Название: Apache Cassandra Horizontal scalability for Java applications (2022 Update)
Автор: Otavio Santana
Издательство: Leanpub
Год: 2022-09-17
Язык: английский
Формат: pdf (true), epub
Размер: 11.1 MB

In the competitive world of technology, millisecond improvements in performance can make all the difference for your customers. From this need, several paradigms and frameworks emerged, demanding, at the same time, a good and fast performance in the persistence of information. Apache Cassandra was born in this scenario, the NoSQL database, elastic, fault-tolerant, and with a high degree of performance. Cassandra is a non-relational database originated by Facebook. Today, it is an open-source project within the Apache Foundation with successes in the world's largest companies, such as Netflix, GitHub, eBay, among others.

In this book, Otávio Santana discusses Cassandra, its concepts, and its applicability with Java. After introducing non-relational databases, you will see concepts such as hierarchy, reading, writing, how they work on the node, and their orchestration within a Cluster. The practical operation of the communication language Cassandra Query Language or CQL will be presented, with modeling tips and mapping frameworks. DataStax Mapper, Spring Data Cassandra, Hibernate OGM Cassandra, and Eclipse JNoSQL.

NoSQL databases are a class of persistence technology that provides a new storage mechanism that innovates compared to the widely used normalization and relational databases. It has the same objectives as every other database, that is, to insert, update, retrieve, and delete information, however, with new concepts of modeling and storage structure.

The term NoSQL was initially related to “not SQL” and was later extended to Not Only SQL, that is, “not just SQL”, coining the concept of polyglot awareness (the work of dealing with different types of databases to reach the objectives in the application). The main characteristics of these databases are speed and a high rate of scalability, as well as the facility to increase the number of database servers. This prevents operations’ bottlenecks, avoids having a single point of failure, and distributes the servers geographically bringing the data closer to the users who are making the requests. NoSQL databases are being adopted more frequently in several types of applications, including applications for financial institutions. As a consequence, the number of suppliers for this type of database is also growing.

Currently, NoSQL databases are classified into four groups (key value, column family, document, and graphs) defined by their storage model:
When understanding a new concept, it is useful to make a comparison with existing knowledge. Thus, considering that relational databases are very famous, we will make a comparison between relational databases and NoSQL throughout this chapter.

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