Cassandra Database : The Next Big Thing

Apache Cassandra, a top level Apache project born at Facebook , is a distributed database for managing large amounts of structured data across many commodity servers, while providing highly available service and no single point of failure.




In a terminal window:

1. Check which version of Java is installed by running the following command:

$ java -version

It is recommended to use the latest version of Oracle Java 8 or OpenJDK 8 on all nodes.
2. Download Apache Cassandra 3.0:

$ curl -L | tar xz

To view the available versions, see the DataStax Certified Cassandra download page.

3. If you download from this page, use the following command to untar:

$ tar -xvzf dsc-cassandra-version_number-bin.tar.gz

4. To configure Cassandra, go to the install/conf directory:

$ cd dsc-cassandra-version_number/conf

Additional Information :

In Ubuntu 16.x , while Running Cql ,  If an error like this pops : 

//ERROR   :  Connection error: (‘Unable to connect to any servers’, {‘’: TypeError(‘ref() does not take keyword arguments’,)})

Use these commands And try again : 

$ sudo apt-get install python-pip

$ pip install cassandra-driver

$ export CQLSH_NO_BUNDLED=true

Accessing the Cassandra Database

The Cassandra Database Can be Queried By multiple Ways.We will discuss 2 Major ways :

  1. Directly through Cql terminal.
  2. Through a Scala Program. 

In both cases we first need to run the Cassandra by going to the directory through the terminal where Cassandra is installed With the help of cd command : 

$ cd install_location (path of the cassandra directory)

After that use the following command to start the Cassandra :

$ ./bin/cassandra   ( use -f  for running Cassandra in foreground)

Once the Cassandra is up and running We can now move to using it. Let us discuss the 2 ways we named earlier to use the Cassandra database :

Using Cassandra Through Cqlsh (CQL terminal)

Go to the directory through the terminal where Cassandra is installed with the help of cd command : 

$ cd install_location (path of the cassandra directory)

Use the command to run the cql Terminal 

$ ./bin/cqlsh

You will See Something like this : 

Connected to Test Cluster at
[cqlsh 5.0.1 | Cassandra 2.2.7 | CQL spec 3.3.1 | Native protocol v4]
Use HELP for help.
cqlsh>  // Start Here

After Getting this Screen You are ready to Go.


  • To Begin With We First Need a Keyspace : 


Example : CREATE KEYSPACE Demo WITH replication = {‘class’:’SimpleStrategy’, ‘replication_factor’ : 1}; 

  • Using the Keyspace : 

Command : USE

Example : USE  Demo ; 

  • NOTE : To List the available Keyspaces Use : 


  • Deleting a Keyspace :


Example :DROP KEYSPACE Demo;


  • To Create a Table :

Command :  CREATE TABLE  (column1_name datatype,column2_name data type,column3_name data type,….,PRIMARY KEY(,)) 

Example :  CREATE TABLE employee(emp_id int, emp_name text,emp_city text,emp_salary varint,emp_phone varint,PRIMARY KEY(emp_id,emp_salary));

  • Inserting Data into the Table : 

Command : INSERT INTO (coloumns) VALUES (values)

Example :    INSERT INTO employee(emp_id, emp_name,emp_city ,emp_salary ,emp_phone) VALUES(1,’Name1′,’Delhi’,50000,9876543210);

  • NOTE : To List the available Tables :


  • Updating a table : 

Command : ALTER TABLE  

Example 1 (Add Column) : ALTER TABLE employee ADD emp_email text;

Example 1 (Drop Column) : ALTER TABLE employee DROP emp_email;

  • Deleting a Table :

Command : DROP TABLE 

Example :DROP TABLE employee;

  • Querying The Tables :


Example : Select * from employee where emp_id=1 ;

Using Cassandra Through Scala Program

Note : Make Sure the Cassandra is Running

1. Create a new Sbt Project.

2. Add the following dependency in built.sbt :

libraryDependencies += “com.datastax.cassandra” % “cassandra-driver-core” %”″

3. Import the following in the Program :

import com.datastax.driver.core.Cluster

4. Within the Object create the following : 

// creating Cluster object
val cluster = Cluster.builder().addContactPoint(“localhost”).build()

// Creating Session object
val session = cluster.connect()

5. Create  a normal query in a variable  and execute the query : 

val createKeySpaceQuery = "CREATE KEYSPACE cassandraDemo WITH replication = {'class':'SimpleStrategy', 'replication_factor':1};"

6. Similarly Execute all the queries.

For Other Important Commands. Refer this Link to Datastax site:

For Further Reference Check out the Github Link:

This entry was posted in Scala and tagged , . Bookmark the permalink.

3 Responses to Cassandra Database : The Next Big Thing

  1. Bharat Singh says:

    Reblogged this on Bharat Singh and commented:

    Cassandra Usage – Basics

  2. anmolsarna09 says:

    Reblogged this on Site Title and commented:
    Cassandra Database : The Next Big Thing

  3. Pingback: Cassandra Writes: A Mystery? | Knoldus

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