ZooKeeper allows clients to put watches on paths in the ZK tree. When the cluster state changes, every Solr client is notified by the ZK server and then each client reads the updated state. No polling is needed or even helpful.
In any event, reading from ZK is much more lightweight than writing, because the ZK server keeps all its data in memory and doesn’t have to go through the consensus rigamarole required for a write. On Jun 2, 2014, at 5:17 PM, Jim.Musil <jim.mu...@target.com> wrote: > I’m curious how CloudSolrServer works in practice. > > I understand that it gets the active solr nodes from zookeeper, but does it > do this for every request? > > If it does hit zk for every request, that seems to put a lot of pressure on > the zk ensemble. > > If it does NOT hit zk for every request, then how does it detect changes in > the number of nodes and the status of the nodes? > > Thanks! > Jim M.
