Database::MongoDB

Model.new(:my_backup, 'My Backup') do
  database MongoDB do |db|
    db.name               = "my_database_name"
    db.username           = "my_username"
    db.password           = "my_password"
    db.host               = "localhost"
    db.port               = 27017
    db.ipv6               = false
    db.only_collections   = ['only', 'these' 'collections']
    db.additional_options = []
    db.lock               = false
    db.oplog              = false
  end
end

MongoDB database dumps are created using the mongodump utility, which will output several files in a folder hierarchy like <databases>/<collections>. Backup creates this hierarchy under a directory named MongoDB. If you specified a database_id (see below), that will be appended. e.g. MongoDB-my_id.

Once the dump is complete, Backup packages this folder into a single tar archive. This archive will be in your final backup package as databases/MongoDB.tar.

If a Compressor has been added to the backup, the packaging of this folder will be piped through the selected compressor. So, if Gzip is the selected compressor, the output would be databases/MongoDB.tar.gz.

db.lock

If db.lock is set to true, Backup will issue a fsyncLock() command to force mongod to flush all pending write operations to disk and lock the entire mongod instance for the duration of the dump. Note that if you have Profiling enabled on your instance, this will be disabled (and will not be re-enabled when the dump completes).

db.oplog

If db.oplog is set to true, the --oplog option will be added to the mongodump command. This creates a database dump that includes an oplog to create a point-in-time snapshot of the current state of the mongod instance.

This is available for all nodes that maintain an oplog, including all members of a replica set, as well as master nodes in master/slave replication deployments. This is preferable over using db.lock, since the node being dumped does not need to be locked.