On 4/17/2016 10:35 PM, John Bickerstaff wrote: > My prior use of SOLR in production was pre SOLR cloud. We put a > round-robin load balancer in front of replicas for searching. > > Do I understand correctly that a load balancer is unnecessary with SOLR > Cloud? I. E. -- SOLR and Zookeeper will balance the load, regardless of > which replica's URL is getting hit?
Your understanding is correct -- queries sent to a single SolrCloud node will be balanced across the cloud, although the node you are sending the queries to might represent a single point of failure. If your program is written in Java, you can use CloudSolrClient in SolrJ -- this client talks to the zookeeper ensemble and dynamically adjusts to the addition and removal of Solr nodes in the cloud. All notifications from the cloud to the client about servers going up or down are nearly instantaneous -- the client does not need to poll for status. For other programming languages, if your client code is not capable of failing over to a second node when the primary goes down, then you would still need a load balancer. Thanks, Shawn
