Java is a popular language for business and enterprise computing. Java and the JVM have enjoyed enormous success over the last two decades. The JVM was initially considered a slow language (late 90’s). That changed with the introduction of the HotSpot virtual machine in April 99. HotSpot improved performance via “just in time” compilation and adaptive optimisation. […]
CAP Theorem
The CAP theorem is a tool used to makes system designers aware of trade-offs while designing networked shared-data systems. CAP has influenced the design of many distributed data systems. It made designers aware of a wide range of tradeoff to consider while designing distributed data systems. Over the year the CAP theorem has been widely […]
Reasons for unbalanced Cassandra Cluster
Sometimes an Apache Cassandra cluster can end up in an unbalanced state. An unbalanced state is where data is unevenly distributed across a cluster or locally configured data directories. There are a number of reasons this can happen. In this blog post, I will cover two basics reasons this might happen. A cluster can end up […]
Understanding an Apache Cassandra Memtable Flush
A recent question in the Apache Cassandra mailing list triggered this blog post. The question revolved around events that trigger a memtable flush. Understanding the root cause of a memtable flush is essential to get a better understanding of Apache Cassandra. Another question that frequently crops up is the size of an SSTable as a result of […]
Cassandra Query Language (CQL) Tutorial
Apache Cassandra and the Cassandra Query Language (CQL) have evolved over the past couple of years. Key improvements include: Significant storage engine improvements Introduction of SSTable Attached Secondary Index i.e SASI Indexes Materialized views Simple role based authentication This post is an updated to “A Practical Introduction to Cassandra Query Language”. The tutorial will concentrate […]
Configuring Apache Cassandra Cluster with Docker
This tutorial outlines steps to install and configure Apache Cassandra using Docker. Docker provides an easy way to create an Apache Cassandra cluster. Using Docker we will get an Apache Cassandra cluster up and running in minutes
Apache Cassandra Data Modelling Principles
Designing an effective data model is imperative to scale any application. This is true both in the relational and non relational world. Data modelling in Apache Cassandra is no different than any relational database. It requires a good understanding of the target domain and usage patterns within the domain. A deep understanding of your target […]
Debugging Transactional And Locking Issues in MySQL
Introduction Database transactions are a logical unit of work or a group of related changes executed against a database. Transactions enable us to execute reliable units of work against a database and recover in case of failures. Transactions are “all-or-nothing” i.e they enable us to either execute all changes within the logical group or have […]
A Practical Introduction To Cassandra Query Language
Cassandra Query Language (CQL) Tutorial is an updated version of this tutorial. It is applicable to Apache Cassandra version 3.x and above. Continue to use this tutorial if you are using Apache Cassandra version 2.x.x. Introduction In two earlier posts, An Introduction To Apache Cassandra and Apache Cassandra Architecture, I provided a theoretical overview of […]
Apache Cassandra Architecture
Introduction An Introduction To Apache Cassandra , introduced us to various types of NoSQL database and Apache Cassandra. In this article I am going to delve into Cassandra’s Architecture. Cassandra is a peer-to-peer distributed database that runs on a cluster of homogeneous nodes. Cassandra has been architected from the ground up to handle large volumes of data while providing […]