Maintenance mode¶

In this mode, the node is not reachable from the outside, i.e.

• it refuses all incoming RPC connections,

• it does not join the cluster, thus

  • all operations that need synchronizing with other nodes are disabled (e.g. schema changes),

  • all cluster-wide operations are disabled for this node (e.g. repair),

  • other nodes see this node as dead,

  • cannot read or write data from/to other nodes,

• it does not open Alternator and Redis transport ports and the TCP CQL port.

The only way to make CQL queries is to use the maintenance socket. The node serves only local data.

To start the node in maintenance mode, use the –maintenance-mode true flag or set maintenance_mode: true in the configuration file.

REST API works as usual, but some routes are disabled:

• authorization_cache

• failure_detector

• hinted_hand_off_manager