Hi Mark; You said: "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." Where nodes keeps cluster stat? When a query comes to a node that is at another shard's replica, how query will return accurately?
2013/5/5 Jack Krupansky <j...@basetechnology.com> > Is soul retrieval possible when ZooKeeper is down? > > -- Jack Krupansky > > -----Original Message----- From: Mark Miller > Sent: Sunday, May 05, 2013 2:19 PM > To: solr-user@lucene.apache.org > Subject: Re: disaster recovery scenarios for solr cloud and zookeeper > > > 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 >> > >
