dropConnections¶

On this page

Access Control
Behavior
Example

dropConnections¶

New in version 4.2.

The dropConnections command drops the mongod/mongos instance’s outgoing connections to the specified hosts. The dropConnections must be run against the admin database.

The command has following syntax:

copy

db.adminCommand({
  dropConnections: 1,
  hostAndPort : [ "host1:port1", "host2:port2", ... ],
  comment: <any>
})

The command requires the following field:

Field Type Description

hostAndPort array Each array element represents the hostname and port of a remote machine.

comment

any

Optional. A user-provided comment to attach to this command. Once set, this comment appears alongside records of this command in the following locations:

mongod log messages, in the attr.command.cursor.comment field.
Database profiler output, in the command.comment field.
currentOp output, in the command.comment field.

A comment can be any valid BSON type (string, integer, object, array, etc).

New in version 4.4.

Access Control¶

If the deployment enforces authentication/authorization, the dropConnections command requires the dropConnections action on the cluster resource.

Create a user-defined role in the admin database where the privilege array includes the following document:

copy

{ "resource" : { "cluster" : true } }, "actions" : [ "dropConnections" ] }

Use db.createUser() to create a user on the admin database with the custom role.

or
Use db.grantRolesToUser() to grant the role to an existing user on the admin database.

For example, the following operation creates a user-defined role on the admin database with the privileges to support dropConnections:

copy

db.getSiblingDB("admin").createRole(
  {
    "role" : "dropConnectionsRole",
    "privileges" : [
      {
        "resource" : { "cluster" : true },
        "actions" : [ "dropConnections" ]
      }
    ],
    "roles" : []
  }
)

Assign the custom role to a user on the admin database:

copy

db.getSiblingDB("admin").createUser(
  {
    "user" : "dropConnectionsUser",
    "pwd" : "replaceThisWithASecurePassword",
    "roles" : [ "dropConnectionsRole" ]
  }
)

The created user can execute dropConnections.

For more examples of user creation, see Add Users. For a tutorial on adding privileges to an existing database user, see Modify Access for an Existing User.

Behavior¶

dropConnections silently ignores hostAndPort elements that do not include both the hostname and port of the remote machine.

Example¶

Consider a replica set with a recently removed member at oldhost.example.com:27017. Running the following dropConnections command against each active replica set member ensures there are no remaining outgoing connections to oldhost.example.com:27017:

copy

db.adminCommand(
  {
    "dropConnections" : 1,
    "hostAndPort" : [
      "oldhost.example.com:27017"
    ]
  }
)

The command returns output similar to the following:

copy

{
 "ok" : 1,
 "$clusterTime" : {
   "clusterTime" : Timestamp(1551375968, 1),
   "signature" : {
     "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
     "keyId" : NumberLong(0)
   }
 },
 "operationTime" : Timestamp(1551375968, 1)
}

You can confirm the status of the connection pool for the mongod or mongos using the connPoolStats command.

← dropDatabase dropIndexes →