CLUSTER SLOTS

CLUSTER SLOTS returns the cluster’s slot map: each range of consecutive slots served by one primary, with that primary and its replicas. Many cluster clients read it at startup and after a -MOVED redirect. Newer clients can use CLUSTER SHARDS instead.

Only replicas that can serve reads are listed: a replica marked as failed, or one that has not finished its first sync, is left out.

Return value

An array of ranges. Each range is an array:

1. Start slot (integer).
2. End slot (integer).
3. The primary, then one entry per replica. Each node is an array of:
   • its endpoint (bulk string), as cluster-preferred-endpoint-type chooses: the IP address, the hostname, or nil (RESP2) / null (RESP3) with unknown-endpoint,
   • its client port (integer), the TLS port when you are connected over TLS,
   • its node ID (bulk string),
   • its other addresses: ip when the endpoint is not the IP, and hostname when the node has one and the endpoint is not the hostname, then availability-zone when the node has an availability-zone setting. A map in RESP3, a flat array of pairs in RESP2 (empty when there is nothing to add).

The address and port of a node are the ones it announces to clients: cluster-announce-client-ipv4 and cluster-announce-client-port when it has them, which can differ from the address the nodes use among themselves.

With cluster mode off, the reply is an empty array.

Examples

127.0.0.1:6379> CLUSTER SLOTS
1) 1) (integer) 0
   2) (integer) 5460
   3) 1) "10.0.0.1"
      2) (integer) 6379
      3) "b4240bf759694b9ba85b3b5efd51785b86261c3e"
      4) (empty array)
   4) 1) "10.0.0.4"
      2) (integer) 6379
      3) "80c69623243ebb98309adbe1d4c95f7857e37c2c"
      4) (empty array)
2) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "10.0.0.2"
      2) (integer) 6379
      3) "0e2a97d798979a2e3e5e7f940e2ac533fb36b69b"
      4) (empty array)
   4) 1) "10.0.0.5"
      2) (integer) 6379
      3) "a406ec695ab17e4f731d29cd54e36d4ce81e2c65"
      4) (empty array)
3) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "10.0.0.3"
      2) (integer) 6379
      3) "db0203ba69a674ed0b0cde72c4dfcecc846ed307"
      4) (empty array)
   4) 1) "10.0.0.6"
      2) (integer) 6379
      3) "087d5d8db5c8df0f3152afcd17b94d5879f9107f"
      4) (empty array)

A node started with --availability-zone zone-a, --cluster-announce-hostname host0.example.com, --cluster-announce-client-ipv4 10.0.0.1 and --cluster-announce-client-port 7000 is listed like this (the address and port are the announced client ones, and the map holds the hostname and the zone):

127.0.0.1:7005> CLUSTER SLOTS
1) 1) (integer) 0
   2) (integer) 16383
   3) 1) "10.0.0.1"
      2) (integer) 7000
      3) "7a28581ffafcbe156e07d2e0fc7107eb808e2f1f"
      4) 1) "hostname"
         2) "host0.example.com"
         3) "availability-zone"
         4) "zone-a"

Compatibility

Same layout as Redis 7 and Valkey 8, including the endpoint and the extra address map. The availability-zone entry is Valkey 8.1’s.

See also

CLUSTER SHARDS, CLUSTER NODES, CLUSTER KEYSLOT

In a cluster: Cluster clients