Hello Jose, On Fri, Oct 18, 2013 at 06:49:47PM +0000, Olcese, Jose wrote: > Hello, > > I'm facing the following problem: > > I use stickiness table on a peers cluster. If I reload the configuration > without changing any backend server, everything works fine. > > Reload command: > /usr/local/sbin/haproxy -f /usr/local/etc/haproxy.cfg -p /var/run/haproxy.pid > -D -sf $(cat /var/run/haproxy.pid) > > > The problem happens if I add or remove backend servers to the config file. > The stickiness table will maintain the index to the original servers' order > so the "reloaded" table will point to wrong servers.
This is normal and expected : the servers' IDs are the only stable information across reloads and the only one that can reliably be shared between multiple peers. If you need to insert or remove servers in the middle, then you need to force the servers' IDs using the "id" argument. The ID is per-backend, so there is no problem if your IDs overlap between some backends. IDs are 32-bit, so you can easily have your config generator produce them incrementally I think. BTW, I'm seeing below that it seems to name them with a 32-bit ID as well. I'm even thinking that your config generator is *really* dumb in that it does not respect *at all* the servers order and just dumps them in the numeric order of their IDs : server vm--i-37a49303 172.18.80.106 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-43279674 172.18.80.60 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-76afe142 172.18.81.100 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-b2f3a386 172.18.80.103 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-b40a3a80 172.18.81.165 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-bcc96e8b 172.18.81.29 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-cfa3b8fb 172.18.81.80 check port 80 inter 30s fastinter 5s rise 2 fall 3 That would be terrible for a farm working with a hash-based algorithm. Think about a cache, you would shuffle all the data on each addition/removal! But if that's OK for your usage, then you could probably make it pass the ID in integer as the "id" parameter : server vm--i-37a49303 172.18.80.106 id 933532419 check port 80 inter 30s fastinter 5s rise 2 fall 3 server vm--i-43279674 172.18.80.60 id 1126667892 check port 80 inter 30s fastinter 5s rise 2 fall 3 If your config generator cannot do that, a simple awk or even perl script will easily do it for you. Hoping this helps, Willy
