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
