# system.clusters Contains information about clusters available in the config file and the servers in them. Columns: ```text cluster String – Cluster name. shard_num UInt32 – Number of a shard in the cluster, starting from 1. shard_weight UInt32 – Relative weight of a shard when writing data. replica_num UInt32 – Number of a replica in the shard, starting from 1. host_name String – Host name as specified in the config. host_address String – Host's IP address obtained from DNS. port UInt16 – The port used to access the server. user String – The username to use for connecting to the server. ```