If you used Solr before the release of the 4.0 version, you are probably familiar with replication. The way deployments usually worked is that there was a single master server and multiple slave servers that were pulling the index from the master server. In Solr 4.0, we don't have to worry about replication and pulling interval – it's done automatically. We can also set up our instances in a way to achieve a similar setup as that of multiple replicas of a single shard where data is stored. This recipe will show you how to do it.
If you are not familiar with setting up a SolrCloud cluster, please refer to the Creating a new SolrCloud cluster recipe in this chapter.