DEV meet-up UiPath Document Understanding May 7 2024 Amsterdam
Apache cassandra
1. By: Muralidharan Deenathayalan
Technical Lead, www.quanticate.com
Apache, Apache Cassandra, and Cassandra are trademarks of the Apache Software Foundation. Terms & Conditions
2. My Bio data
• 7+ years of experience in Microsoft technologies like Asp.net, C#, SQL server and SharePoint
• 2+ years of experience in open source technologies like Java, Alfresco and Apache Cassandra
• Csharpcorner MVP
Why I love Cassandra
• It runs on Windows machines
• Easy to install
• Easy to configure
• Easy to develop
3. Agenda
• What is Apache Cassandra ?
• Birth
• Architecture
• Key Features
• Key Components
• Apache Cassandra Connectivity
• What is CQL and CQL Drivers
• Apache Cassandra – CRUD Demo
4. What is Apache Cassandra
• Distributed
• High Performance
• Scalable
• No Single Point of Failure database
6. Apache Cassandra - Architecture
• The ring represents a cyclic range of
token values (i.e., the token space).
• Each node is assigned a position on the
ring based on its token.
• Each node communicates with each
other node using Gossip protocol.
• First data written into commit log for
data durability
• Later data pushed from commit log to
memtable, once memtable is full then
the data written into sstable (disk).
8. Apache Cassandra – Key Components
Keyword Description
Schema / Keyspace A collection of column families
Table/ Column Family A set of rows
Row An ordered set of columns
Partitioning Keys are mapped into the token space by a Partitioner.
Replication Cassandra provides high availability and fault tolerance
through data replication. The replication uses the ring to
determine nodes used for replication.
Consistency Levels Clients can specify the consistency level on both read and
write operations trading off between high availability,
consistency, and perform
CQL Cassandra provides an SQL-like query language called the
Cassandra Query Language
9. Apache Cassandra connectivity
• Apache Thrift (RPC)
• Scalable cross-language services development
• C++, Java, Python, PHP, Ruby, Erlang, Perl, Haskell, C#, Cocoa, JavaScript, Node.js,
Smalltalk, OCaml and Delphi
• thrift --gen <language> <Thrift filename>
• http://thrift.apache.org/
• Cassandra Query Language (CQL)
• SQL like statements
• Supports Triggers
• Does not support Sub-queries and joins
• http://www.datastax.com/documentation/cql/3.1/cql/cql_using/about_cql_c.html
10. Apache Cassandra - CQL Client Drivers
Language /
Framework
Client driver
Name
Description URI
PHP Cassandra -
PDO
A CQL (Cassandra Query
Language) driver for PHP
http://code.google.com/a/apache-
/
Python Pycassa Pycassa is the most well
known Python library for
Cassandra
https://
github.com/pycassa/pycassa
Ruby Ruby Gem Ruby has support for
Cassandra via a gem.
http://
rubygems.org/gems/cassandra
.NET Cassandra-
Sharp
.NET client for Cassandra https://
github.com/datastax/csharp
-driver
Node.Js Cassandra-
Node
Cassandra/ CQL driver
for Node.js
https://github.com/racker/node-ca
11. Step 1: Install Apache Cassandra.
http://cassandra.apache.org/download/
Step 2: Install Python.
http://www.python.org/download/releases/2.7.3/
Step 3: Add the Python executable path in the windows path variable,
otherwise configure in the environment variable.
Open command prompt :
C:> path =%path%;<python exe path>
Step 4: In the command prompt, navigate to Cassandrabin folder.
For ex C:cassandrabin>
Apache Cassandra - Installation
12. Apache Cassandra – Starting CLI
Step 1:
Start the Apache Cassandra Server by running <Cassandra>binCassandra.bat.
Step 2:
Start Command Line Interface from <Cassandra>bincassandra-cli.bat
Step 3:
Connect you Cassandra CLI with Cassandra Server..
Command: connect localhost/9160;
13. Apache Cassandra – Using CLI
Demo
Connect Cassandra Server - connect localhost/9160;
Displaying existing Keyspaces - show keyspaces;
Creating new keyspace - CREATE KEYSPACE testkeyspace with
placement_strategy = 'org.apache.cassandra.locator.SimpleStrategy'
and strategy_options = {replication_factor:1};
Use existing keyspace - use testkeyspace ;
Creating column family - create column family users with comparator =
UTF8Type and key_validation_class=UTF8Type and column_metadata =
[{column_name: userName, validation_class:UTF8Type}, {column_name:
email, validation_class:UTF8Type}];
14. Apache Cassandra – Using CLI
Demo
Insert records into Columnfamily
- set users['student01']['userName']='Student1';
- set users['student01']['email']='Student1@example.com';
Read existing record in a Columnfamily
- get users['student01']['userName'];
- get users['student01'];
Update records in Columnfamily
- set users['student01']['email']='Student1@example.co.in';
Deleting records in Columnfamily
- del users['student01']['email'];
- del users['student01'];
15. Apache Cassandra – Using CQL
Demo
Connect Cassandra Server and execute CQLSh.bat file
Create Keyspace
- CREATE KEYSPACE CassandraCQLDemo
WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 3 };
Use existing keyspace
- use CassandraCQLDemo;
Creating tables
- CREATE TABLE users( user_id varchar, age int, email varchar, city
varchar,PRIMARY KEY (user_id));
16. Apache Cassandra – Using CQL
Demo
Insert records into table
- INSERT INTO users(user_id, age, email, city)VALUES
('jsmith',32,'john.smith@example.com','Dallas');
- INSERT INTO users(user_id, city) VALUES ('pscott','New Jersey');
Read records from table
- SELECT * FROM users;
- SELECT * FROM users WHERE user_id='jsmith';
Update existing record in a table
- update users set email = ‘muralidharan@example.com’ where
user_id=‘'jsmith’;
Deleting records in table
- DELETE email FROM users WHERE user_id = 'jsmith ';
- DELETE FROM users WHERE user_id = 'pscott';
