apache cassandra tutorial - Wikitechy

What is the use of Cassandra database ?

Editor — Tue, 13 Jul 2021 05:36:30 +0000

Apache Cassandra is a high-performance provides database to manage large number of data among many commodity servers and then it is highly scalable.
It is a type of NoSQL database.
Apache Cassandra can be used for different applications.

In activity-tracking and monitoring applications:

Numerous entertainment and media organisations use Cassandra to observe user activity based on movies, music, albums, artists or other parameters.

In heavy write systems or in time-series-based applications:

Cassandra is best for heavy write systems .For example, data is logged for each request based on hits in web analytics, by type of browser, traffic sources, position, character, technology, tools, etc.

In social media analytics:

Cassandra is used by many social media providers to recognize the data and gives recommendations to their users.

In product catalogues and retail applications:

A very popular use case of Cassandra is to show fast product catalog inputs and lookup, and in retail applications.

Messaging:

Cassandra serves as the database backbone for countless mobile phone and message providers applications.

Apache Cassandra is a high-performance provides database to manage large number of data among many commodity servers and then it is highly scalable.

Editor — Tue, 13 Jul 2021 05:30:15 +0000

Once you’ve absorbed that the strategy should fit the kind of environment you are placing your cluster in.
If you want to stay in one region of Amazon web services? You can either set yourself up as one dc per availability zone (AZ), or you can set up your cluster to use one dc and treat the AZs as racks.
Then you can replicate so that if an AZ goes down you won’t have a system problem, just some downed and unavailable servers.
If an AZ goes down (or a rack goes down) that all the copies of an important piece of data will be available.
You also are stuck with latency issues if you want to cross into a different region.
Your data has to replicate into the new region and if you went ‘simplestrategy’ you are going to have massive traffic trying to keep the database in sync.

Editor — Tue, 13 Jul 2021 04:54:18 +0000

Cassandra database is distrubuted over multiple machines that perform together.
The outermost container is known as the Cluster. For failure handling, every node have a replica, and in case of a failure, the replica takes charge.
Cassandra order the nodes in a cluster, in a ring format, and assigns data to them.
The data model of Cassandra is significantly various from normally what can we see in an Relational Database Management System.

The Group of independent servers (usually in close proximity to one another) interconnected via network to work as one centralized data processing resource.
Clusters are working for multiple complex instructions by distributing workload across all connected servers.
Clustering develops the system’s accessibility to users, its aggregate performance, and overall tolerance to faults and component failures.
A failed server is automatically shut down and its users are switched immediately to the other servers.

The basic attributes of a Key space in Cassandra are,

It represent the cluster contain the number of machines that will collect duplicate of the same data.

It is nothing but the strategy to point replicas in the ring.
We have strategies such as simple strategy (rack-aware strategy), old network topology strategy (rack-aware strategy), and network topology strategy (datacentre-shared strategy).

Key space is a edge for a order of one or more column groups.
A column groups, in turn, is a edge of a order of rows. Each row have a ordered columns.
Column families define the structure of your data.
Each keyspace contain at least one and often many column families.

Editor — Tue, 13 Jul 2021 04:45:53 +0000

Amazon’s dynamo and Prashant malik are written by Avinash Lakshman at first succeed Cassandra at Facebook to capable the Facebook inbox search purpose.
In July 2008,Facebook published Cassandra as an open-source project on Google code.
In March 2009 it develop an Apache incubator project.
On february 17, 2010 it qualify to a top-ranking project.

Releases after graduation include

Added help for integrated caching, and Apache Hadoop MapReduce distributed 0.6 in Apr 12 2010.
Added secondary indexes and online schema changes distributed 0.7 in Jan 08 2011.
Added the Cassandra Query Language (CQL), self-tuning memTables, and help for zero-downtime upgrades distributed 0.8 in Jun 2 2011.
Added integrated compression, levelled compaction, and improved read-performance distributed 1.0 in Oct 17 2011,
Added self-tuning caches, row-level isolation, and support for mixed ssd/spinning disk deployments distributed 1.1 in Apr 23 2012,
Added clustering among virtual nodes, inter-node communication, atomic batches, and request tracing distributed 1.2 in Jan 2 2013,
Added lightweight transactions (based on the Paxos consensus protocol), triggers, improved compactions distributed 2.0 in Sep 4 2013,
In Sep 10 2014 publish 2.1
In July 20, 2015 publish 2.2
In November 11, 2015 publish 3.0
Monthly publish tick-tock like release model in 3.1 across 3.10. When even-numbered contain both bug fixes and new features while odd-numbered involve bug fixes only.
In June 23, 2017 publish 3.11 as a stable and it distributed series and bug fix from the last tick-tock characteristic publish.