Cluster Operations

Introspection

SHOW CLUSTER;
SHOW NODES;
SHOW RAFT GROUPS;

Adding Nodes

New nodes join the cluster and receive vShard assignments during rebalancing.

Shard Rebalancing

When nodes join or leave, vShards redistribute automatically:

1. Coordinator selects vShards based on load metrics
2. Target node replicates the vShard's data
3. Ownership transfers atomically
4. Old node drops the vShard data

Transparent to clients — requests forward during migration.

Rolling Upgrades

1. Drain a node (move its vShard leadership to other nodes)
2. Upgrade the binary
3. Restart the node
4. Repeat for each node

Raft leader election handles temporary unavailability.

Failure Recovery

• Single node failure — Raft elects new leaders for affected vShards
• Minority failure — Cluster remains available with quorum
• Majority failure — Cluster becomes read-only until quorum restores