the service is marked as persistent. > > In your case, this should mean no, no connections will be > sent to the backup server. > > In short I think the basic effect of this setup would be the > same as not having the backup server in the pool at all. > > > The last question may sound stupid, but I read that a > weight of 0 is > > often used to silently take a server out of a pool. So I think a > > weight of 0 prevents clients to connect; which is not the effect I > > want for our setup. > > > > Any help or comments would be appreciated. > > I think that a better strategy is to have a higher level > monitor looking at your servers and inserting the backup > server into lvs as needed. ldirectord and keepalived should > both be able to do this. Ah, looking from the other side onto the problem. That'a good idea. I think this is the way we go further. > Alternatively, explicit support for this kind of backup > server arrangement could be added to lvs. But it would rely > on a fairly low-level view of weather the primary is up or down. I wouldn't go that far. Ok, if it would be implemented, fine. :) Thanks! Gerd _______________________________________________ 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
