Cassandra Get Started

Cassandra

Cassandra is NoSQL, and original is provided by Facebook.

It is to handle huge data for application use.

Why Cassandra?

Our company provides Web Application which uses MySQL(lack of connections)

Users are increasing and difficult to support only single master <-> slave structure.

We want to switch scalable data sources to resolve this situation.

Of course, there are several solutions in MySQL

Sharding by code
Clustrix
Scale up

Scale up is not exact solution. First 2 are kind of distribution techniques. Finally MySQL solution is not easy to do it, and Cassandra is suitable for our case, so we decided to use cassandra.

The good thing of cassandra is scalable. Add more servers, and can support more traffic from users.

Test on local machine

I use Mac mini for Test

Download Cassandra binary on local machine
Single Node

Install Cassandra

In this time, I just download binary from Cassandra website and decompress

Not install

Start cassandra

Go to cassandra directly and go bin directly

./cassandra -f

-f is foreground mode. Without -f, cassandra runs as daemon. (Cannot stop from command) If you can stop cassandra, just Ctrl+C

Cassandra uses 9042 and 7199 port.

cqlsh

cqlsh is simple Cassandra client. Use this and can connect cassandra

./cqlsh

Now, you can enter CQL Shell

Let’s try

In this time, I tried

Create Keyspace
Create table under keyspace
Insert data
Select data

It’s like MySQL.

MySQL	Cassandra
Database	Keyspace
Table	Table

The keyspace is database of MySQL.

Create Keyspace

CREATE KEYSPACE test WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor': 1};

Move test keyspace

Use test;

Create table

CREATE TABLE users (
     id int PRIMARY KEY,
    name text
);

Insert record

INSERT INTO users (id, name) VALUES (1, 'Bob');

Retrieve data

SELECT * FROM users;

Other commands

Show all keyspaces

DESCRIBE KEYSPACES;

Show all tables

DESCRIBE TABLES;

Show specific table details

 DESCRIBE TABLE users;