MongoDB Installation & Getting Started

MongoDB is one of the most popular open-source document NoSQL databases. In this tutorial we will learn the following things:

  1. Installation of MongoDB
  2. Creating data directory
  3. Starting and Stopping MongoDB
  4. Running Shell Commands

Installation of MongoDB

OSX installation

We can install MongoDB on OSX (Mac OS) in two ways:

  1. Using HomeBrew Installer
  2. Manual Installation

HomeBrew Installation

Reader system should have HomeBrew Installed and brew command available on PATH.

Step 1: Update the HomeBrew Installation Package Repository

$ brew update

Step 2: Install MongoDB

(a) Install Binaries

$ brew install mongodb

(b) Install MongoDB from source with TLS/SSL support

$ brew install mongodb --with-openssl

(c) Install MongoDB edge releases (Still in development, can have bugs)

$ brew install mongodb --devel

Manual Installation

Step 1: Download Mac Binaries from the MongoDB download page.

 MongoDB Download Web Page as of 18 June 2015

You can also download the binaries using the given curl command:

curl -O https://fastdl.mongodb.org/osx/mongodb-osx-x86_64-3.0.4.tgz

You can change the MongoDB version 3.0.4 with relevant one.

Step 2: Unzip (Extract) compressed package in a folder

Unzipped MongoDB App Package

Step 3: Copy the extracted folder at some location where you wanted to keep your MongoDB and rename it to MongoDB (You are free to choose a folder name you like)

 Renamed MongoDB App Package

Step 4: MongoDB binaries executable like mongo etc should be on PATH so we can access that from any directory

Please read this tutorial for setting up the PATH on Mac OSX.

This ends the MongoDB installation.

Data storage, starting and stopping MongoDB

mongod command in bin directory is used to run the MongoDB server. mongod takes several parameters to configure the behavior of the server according to our needs.

Important: MongoDB has two different types of database storage engines.

  1. mmapv1 (default)
  2. wiredTiger

One data directory belongs to only one storage engine. If we force to use a different storage engine (–storageEngine option) for the data directory, the server will refuse to start.

$ mongod

By default data directory is /data/db/ and storage engine is mmapv1. Hence above command is equivalent to:

$ mongod --dbpath "/data/db/" --storageEngine "mmapv1"

We can change the data directory (say /data/mongodb/db/) as well as a storage engine to wiredTiger, using startup command:

$ mongod --dbpath "/data/mongodb/db/" --storageEngine "wiredTiger"



2015-06-19T11:53:05.906+0530 I JOURNAL [initandlisten] journal dir=/data/db/journal

2015-06-19T11:53:05.907+0530 I JOURNAL [initandlisten] recover : no journal files present, no recovery needed

2015-06-19T11:53:05.920+0530 I JOURNAL [durability] Durability thread started

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] MongoDB starting : pid=31488 port=27017 dbpath=/data/db 64-bit host=GEEKMJ-RT-MBP.local

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.

2015-06-19T11:53:05.920+0530 I JOURNAL [journal writer] Journal writer thread started

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten]

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten]

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] db version v3.0.3

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] git version: b40106b36eecd1b4407eb1ad1af6bc60593c6105

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] build info: Darwin bs-osx108-7 12.5.0 Darwin Kernel Version 12.5.0: Sun Sep 29 13:33:47 PDT 2013; root:xnu-2050.48.12~1/RELEASE_X86_64 x86_64 BOOST_LIB_VERSION=1_49

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] allocator: system

2015-06-19T11:53:05.920+0530 I CONTROL [initandlisten] options: {}

2015-06-19T11:53:06.008+0530 I NETWORK [initandlisten] waiting for connections on port 27017

In simple mongod command run MongoDB server with default values for all configuration options. MongoDB server is running in the foreground (interactive mode).

To stop the MongoDB server, we should press command + c, it will gracefully stop the server.

Running MongoDB server in the background (as daemon or fork) and stopping

Starting MongoDB in background as Daemon (or fork):

$ mongod --fork --logpath "/var/log/mongodb.log"

For graceful shutdown of MongoDB server (use anyone):

$ mongod --shutdown

Note: Above command only works in the Linux environment.

$ mongo

MongoDB shell version: 3.0.3

connecting to: test

> use admin

switched to db admin

> db.shutdownServer()



$ kill <mongodb-process-id>

Note Never use :

$ kill -9 <mongodb-process-id>

It terminates the MongoDB process and you may have an unexpected outcome.

mongod options

We can see all the options and sub-command available for mongod by running the command

$ mongod --help



Options:



General options:

-h [ --help ] show this usage information

--version show version information

-f [ --config ] arg configuration file specifying additional options

-v [ --verbose ] [=arg(=v)] be more verbose (include multiple times for more

verbosity e.g. -vvvvv)

--quiet quieter output

--port arg specify port number - 27017 by default

--bind_ip arg comma separated list of ip addresses to listen on

- all local ips by default

--ipv6 enable IPv6 support (disabled by default)

--maxConns arg max number of simultaneous connections - 1000000

by default

--logpath arg log file to send write to instead of stdout - has

to be a file, not directory

--syslog log to systems syslog facility instead of file

or stdout

--syslogFacility arg syslog facility used for mongodb syslog message

--logappend append to logpath instead of over-writing

--logRotate arg set the log rotation behavior (rename|reopen)

--timeStampFormat arg Desired format for timestamps in log messages.

