Skip to content

hemangajmera/cassandra

This branch is 4370 commits behind apache/cassandra:trunk.

Folders and files

NameName
Last commit message
Last commit date

Latest commit

4e5bd27 · Apr 20, 2021
Apr 19, 2021
Apr 19, 2021
Feb 10, 2021
Mar 16, 2021
Apr 19, 2021
Apr 2, 2021
Apr 19, 2021
Aug 24, 2017
Apr 8, 2021
Apr 16, 2021
Apr 19, 2021
Apr 19, 2021
Apr 20, 2021
Apr 20, 2021
Mar 26, 2021
Apr 19, 2021
Feb 10, 2018
Apr 20, 2021
Apr 19, 2021
Mar 31, 2021
Mar 17, 2021
Mar 31, 2021
Feb 26, 2021
Apr 19, 2021
Apr 19, 2021
May 21, 2019
Apr 19, 2021
May 27, 2015
Apr 19, 2021

Repository files navigation

Apache Cassandra

Apache Cassandra is a highly-scalable partitioned row store. Rows are organized into tables with a required primary key.

Partitioning means that Cassandra can distribute your data across multiple machines in an application-transparent matter. Cassandra will automatically repartition as machines are added and removed from the cluster.

Row store means that like relational databases, Cassandra organizes data by rows and columns. The Cassandra Query Language (CQL) is a close relative of SQL.

For more information, see the Apache Cassandra web site.

Requirements

  1. Java >= 1.8 (OpenJDK and Oracle JVMS have been tested)

  2. Python 3.6+ (for cqlsh; 2.7 works but is deprecated)

Getting started

This short guide will walk you through getting a basic one node cluster up and running, and demonstrate some simple reads and writes. For a more-complete guide, please see the Apache Cassandra website’s Getting Started Guide.

First, we’ll unpack our archive:

$ tar -zxvf apache-cassandra-$VERSION.tar.gz
$ cd apache-cassandra-$VERSION

After that we start the server. Running the startup script with the -f argument will cause Cassandra to remain in the foreground and log to standard out; it can be stopped with ctrl-C.

$ bin/cassandra -f

Now let’s try to read and write some data using the Cassandra Query Language:

$ bin/cqlsh

The command line client is interactive so if everything worked you should be sitting in front of a prompt:

Connected to Test Cluster at localhost:9160.
[cqlsh 2.2.0 | Cassandra 1.2.0 | CQL spec 3.0.0 | Thrift protocol 19.35.0]
Use HELP for help.
cqlsh>

As the banner says, you can use 'help;' or '?' to see what CQL has to offer, and 'quit;' or 'exit;' when you’ve had enough fun. But lets try something slightly more interesting:

cqlsh> CREATE KEYSPACE schema1
       WITH replication = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
cqlsh> USE schema1;
cqlsh:Schema1> CREATE TABLE users (
                 user_id varchar PRIMARY KEY,
                 first varchar,
                 last varchar,
                 age int
               );
cqlsh:Schema1> INSERT INTO users (user_id, first, last, age)
               VALUES ('jsmith', 'John', 'Smith', 42);
cqlsh:Schema1> SELECT * FROM users;
 user_id | age | first | last
---------+-----+-------+-------
  jsmith |  42 |  john | smith
cqlsh:Schema1>

If your session looks similar to what’s above, congrats, your single node cluster is operational!

For more on what commands are supported by CQL, see the CQL reference. A reasonable way to think of it is as, "SQL minus joins and subqueries, plus collections."

Wondering where to go from here?

About

Mirror of Apache Cassandra

Resources

License

Stars

Watchers

Forks

Packages

No packages published

Languages

  • Java 96.4%
  • Python 1.9%
  • HTML 1.0%
  • Shell 0.4%
  • GAP 0.3%
  • Lex 0.0%