Want to Find Slow Queries? Check MongoDB Current Operations

currentOp is a MongoDB admin command that returns a document with information on operations in progress.

Studio 3T replaces the currentOp command with a Current Operations feature, which you can access by right-clicking on any collection in the Connection Tree.

This opens a new Current Operations tab which displays data for in-progress and expired ops – if you so choose.

Find a slow MongoDB query

An effective way of spotting slow MongoDB queries is to check the Show Only Slow Ops box.

You can define what “slow” is by choosing one of four default settings: 1, 3, 10 or 30 seconds. The queries that meet this criteria will appear as results – think of it as your collection’s slow query log.

Kill long-running operations

Once you’ve identified your slow MongoDB queries, choose the operation(s) you want to cancel from the results. Then, click on the Kill operation button.

Show expired ops

In addition to current operations, you can also choose to show expired operations by checking the Retain Expired Ops box. Expired operations will appear greyed out.

You can retain all expired operations or only those executed in the last 10 seconds, 30 seconds, 1, 2, 5, or 10 minutes.

Show own ops only

If there are multiple current operations running against your collection and you only want to show those you’ve started, check on the Show own ops only box.

Show system operations

To show system operations alongside user operations, check the Show Sys Ops box.

Change update frequency

You can also decide how often to refresh current operations:

Filter current operations

To filter only a certain type of operation, click on the corresponding icon. From left to right, the options are:

• n – none
• u – update
• i – insert
• q – query
• g – getmore
• r – remove
• k – killcursors

MongoDB current operations

The Current Operations feature in Studio 3T displays this data for all operation types:

• opid
• expired
• host
• desc
• connectionId
• client
• clientMetadata
• active
• currentOpTime
• secs_running
• microsecs_running
• op
• ns
• command
• planSummary
• numYields
• locks
• waitingForLock
• lockStats

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