On 4/30/2018 12:03 PM, Monica Skidmore wrote: > As we try to set up an external load balancer to go between two clusters, > though, we still have some questions. We need a way to determine that a node > is still 'alive' and should be in the load balancer, and we need a way to > know that a new node is now available and fully ready with its replicas to > add to the load balancer.
Disclaimer: I am not using SolrCloud mode for the systems that I have behind a load balancer. But this should work for SolrCloud mode too. Use the ping handler for your load balancer health checks. http://server:port/solr/collection/admin/ping You can configure the ping handler however you wish in solrconfig.xml if you want it to do something different than it does by default. > How does ZooKeeper make this determination? Does it do something different > if multiple collections are on a single cluster? And, even with just one > cluster, what is best practice for keeping a current list of active nodes in > the cluster, especially for extremely high query rates? ZooKeeper doesn't make ANY determination about whether a Solr node is up. It has zero knowledge about Solr. The information about which Solr nodes/collections are operational is stored in the ZK database, but ZK itself doesn't know anything about it. I do not know what Solr does to determine which nodes are up. Thanks, Shawn
