If you¹re using SolrJ, CloudSolrServer exposes the information you need directly, although you¹d have to poll it for changes. Specifically, this code path will get you a snapshot of the clusterstate: http://lucene.apache.org/solr/4_5_0/solr-solrj/org/apache/solr/client/solrj /impl/CloudSolrServer.html#getZkStateReader()
http://lucene.apache.org/solr/4_5_0/solr-solrj/org/apache/solr/common/cloud /ZkStateReader.html#updateClusterState(boolean) http://lucene.apache.org/solr/4_5_0/solr-solrj/org/apache/solr/common/cloud /ZkStateReader.html#getClusterState() If you¹re not using SolrJ, or don¹t want to poll, you really only need a zookeeper client. As Shawn Heisey suggests, you put a watch on the clusterstate.json, and write something to determine if the change was relevant to you. A few months ago I wanted to do analysis of changes in my SolrCloud cluster, so I threw together something using the Curator library to set watches on clusterstate.json and commit the new version to a local git repo whenever it changed. (https://github.com/randomstatistic/git_zk_monitor) The hardest part turned out to be learning about the Zookeeper watch semantics, but you could use any client you like. On 7/3/14, 9:23 AM, "Shawn Heisey" <s...@elyograg.org> wrote: >On 7/3/2014 7:49 AM, Ugo Matrangolo wrote: >> I would like to be informed as soon as a cluster event happens like a >>node >> dropping and/or starting a recovery process. >> >> What is the best way (if any) to listening on SolrCloud events ? > >I don't know how it's done, but if you are using SolrJ and >CloudSolrServer, you have access to the zookeeper client. With the >zookeeper client, you can put a watcher on various parts of the >zookeeper database, which should fire whenever there is a change. > >Thanks, >Shawn >
