CoreMedia applications are configured with property solr.url to connect to one or more Solr instances.

Content Feeder, CAE Feeder and Elastic Social worker applications must be configured to connect to the Solr leader, because all indexing requests are handled by the leader.

Studio should also be configured to query the Solr leader to use the most up-to-date index. Solr followers lag some seconds behind and editors would not be able to find newly created content immediately in Studio. The default replication poll interval is set to 20 seconds, and such a delay is not desirable in Studio search results.

The Content Application Engine can be configured to connect to multiple Solr followers. To this end, a comma-separated list of Solr URLs can be configured in property solr.url. The CAEs will then use a simple round robin load balancing with automatic failover when a server goes down.