One of ctime, iso8601-utc or iso8601-local

--pidfilepath arg full path to pidfile (if not set, no pidfile is

created)

--keyFile arg private key for cluster authentication

--setParameter arg Set a configurable parameter

--httpinterface enable http interface

--clusterAuthMode arg Authentication mode used for cluster

authentication. Alternatives are

(keyFile|sendKeyFile|sendX509|x509)

--nounixsocket disable listening on unix sockets

--unixSocketPrefix arg alternative directory for UNIX domain sockets

(defaults to /tmp)

--filePermissions arg permissions to set on UNIX domain socket file -

0700 by default

--fork fork server process

--auth run with security

--noauth run without security

--jsonp allow JSONP access via http (has security

implications)

--rest turn on simple rest api

--slowms arg (=100) value of slow for profile and console log

--profile arg 0=off 1=slow, 2=all

--cpu periodically show cpu and iowait utilization

--sysinfo print some diagnostic system information

--noIndexBuildRetry dont retry any index builds that were

interrupted by shutdown

--noscripting disable scripting engine

--notablescan do not allow table scans



Replication options:

--oplogSize arg size to use (in MB) for replication op log. default is

5% of disk space (i.e. large is good)



Master/slave options (old; use replica sets instead):

--master master mode

--slave slave mode

--source arg when slave: specify master as

--only arg when slave: specify a single database to replicate

--slavedelay arg specify delay (in seconds) to be used when applying

master ops to slave

--autoresync automatically resync if slave data is stale



Replica set options:

--replSet arg arg is [/]

--replIndexPrefetch arg specify index prefetching behavior (if secondary)

[none|_id_only|all]



Sharding options:

--configsvr declare this is a config db of a cluster; default port

27019; default dir /data/configdb

--shardsvr declare this is a shard db of a cluster; default port

27018



Storage options:

--storageEngine arg (=mmapv1) what storage engine to use

--dbpath arg directory for datafiles - defaults to /data/db

--directoryperdb each database will be stored in a separate

directory

--noprealloc disable data file preallocation - will often

hurt performance

--nssize arg (=16) .ns file size (in MB) for new databases

--quota limits each database to a certain number of

files (8 default)

--quotaFiles arg number of files allowed per db, implies --quota

--smallfiles use a smaller default file size

--syncdelay arg (=60) seconds between disk syncs (0=never, but not

recommended)

--upgrade upgrade db if needed

--repair run repair on all dbs

--repairpath arg root directory for repair files - defaults to

dbpath

--journal enable journaling

--nojournal disable journaling (journaling is on by default

for 64 bit)

--journalOptions arg journal diagnostic options

--journalCommitInterval arg how often to group/batch commit (ms)



WiredTiger options:

--wiredTigerCacheSizeGB arg maximum amount of memory to allocate

for cache; defaults to 1/2 of physical

RAM

--wiredTigerStatisticsLogDelaySecs arg (=0)

seconds to wait between each write to a

statistics file in the dbpath; 0 means

do not log statistics

--wiredTigerJournalCompressor arg (=snappy)

use a compressor for log records

[none|snappy|zlib]

--wiredTigerDirectoryForIndexes Put indexes and data in different

directories

--wiredTigerCollectionBlockCompressor arg (=snappy)

block compression algorithm for

collection data [none|snappy|zlib]

--wiredTigerIndexPrefixCompression arg (=1)

use prefix compression on row-store

leaf pages

Checking mongoDB version:

$ mongod --version

db version v3.0.3

git version: b40106b36eecd1b4407eb1ad1af6bc60593c6105

MongoDB mongod configurations in the external file

For better management of the MongoDB server, we need an external configuration file for all the options which we provide to mongod command as parameters.

A YAML format configuration file is used.

MongoDB mongod and mongos YAML based configuration same given below:

systemLog:

verbosity: 0

quiet: false

traceAllExceptions: false

syslogFacility: false

path: "/var/log/mongodb.log"

logAppend: false

#logRotate can be either "rename" or "reopen"

logRotate: "rename"

destination: "file"

timeStampFormat: "iso8601-local"

net:

bindIp: 127.0.0.1

port: 27017

maxIncomingConnections: 65536

storage:

dbPath: "/data/db"

engine" "wiredTiger"

setParameter:

enableLocalhostAuthBypass: false

...

Starting server with configuration: (Say config file is at /conf/mogodb.cnf)

$ mongod --config "conf/mongodb.cnf"

or

$ mongod -f "conf/mongodb.cnf"

Interacting with MongoDB using the mongo shell

We can connect to interactive mongo shell without any hassle if the MongoDB server is running on localhost.

$ mongo

It results in an interactive shell where we can issue commands.

MongoDB shell version: 3.0.3

connecting to: test

>

Basic mongo shell commands

1. Display the current database name

> db

test

2. Display the list of databases name

> show dbs

test

3. Switching & Creating a new database and creating a collection

There is no explicit command to create MongoDB database. It will be created when we save a document first time in a collection.

>show dbs

local 0.000GB

>use db geekmjdb

> use geekmjdb

switched to db geekmjdb

> show dbs

local 0.000GB

> db.testCollection.save ({col1:"col1val",col2:"col2val"})

WriteResult({ "nInserted" : 1 })

> db.testCollection.find()

{ "_id" : ObjectId("55845fdff7febc6f192ddcc9"), "col1" : "col1val", "col2" : "col2val" }

> show dbs

geekmjdb 0.000GB

local 0.000GB

We had seen changing database using use geekmjdb doesn’t created database. It got created when we added our first record (document) to a collection.

Collection is also created implicitly when the first document is added.

Though there is an explicit method for creating capped collection.

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