MongoDB in Installation, backup and restore in Ubuntu

MongoDB Basics

MongoDB is a document oriented data base.

How to install mongoDB in ubunthu?
1. Download mongoDB 32/64bit version from http://www.mongodb.org/downloads
If you are a developer and you are going to store data less than 2GB then go for 32 bit version. Otherwise go for 64 bit version.

krishnakumar@krishnakumar:~$ uname -a

will give you the OS bit version.

32 bit:
Linux krishnakumar 3.13.0-35-generic #62-Ubuntu SMP Fri Aug 15 01:58:01 UTC 2014 i686 i686 i686 GNU/Linux

64 bit:
Linux discworld 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:50 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

Mine is 32 bit version so I have downloaded 32 bit version into downloads directory

2. Extract it into the folder.
krishnakumar@krishnakumar:~$ tar -xvf ~/Downloads/mongodb-linux-x86_64-2.6.7.tgz

Now this has been extracted and move into the directory which you wish. 

Here I am moving to Documents directory.

krishnakumar@krishnakumar:~/Downloads$ mv mongodb-linux-i686-2.6.7 ~/Documents/
krishnakumar@krishnakumar:~/Downloads$ cd ~/Documents/mongodb-linux-i686-2.6.7/bin/

We can start mongodb service by giving below command
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongod

But this command does not succeed and gives below message.

ERROR: dbpath (/data/db) does not exist.
By default all the data data files will be stored into /data/db folder but I have not created it.

So, one way to avoid this error is, just create the above folder structure

krishnakumar@krishnakumar:~/Documents/MongoDBFiles$ mkdir -p /data/db
mkdir: cannot create directory ‘/data’: Permission denied

krishnakumar@krishnakumar:~/Documents/MongoDBFiles$ sudo su root
[sudo] password for krishnakumar: 
root@krishnakumar:/home/krishnakumar/Documents/MongoDBFiles# cd
root@krishnakumar:~# mkdir -p data/db
root@krishnakumar:~# mkdir -p /data/db
root@krishnakumar:~# chmod 777 /data/db

I do not have permission to create the above mentioned folder structure, so I changed to root and created the folder and changed the folder permission. Now this starts with out error as below

krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongod

Started mongoClient
 krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongo

otherwise while starting we can provide our own path to store files as like below.
Use the parameter --dbpath
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ mongod --dbpath ~/Documents/MongoDBFiles/
By default it will point to test database and if you wish to create own database use "use" command.

Sun Jan 18 16:55:20.457 [initandlisten] 
> use student
switched to db student
> show collections
> 

I have switched to student database and try to get the collections in the student db but there is no collection exists.

I have added a student collection with some basic details as below.

> use student
switched to db student
> show collections
> db.student.save({"name":"Krishnakumar","age":"27","address":[{"Street":"1st street","city":"erode"}]}
... )
> db.student.find()
{ "_id" : ObjectId("54bb996230e9091442d80903"), "name" : "Krishnakumar", "age" : "27", "address" : [  {  "Street" : "1st street",  "city" : "erode" } ] }
> db.student.find().pretty()
{
 "_id" : ObjectId("54bb996230e9091442d80903"),
 "name" : "Krishnakumar",
 "age" : "27",
 "address" : [
  {
   "Street" : "1st street",
   "city" : "erode"
  }
 ]
}
> 

pretty() is a method which gives collection value as readable structure.

How to take backup in mongodb?
mongodump is the command used to take backup of the database.

Syntax:
mongodump --host <host name> --port <port>

Ex:
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongodump --host localhost --port 27017

connected to: localhost:27017
2015-01-18T17:36:01.483+0530 all dbs
2015-01-18T17:36:01.484+0530 DATABASE: student  to  dump/student
2015-01-18T17:36:01.485+0530  student.system.indexes to dump/student/system.indexes.bson
2015-01-18T17:36:01.485+0530    1 documents
2015-01-18T17:36:01.485+0530  student.student to dump/student/student.bson
2015-01-18T17:36:01.486+0530    1 documents
2015-01-18T17:36:01.486+0530  Metadata for student.student to dump/student/student.metadata.json
2015-01-18T17:36:01.486+0530 DATABASE: admin  to  dump/admin
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ 

We can get dump of particular collection in the db as like below.

Syntax:
mongodump --host <host name> --port <port> --collection <collection name> --db <DB>

Ex:
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongodump --host localhost --port 27017 --collection student --db student

connected to: localhost:27017
2015-01-18T17:39:01.720+0530 DATABASE: student  to  dump/student
2015-01-18T17:39:01.728+0530  student.student to dump/student/student.bson
2015-01-18T17:39:01.730+0530    1 documents
2015-01-18T17:39:01.730+0530  Metadata for student.student to dump/student/student.metadata.json
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ 

we can view the backup files in dump directory

krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ls
bsondump  mongo   mongodump    mongofiles   mongooplog  mongorestore  mongostat
dump      mongod  mongoexport  mongoimport  mongoperf   mongos        mongotop
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ cd dump/
admin/   student/

we have created student collection and after mongodump command we are able to see dump files inside student directory.
How to take a backup to the custom directory and not in default directory?

--out parameter
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin/dump/student$ ./mongodump 
--host localhost --port 27017 --collection student --db student --out ~/Documents/MongoDBFiles/

Backup for non local databases:

Syntax:
mongodump --host <host> --port <port>  --username <username> --password <password> --out /Documents/backup/mongodump

Restore dump:
mongodb dump can be restored using mongorestore command

Syntax:
mongorestore --port <port_number> <backup path>

Ex:
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongorestore --port 27017 dump/
admin/   student/ 
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ ./mongorestore --port 27017 dump/student/
connected to: 127.0.0.1:27017
2015-01-18T17:53:05.480+0530 dump/student/student.bson
2015-01-18T17:53:05.480+0530  going into namespace [student.student]
Restoring to student.student without dropping. Restored data will be inserted without raising errors; check your server log
1 objects found
2015-01-18T17:53:05.492+0530  Creating index: { key: { _id: 1 }, name: "_id_", ns: "student.student" }
krishnakumar@krishnakumar:~/Documents/mongodb-linux-i686-2.6.7/bin$ 

Restored.