rqlite supports adding read-only nodes. You can use this feature to add read scalability to the cluster if you need a high volume of reads, without adding write latency to the cluster.
What this means is that a read-only node doesn't participate in the Raft consensus system i.e. it doesn't contribute towards quorum, nor does it cast a vote during the leader election process. However it does subscribe to the stream of committed log entries, which are broadcast by the leader. It updates its own copy of the SQLite database, just like any other node in the cluster.
Querying a read-only node
Any read request to a read-only node must specify read-consistency level
none. If any other consistency level is specified (or none at all) the read-only node will redirect the request to the leader.
Enabling read-only mode
rqlited to enable read-only mode.
Read-only node management
Otherwise read-only nodes join a cluster in the same manner as a voting node. They can also be removed using the same operations.