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db.killOp()

Description

db.killOp(opid)

Terminates an operation as specified by the operation ID. To find operations and their corresponding IDs, see $currentOp or db.currentOp().

The db.killOp() method has the following parameter:

Parameter Type Description
op number An operation ID.

Warning

Terminate running operations with extreme caution. Only use db.killOp() to terminate operations initiated by clients and do not terminate internal database operations.

Sharded Cluster

Kill Read Operations

Starting in MongoDB 4.0

The db.killOp() method can be run on a mongos and can kill queries (read operations) that are running on more than one shard in a cluster.

For example, to kill a query operation on a MongoDB 4.0+ sharded cluster:

  1. On the same mongos where the client issued the query, find the opid of the query operation to kill by running the aggregation pipeline $currentOp with the localOps: true:

    use admin
    db.aggregate( [
       { $currentOp : { allUsers: true, localOps: true } },
       { $match : <filter condition> } // Optional.  Specify the condition to find the op.
                                       // e.g. { op: "getmore", "command.collection": "someCollection" }
    ] )
    

    Important

    You must issue this aggregation operation on the same mongos where the client issued the query.

  2. Once you find the query operation to kill, issue db.killOp() with the opid on the mongos:

    db.killOp(<opid of the query to kill>)
    

See also

The localOps parameter in $currentOp.

Alternatively, you can find and kill the read operation from a shard member where the operation is running. MongoDB 4.0+ propagates the kill operation to the other shards and mongos instances:

  1. On one of the shards where the operation is running, find the opid of the query operation to kill:

    use admin
    db.aggregate( [
       { $currentOp : { allUsers: true } },
       { $match : <filter condition> } // Optional.  Specify the condition to find the op.
                                        // e.g. { op: "getmore", "command.collection": "someCollection" }
    ] )
    
  2. Once you find the query operation to kill, issue db.killOp() with the opid on the shard member:

    db.killOp(<opid of the query to kill>)
    

    MongoDB 4.0+ propagates the kill operation to the other shards and mongos instances.

For MongoDB 3.6 and earlier

To kill a query running on 3.6 (or earlier) sharded clusters, you must kill the operation on all the shards associated with the query.

  1. From a mongos, run the aggregation pipeline $currentOp to find the opid(s) of the query operation on the shards:

    use admin
    db.aggregate( [
       { $currentOp : { allUsers: true } },
       { $match : <filter condition> } // Optional.  Specify the condition to find the op.
                                       // e.g. { op: "getmore", "command.collection": "someCollection" }
    ] )
    

    When run on a mongos, $currentOp returns the opids in the format of "<shardName>:<opid on that shard>"; e.g.

    {
       "shard" : "shardB",
       ..
       "opid" : "shardB:79014",
       ...
    },
    {
       "shard" : "shardA",
       ..
       "opid" : "shardA:100813",
       ...
    },
    
  2. Using the opid information, issue db.killOp() on the mongos to kill the operation on the shards.

    db.killOp("shardB:79014");
    db.killOp("shardA:100813");
    

Kill Write Operations

Within a Session

Starting in MongoDB 3.6, MongoDB drivers associate all operations with a server session, with the exception of unacknowledged writes.

If the write operation is associated with a session, you can use the killSessions command on the mongos to kill the write operation across shards.

  1. Run the aggregation pipeline $currentOp on the mongos to find the lsid (logical session id).

    use admin
    db.aggregate( [
       { $currentOp : { allUsers: true, localOps: true } },
       { $match : <filter condition> } // Optional.  Specify the condition to find the op.
                                        // e.g. { "op" : "update", "ns": "mydb.someCollection" }
    ] )
    
  2. Using the returned lsid information, issue the killSessions command on the mongos to kill the operation on the shards.

    db.adminCommand( { killSessions: [
       { "id" : UUID("80e48c5a-f7fb-4541-8ac0-9e3a1ed224a4"), "uid" : BinData(0,"47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=") }
    ] } )
    
  1. Run the aggregation pipeline $currentOp on the mongos or the individual shards find the lsid (logical session id).

    use admin
    db.aggregate( [
       { $currentOp : { allUsers: true } },
       { $match : <filter condition> } // Optional.  Specify the condition to find the op.
                                        // e.g. { "op" : "update", "ns": "mydb.someCollection" }
    ] )
    
  2. Using the returned lsid information, issue the killSessions command on the mongos to kill the operation on the shards.

    db.adminCommand( { killSessions: [
       { "id" : UUID("80e48c5a-f7fb-4541-8ac0-9e3a1ed224a4"), "uid" : BinData(0,"47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=") }
    ] } )
    
Without a Session

If the write operation is not associated with a session, you must find and kill the operation on all the shards associated with the write.

  1. From a mongos, run the aggregation pipeline $currentOp to find the opid(s) of the query operation on the shards:

    use admin
    db.aggregate( [
       { $currentOp : { allUsers: true } },
       { $match : <filter condition> } // Optional.  Specify the condition to find the op.
    ] )
    

    When run on a mongos, $currentOp returns the opids in the format of "<shardName>:<opid on that shard>"; e.g.

    {
       "shard" : "shardB",
       ..
       "opid" : "shardB:79214",
       ...
    },
    {
       "shard" : "shardA",
       ..
       "opid" : "shardA:100913",
       ...
    },
    
  2. Using the opid information, issue db.killOp() on the mongos to kill the operation on the shards.

    db.killOp("shardB:79014");
    db.killOp("shardA:100813");
    

Access Control

On systems running with authorization, to kill operations not owned by the user, the user must have access that includes the killop privilege action.

Changed in version 3.2.9: On mongod instances, users can kill their own operations even without the killop privilege action.

See also

$currentOp