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db.currentOp()

db.currentOp()

Returns a document that contains information on in-progress operations for the database instance. The db.currentOp() method wraps the database command currentOp.

Note

Because currentOp command and db.currentOp() helper returns the results in a single document, the total size of the currentOp result set is subject to the maximum 16MB BSON size limit for documents.

Starting in version 3.6, MongoDB provides $currentOp aggregation stage. The $currentOp stage returns a cursor over a stream of documents, each of which reports a single operation. Each operation document is subject to the 16MB BSON limit, but unlike the currentOp command, there is no limit on the overall size of the result set.

For this reason, the $currentOp aggregation stage is preferred over the currentOp command and its mongo shell helper db.currentOp().

db.currentOp() has the following form:

db.currentOp(<operations>)

db.currentOp() can take the following optional argument:

Parameter
Type
Description
boolean or document

Optional. Specifies the operations to report on. Can pass either a boolean or a document:

  • Specify true to include operations on idle connections and system operations.
  • Specify a document with query conditions to report only on those operations that match the conditions. See Behavior for details.

db.currentOp() can accept a filter document or a boolean parameter.

If you pass a filter document to db.currentOp(), the output returns information only for the current operations that match the filter. The filter document can contain:

Field
Description
"$ownOps"

Boolean. If set to true, returns information on the current user's operations only.

On mongod instances, users can always run db.currentOp( { "$ownOps": true } ) to view their own operations.

New in version 3.2.9.

"$all"

Boolean. If set to true, returns information on all operations, including operations on idle connections and system operations.

If the document includes "$all": true along with Output Fields conditions, only the "$all":true applies.

<filter>

Specify filter conditions on the Output Fields. See Examples.

If the document includes "$all": true along with Output Fields conditions, only the "$all": true applies.

Passing in true to db.currentOp() is equivalent to passing in a document of { "$all": true }. The following operations are equivalent:

db.currentOp(true)
db.currentOp( { "$all": true } )

db.currentOp() and the database profiler report the same basic diagnostic information for all CRUD operations, including the following:

These operations are also included in the logging of slow queries (see slowOpThresholdMs for more information about slow query logging).

On systems running with authorization, the user must have access that includes the inprog privilege action.

Starting in 3.2.9, users can run db.currentOp( { "$ownOps": true } ) on mongod instances to view their own operations even without the inprog privilege action.

Tip
See also:

The following examples use the db.currentOp() method with various query documents to filter the output.

Changed in version 3.6.

The following example returns information on all write operations that are waiting for a lock:

db.currentOp(
{
"waitingForLock" : true,
$or: [
{ "op" : { "$in" : [ "insert", "update", "remove" ] } },
{ "command.findandmodify": { $exists: true } }
]
}
)

The following example returns information on all active running operations that have never yielded:

db.currentOp(
{
"active" : true,
"numYields" : 0,
"waitingForLock" : false
}
)

The following example returns information on all active operations for database db1 that have been running longer than 3 seconds:

db.currentOp(
{
"active" : true,
"secs_running" : { "$gt" : 3 },
"ns" : /^db1\./
}
)

Changed in version 3.6.

The following example returns information on index creation operations:

db.adminCommand(
{
currentOp: true,
$or: [
{ op: "command", "command.createIndexes": { $exists: true } },
{ op: "none", "msg" : /^Index Build/ }
]
}
)

The following is a prototype of db.currentOp() output.

For a complete list of db.currentOp() output fields, see currentOp.

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On this page

  • Definition
  • Behavior
  • Access Control
  • Examples
  • Output Example
  • Output Fields