New in version 3.4.

Returns a document that contains information about the status of the balancer.

You can only issue the balancerStatus against the admin database.

The command takes the following form:

db.adminCommand( { balancerStatus: 1 } )

Output Document

The following is an example of a document returned by the command:

   "mode" : "full",
   "inBalancerRound" : false,
   "numBalancerRounds" : NumberLong(86),
   "ok" : 1
Field Description

A string that specifies whether the balancer thread is running or stopped. Possible values are:

  • “full”
    Balancer thread is running but not necessarily in a balancing round.
  • “off”
    Balancer thread is stopped. No chunk balancing can occur in this mode.
"inBalancerRound" A boolean that specifies if the balancer is currently in a balancing round; i.e. distributing chunks.
"numBalancerRounds" The number of balancer rounds which have occured since the config servers were started. This value is not persisted and is reset to 0 upon restart of the config servers.


Connect to a mongos instance and issue the following command:

db.adminCommand( { balancerStatus: 1 } )