When Solr loses it's connection to ZooKeeper, updates will start being rejected. Read requests will continue as normal. This is regardless of how long ZooKeeper is down.
So it's pretty simple - when you lost the ability to talk to ZK, everything keeps working based on the most recent clusterstate - except that updates are blocked and you cannot add new nodes to the cluster. You are essentially in steady state. The ZK clients will continue trying to reconnect so that when ZK comes back updates while start being accepted again and new nodes may join the cluster. - Mark On May 3, 2013, at 3:21 PM, Dennis Haller <dhal...@talenttech.com> wrote: > Hi, > > Solr 4.x is architected with a dependency on Zookeeper, and Zookeeper is > expected to have a very high (perfect?) availability. With 3 or 5 zookeeper > nodes, it is possible to manage zookeeper maintenance and online > availability to be close to %100. But what is the worst case for Solr if > for some unanticipated reason all Zookeeper nodes go offline? > > Could someone comment on a couple of possible scenarios for which all ZK > nodes are offline. What would happen to Solr and what would be needed to > recover in each case? > 1) brief interruption, say <2 minutes, > 2) longer downtime, say 60 min > > Thanks > Dennis
