mongodb commands

20 commands, each with a one-line explanation. Click a command to copy it, or its title for details.

Commands 20 shown

  • Connect with mongosh
    mongosh 'mongodb://user:pass@mongo:27017/dbname'

    Open interactive shell to a MongoDB instance

  • Replica set status
    mongosh --eval 'rs.status()' mongodb://mongo:27017

    Show replica set members, lag, and election status

    monitoring

  • Database stats
    mongosh --eval 'db.stats()' mongodb://mongo:27017/mydb

    Data size, storage size, collection count for a database

    monitoring

  • Collection stats
    mongosh --eval 'db.myCollection.stats()' mongodb://mongo:27017/mydb

    Document count, index sizes, storage for a collection

  • Current operations
    mongosh --eval 'db.currentOp({active:true,secs_running:{$gt:5}})' mongodb://mongo:27017

    Show operations running longer than 5 seconds

    debug · monitoring

  • Create dump
    mongodump --uri='mongodb://user:pass@mongo:27017' --db=mydb --out=/backups/

    Export database to BSON files

  • Restore dump
    mongorestore --uri='mongodb://user:pass@mongo:27017' --db=mydb /backups/mydb/

    Import BSON backup into MongoDB

  • List indexes
    mongosh --eval 'db.myCollection.getIndexes()' mongodb://mongo:27017/mydb

    Show all indexes on a collection

  • Connect with URI
    mongosh 'mongodb+srv://user:pass@cluster.example.com/mydb'

    Connect to Atlas or any MongoDB URI with mongosh

  • Explain query plan
    db.orders.find({status:'new'}).explain('executionStats')

    Show execution stats including index usage

    debug

  • Create compound index
    db.orders.createIndex({userId: 1, createdAt: -1}, {background: true})

    Ascending userId + descending createdAt index

  • Aggregation pipeline example
    db.orders.aggregate([{$match:{status:'paid'}},{$group:{_id:'$userId',total:{$sum:'$amount'}}},{$sort:{total:-1}},{$limit:10}])

    Top 10 users by paid order amount

  • Check replication lag
    rs.printSecondaryReplicationInfo()

    Show secondary lag and oplog window

    monitoring

  • Current operations (slow queries)
    db.currentOp({active:true, secs_running:{$gt:5}})

    List operations running longer than 5 seconds

    debug

  • Dump a database
    mongodump --uri='mongodb://localhost:27017' --db=mydb --out=/backup/$(date +%F)

    Dump all collections in a database to BSON files

  • Replica set status
    mongosh --eval 'rs.status().members.forEach(m=>print(m.name,m.stateStr,m.optimeDate))'

    Per-member state and last applied optime; spot lagging or unhealthy secondaries

    monitoring · troubleshooting · observability

  • Kill long-running ops
    mongosh --eval 'db.currentOp({secs_running:{$gt:5},op:{$ne:"none"}}).inprog.forEach(o=>{print(o.opid,o.secs_running,o.ns); db.killOp(o.opid)})'

    List queries running >5s with ns then killOp each; note: killOp is async, verify after

    troubleshooting · performance · debug

  • Query plan with stats
    mongosh --eval 'db.<name>.find({status:"active"}).explain("executionStats").executionStats'

    Show docs examined vs returned and index usage; COLLSCAN means missing index

    performance · troubleshooting · debug

  • Unused index detection
    mongosh --eval 'db.<name>.aggregate([{$indexStats:{}}]).forEach(i=>print(i.name,i.accesses.ops))'

    Access count per index; zero ops = candidate to drop and reclaim write cost

    performance · disk · monitoring

  • Profile slow queries
    mongosh --eval 'db.setProfilingLevel(1,{slowms:100}); db.system.profile.find().sort({millis:-1}).limit(5)'

    Capture ops slower than 100ms then read top offenders from system.profile

    performance · troubleshooting · observability