When setting up:
download and untar (thats it)
/data/db or custom --dbpath (use XFS or ext4)
--directoryperdb
startup and shutdown (ctrl-c or SIGTERM)


Getting stats:
db.serverStatus()
db.stats()
db.collection.stats()
http://localhost:28017 (server port + 1000)
http://localhost:28017/_status
mongostat tool

iostat -x 2
atop

Monitoring tool plugins:
Munin ganglia nagios cacti

Code to see stats:
db.foo.drop()
for (var i=400000; i<1000000; i++){
    db.foo.insert({_id: i});
    for (var j=0; j< 10; j++){
        db.foo.findOne({_id: (i-j)});
    }
}
Run in many mongo's to boost perf. Use htop to see where time is going.
Add a big string to show disk util.

Whats going on right now?
db.currentOp()

Use this to have a query slow enough to see:
db.foo.find({$where: 'var i=1000; while(i--); return this.blah != undefined'})

Backup
mongodump / mongorestore (online-backup)
locking or shut down
backup from slave
db._adminCommand({fsync:1, lock:1})
db.$cmd.sys.unlock.findOne()

Replication (Just Do It!)
mongod --master --oplogSize 500
mongod --slave --source localhost:27017 --port 3000 --dbpath /data/slave
local.oplog.$main
seeding a slave from a master (--fastsync)
delayed replication (--slavedelay secs)
db.printReplicationInfo()
db.printSlaveReplicationInfo()

It isn't working!?!?!
check the logs
try connecting from the shell
check http output

Going into production:
distro pkgs (we have them)
init scripts (make sure they shut down cleanly)
--fork
--logpath (internal rotation)
did I mention replication?

When there's something strange
In your server room.
When you get a page
at 2am.
Who you gonna call?

ABOUT MATHIAS STEARN

Mathias Stearn is a Software Engineer at 10gen. More about Mathias Stearn