diff --git a/docs/architecture/raft.rst b/docs/architecture/raft.rst index a6a606a7a2..e9f3e79731 100644 --- a/docs/architecture/raft.rst +++ b/docs/architecture/raft.rst @@ -219,6 +219,36 @@ of nodes in the cluster is available. The following examples illustrate how Raft In summary, Raft makes schema changes safe, but it requires that a quorum of nodes in the cluster is available. +.. _raft-topology-changes: + +.. only:: opensource + + Consistent Topology with Raft :label-caution:`Experimental` + ----------------------------------------------------------------- + + ScyllaDB can use Raft to manage cluster topology. With Raft-managed topology + enabled, all topology operations are internally sequenced in a consistent + way. A centralized coordination process ensures that topology metadata is + synchronized across the nodes on each step of a topology change procedure. + This makes topology updates fast and safe, as the cluster administrator can + trigger many topology operations concurrently, and the coordination process + will safely drive all of them to completion. For example, multiple nodes can + be bootstrapped concurrently, which couldn't be done with the old + gossip-based topology. + + Support for Raft-managed topology is experimental and must be explicitly + enabled in the ``scylla.yaml`` configuration file by specifying + the ``consistent-topology-changes`` option: + + .. code:: + + experimental_features: + - consistent-topology-changes + + As with other experimental features in ScyllaDB, you should not enable this + feature in production clusters due to insufficient stability. The feature + is undergoing backward-incompatible changes that may prevent upgrading + the cluster. .. _raft-handling-failures: