MongoDB Installation & Getting Started

Learn how to install, setup and running MongoDB database. You can also learn to interact with MongoDB shell mongo.

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

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

mongodb logo

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 bug)

$ brew install mongodb --devel

Manual Installation

Step 1: Download Mac Binaries from mongoDB download page.

MongoDB Download Web Page ScreenShot MongoDB Download Web Page as on 18 June 2015

You can also download the binaries using given curl command:

curl -O

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 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 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 use to run the mongoDB server. mongod takes several parameters to configure the behaviour of server according to our need.

Important: MongoDB have two different types of database storage engine.

  1. mmapv1 (default)
  2. wiredTiger

One data directory belong to only one storage engine. If we force to use different storage engine (–storageEngine option) for data directory, 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 data directory (say /data/mongodb/db/) as well as 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 on foreground (interactive mode).

For stopping the mongoDB server, we should press command + c, it will gracefully stopped the server.

Running mongoDB server in 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 on 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 can have unexpected outcome.

mongod options

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

$ mongod --help


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
  --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
  --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
  --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)

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

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
  --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
  --upgrade                     upgrade db if needed
  --repair                      run repair on all dbs
  --repairpath arg              root directory for repair files - defaults to
  --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
  --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
  --wiredTigerDirectoryForIndexes       Put indexes and data in different
  --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 external file

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

An YAML format configuration file is used.

MongoDB mongod and mongos YAML based configuration same given below:

   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"
   port: 27017
   maxIncomingConnections: 65536
   dbPath: "/data/db"
   engine" "wiredTiger"
   enableLocalhostAuthBypass: false

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

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


$ mongod -f "conf/mongodb.cnf"

Interacting with MongoDB using mongo shell

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

$ mongo

It result in an interactive sheel 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

2. Display the list of databases name

\> show dbs

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
> ({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 get created when we had added our first record (document) in a collection.

Collection also created implicitly when first document is added.

Though there is an explicit method for creating capped collection.

Mrityunjay Kumar
Mrityunjay Kumar
Principal Architect

My interests include software architecture, cloud computing, data & Artificial Intelligence.

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