MongoDB Install and mongo shell

---

---

MongoDB 3.0

MongoDB Install and mongo shell

MongoDB Management tool : robomongo

MongoDB replication sets

MongoDB sharding

MongoDB with Python - PyMongo ...

Import the public key used by the package management system. This is because the Ubuntu package management tools (i.e. dpkg and apt) ensure package consistency and authenticity by requiring that distributors sign packages with GPG keys.

$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10

Then, we need to create the /etc/apt/sources.list.d/mongodb-org-3.0.list list file using the following command:

$ echo "deb http://repo.mongodb.org/apt/ubuntu "$(lsb_release -sc)"/mongodb-org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.0.list

Reload the local package database:

$ sudo apt-get update

Install the latest stable version of MongoDB:

$ sudo apt-get install -y mongodb-org

Before we start MongoDB for the first time, create the directory to which the mongodb process will write data. By default, the mongodb process uses the /data/db directory. If we create a directory other than this one, we must specify that directory in the dbpath option when starting the mongodb process later in this procedure:

$ sudo mkdir -p /data/db

Once the MongoDB packages are installed, we can configure username and password for the database server.

Before we set up a username and password for MongoDB, we need to open mongodb shell on your server. We can login by typing:

$ mongo

Once we're in the MongoDB shell, switch to the database named admin:

> use admin
switched to db admin

Create the root user with the following command:

> db.createUser({user:"admin", pwd:"admin", roles:[{role:"root", db:"admin"}]})
Successfully added user: {
	"user" : "admin",
	"roles" : [
		{
			"role" : "root",
			"db" : "admin"
		}
	]
}

Now, we've created user admin with password admin and have the permission/role as root and the database is admin.

The MongoDB runs using the mongodb user account. Issue the following command to start mongod:

$ sudo service mongod start

The MongoDB instance stores its data files in /var/lib/mongodb and its log files in /var/log/mongodb by default.

We can verify that the mongod process has started successfully by checking the contents of the log file at /var/log/mongodb/mongod.log for a line reading:

$ tail -2 /var/log/mongodb/mongod.log
2015-08-26T11:02:12.293-0700 I CONTROL  [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "127.0.0.1" }, storage: { dbPath: "/var/lib/mongodb" }, systemLog: { destination: "file", logAppend: true, path: "/var/log/mongodb/mongod.log" } }
2015-08-26T11:02:12.713-0700 I NETWORK  [initandlisten] waiting for connections on port 27017

Note that the default port configured in /etc/mongod.conf is 27017:

$ netstat -nlpt|grep 27017
tcp        0      0 127.0.0.1:27017         0.0.0.0:*               LISTEN      -      

Here is the summary of MongoDB at wiki:

MongoDB (from "humongous") is a cross-platform document-oriented database. Classified as a NoSQL database, MongoDB eschews the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas (BSON), making the integration of data in certain types of applications easier and faster.

1. mongod is the "Mongo Daemon". It's basically the host process for the database. When we start mongod, we're basically saying "start the MongoDB process and run it in the background". mongod has several default parameters, such as storing data in /data/db and running on port 27017.
2. mongo is the command-line shell that connects to a specific instance of mongod. When we run mongo with no parameters it defaults to connecting to the localhost on port 27017.

Collection is a group of MongoDB documents.

A collection is the equivalent of an RDBMS table.

A collection exists within a single database.

Collections do not enforce a schema. Documents within a collection can have different fields. Typically, all documents in a collection have a similar or related purpose.

When we run mongo without any arguments, the mongo shell will attempt to connect to the MongoDB instance running on the localhost interface on port 27017.

$ sudo service mongod start
mongod start/running, process 22380

$ mongo
MongoDB shell version: 3.0.6
connecting to: test
...

To see dbs:

> show dbs
local             0.078GB
mean-development  0.078GB
myFirstMB         0.203GB
rest_test         0.078GB
test              0.078GB
test-database     0.078GB
todoApp           0.078GB
todos             0.078GB

To switch current database to <test>:

> use test
switched to db test

To print a list of all collections for current database:

> show collections
system.indexes
todos

db is the variable that references the current database. The variable is automatically set to the default database test or is set when we use the use <db> to switch current database:

> db
test

To get mongodb server stats, type the command db.stats() in mongodb client. This will show the database name, number of collection and documents in the database. Output the command is shown below:

> db.stats()
{
	"db" : "test",
	"collections" : 3,
	"objects" : 7,
	"avgObjSize" : 75.42857142857143,
	"dataSize" : 528,
	"storageSize" : 20480,
	"numExtents" : 3,
	"indexes" : 1,
	"indexSize" : 8176,
	"fileSize" : 67108864,
	"nsSizeMB" : 16,
	"extentFreeList" : {
		"num" : 0,
		"totalSize" : 0
	},
	"dataFileVersion" : {
		"major" : 4,
		"minor" : 22
	},
	"ok" : 1
}

For more shell option, check mongo Shell Quick Reference

MongoDB 3.0

MongoDB Install and mongo shell

MongoDB Management tool : robomongo

MongoDB replication sets

MongoDB sharding

MongoDB with Python - PyMongo ...