redis and cluster | Mar 13, 2016 • Ding Jiao

CLUSTER INFO provides INFO style information about Redis Cluster vital parameters. The following is a sample output, followed by the description of each field reported.

  • cluster_state: State is ok if the node is able to receive queries. fail if there is at least one hash slot which is unbound (no node associated), in error state (node serving it is flagged with FAIL flag), or if the majority of masters can’t be reached by this node.
  • cluster_slots_assigned: Number of slots which are associated to some node (not unbound). This number should be 16384 for the node to work properly, which means that each hash slot should be mapped to a node.
  • cluster_slots_ok: Number of hash slots mapping to a node not in FAIL or PFAIL state.
  • cluster_slots_pfail: Number of hash slots mapping to a node in PFAIL state. Note that those hash slots still work correctly, as long as the PFAIL state is not promoted to FAIL by the failure detection algorithm. PFAIL only means that we are currently not able to talk with the node, but may be just a transient error.
  • cluster_slots_fail: Number of hash slots mapping to a node in FAIL state. If this number is not zero the node is not able to serve queries unless cluster-require-full-coverage is set to no in the configuration.
  • cluster_known_nodes: The total number of known nodes in the cluster, including nodes in HANDSHAKE state that may not currently be proper members of the cluster.
  • cluster_size: The number of master nodes serving at least one hash slot in the cluster.
  • cluster_current_epoch: The local Current Epoch variable. This is used in order to create unique increasing version numbers during fail overs.
  • cluster_my_epoch: The Config Epoch of the node we are talking with. This is the current configuration version assigned to this node.
  • cluster_stats_messages_sent: Number of messages sent via the cluster node-to-node binary bus.
  • cluster_stats_messages_received: Number of messages received via the cluster node-to-node binary bus.

More information about the Current Epoch and Config Epoch variables are available in the Redis Cluster specification document.


@bulk-string-reply: A map between named fields and values in the form of <field>:<value> lines separated by newlines composed by the two bytes CRLF.