Planning your Locator Search SolrCloud setup

Also see Introduction to Multi-Node Installations#NodeInstallations-LargeMulti-NodeSetups.

Each Locator Search Server acts as a node in a SolrCloud index. The index is split into shards. A shard is a logical partition of the index, containing a subset of documents, such that every document is contained in exactly one shard. The shards are automatically distributed between the Locator Search servers in the SolrCloud setup.

Deciding on number of Locator Search Servers

• In testing ayfie has seen the best query performance with 3 SolrCloud shards per Locator search server. 3 shards are default number of shards in a single-node installation.
• A rule of thumb for good query performance is 20 million documents per Locator search server. However, this is a question of cost vs. query performance.
• Consider index growth when planning
• Additional Locator Search servers can be added to an existing SolrCloud setup

Deciding on number of SolrCloud shards

• The number of shards are set on the SolrCloud index creation.
• Choose a number that easily can be divided on number of servers. 6 divides on 2 and 3 Locator Search Servers.

Deciding on replication

See Enable SolrCloud Replication.

• Replication will require double amount of disk space
• Replication can offer load balancing and partial failover. There are other single points of failure in Locator.

Deciding on load balancing

• Load balancing can be configured between all search servers in the SolrCloud setup. Locator ha currently no built-in load balancer, so an external load balancer needs to be used.