MongoDB Documentation, Release 3.0.4 { "_id" : "chunksize", "value" : 64 } { "_id" : "balancer", "stopped" : false } config. shards Internal MongoDB Metadata Internal MongoDB Metadata The config (page 738) database is internal: applications and administrators should not modify or depend upon its content in the course of normal operation. The shards (page 742) collection represents each shard in the cluster in a separate document. If the shard is a replica set, the host field displays the name of the replica set, then a slash, then the hostname, as in the following example: { "_id" : "shard0000", "host" : "shard1/localhost:30000" } If the shard has tags (page 682) assigned, this document has a tags field, that holds an array of the tags, as in the following example: { "_id" : "shard0001", "host" : "localhost:30001", "tags": [ "NYC" ] } The config (page 738) database is internal: applications and administrators should not modify or depend upon its content in the course of normal operation. The tags (page 742) collection holds documents for each tagged shard key range in the cluster. The documents in the tags (page 742) collection resemble the following: { "_id" : { "ns" : "records.users", "min" : { "zipcode" : "10001" } }, "ns" : "records.users", "min" : { "zipcode" : "10001" }, "max" : { "zipcode" : "10281" }, "tag" : "NYC" } Internal MongoDB Metadata The config (page 738) database is internal: applications and administrators should not modify or depend upon its content in the course of normal operation. The version (page 742) collection holds the current metadata version number. This collection contains only one document: To access the version (page 742) collection you must use the db.getCollection() method. For exam- ple, to display the collection’s document: mongos> db.getCollection("version").find() { "_id" : 1, "version" : 3 } Chapter 10. Sharding 742 config. tags config. version