MongoDB vs HBase

First, you need to make sure of your windows version.

2)Once you have downloaded you can extract the folder mongodb-win32-i386-[version] or mongodb-win32-x86_64-[version].

3)Go to command prompt and run below command:

     C:\>move mongodb-win64-* mongodb                                                        1 dir(s) moved. The default location for this folder should be C:\data\db.

4)Now go to the bin directory in MongoDB installation folder and set the path as below:

C:\Users\XYZ>d:

D:\>cd “set up”

D:\set up>cd mongodb

D:\set up\mongodb>cd bin

D:\set up\mongodb\bin>mongod.exe –dbpath “d:\set up\mongodb\data”

5)      Install MongoDB and install it using :

apt-get install mongodb-10gen = 2.2.3 and start MongoDB using:

sudo service mongodb start

1)Create a user using the below commands:

$su

Password:

#useradd Hadoop

#passwd Hadoop

New passwd:

Retype new passwd

2)The next step involves ssh setup and key generation. Following commands can help you to generate a key-value pair using ssh.

$ ssh-keygen –t rsa

$ cat ~/. ssh/id_rsa.pub >> ~/.ssh/authorized_keys

$ chmod 0600 ~/.ssh/authorized_keys

3)      Installing JAVA includes a Java version of jdk-7u71-Linux-x64.tar.gz. Extract this and move it to /usr/local. Once this is done set the path and JAVA_HOME variables in ~/.bashrc profile.

4)      Set up Hadoop environment by configuring all files like hdfs-site.xml, yarn-site.xml, core-site.xml, mapred-site.xml

5)      Setup Hbase in standalone mode by configuring hbase—nv.sh and hbase-site.xml files. You can also install it in Pseudo mode by configuring hbase-site.xml file.

Syntax:

db.createCollection(name, options)

Name: Name of the collection which needs to be created

Options: This is an optional field and specifies memory size and indexing.

The optional field can have below options:

1)Capped: It enables capped collection which has the capability to automatically overwrite the fixed size and the old entries once a maximum size is reached.

2)autoIndexId: It creates an index automatically

3)size: It specifies maximum bytes for capped collection.

4)Max: It ensures a maximum number of documents allowed.

Example:

>use test

switched to db test

>db.createCollection(“mycollection”)

{ “ok” : 1 }

These can be checked using:

>show collections

mycollection

system.indexes

Syntax:

create ‘table name’, ’column family’

Example:

hbase(main):002:0> create ’emp’, ‘personal data’, ‘professional data’

A table can also be created using JAVA API. The steps to create it can be as:

1)      Instantiate HBaseAdmin

This requires configuration as a parameter which will instantiate the respective configuration class and pass it to HBaseAdmin.

Configuration conf = HBaseConfiguration.create();

HBaseAdmin admin = new HBaseAdmin(conf);

2)      Next the user can create TableDescriptor. HTableDescriptor is the class that will contain table names and column families.

//creating table descriptor

HTableDescriptor newtable = new HTableDescriptor(toBytes(“Table name”));

//creating column family descriptor

HColumnDescriptor newfamily = new HColumnDescriptor(toBytes(“column family”));

//adding coloumn family to HTable

table.addFamily(newfamily);

3)      Execute through Admin: Using createTable() method we can execute the method present in HBaseAdmin using:

admin.createTable(table);

Syntax:

db.collection_name.drop()

hbase(main):018:0> disable ’emp’

0 row(s) in 1.4580 seconds

Once a table is disabled you can delete the table by using the below commands:

hbase(main):019:0> drop ’emp’

0 row(s) in 0.3060 seconds

Using regex you can delete multiple tables as well.