ha-proxy and keepalived

asked 2017-03-17 05:47:28 -0500

aab gravatar image

I have somequestions,

  1. Does HA-Proxy forward the request to every host which have hosted the same service (lets say Swift) ? Otherwise some nodes (hosting same service) would be lagging behind i.e. each node might not be able to maintain the right state, isn't it ?

  2. How does the keepalived works, I assume that in a cluster of three nodes lets say hosting Glance, only one node will be active and respond to the request, so how do the other two nodes get synced ?

edit retag flag offensive close merge delete


The state is in a database, which should also be deployed as highly-available (usually a Galera cluster). Thus, the state has nothing to do with HA-Proxy.

Bernd Bausch gravatar imageBernd Bausch ( 2017-03-17 21:10:13 -0500 )edit

Typical setup: HA-Proxy is deployed to all controllers, but only one of them is active. Keepalived detects that the controller with the active HA-Proxy is down and moves the Virtual IP to one of the other controllers, thereby activating the HA-Proxy running there.

Bernd Bausch gravatar imageBernd Bausch ( 2017-03-17 21:11:59 -0500 )edit