In last post of this series we learnt about how to add nodes in a cassandra cluster. If you have missed earlier posts of this series

then you can read them from below links:

1: Introduction to Cassandra

2: Understanding Cassandra Read/Write Mechanism

3: Installing Cassandra on RHEL6

4: Adding Node To Cassandra Cluster

In this post we will explore nodetool and will see how we can manage a cassandra cluster using nodetool utility.

What is nodetool?

The nodetool utility is a command line interface for managing a cluster. It provides a simple command line interface to expose operations and attributes available with cassandra.

There are hundreds of options available with nodetool utility and in this post I will cover only those which ae used more often.

Note: This post is suitable for those admins who are not sevrice owners of cassandra nodes/cluster but have to interact with cassandra day in day out in their infrastructure.… Read More

In last post of this series we learnt how to install cassandra on Rhel 6. In this post we will look into additional configuration parameter that is needed to configure in order to facilitate other nodes to join the cassandra cluster.

If you have missed earlier posts of this series then you can read them from below links:

1: Introduction to Cassandra

2: Understanding Cassandra Read/Write Mechanism

3: Installing Cassandra on RHEL6

At the moment we have one node cassandra cluster. Before going ahead and installing cassandra on other nodes, we will first perform following configuration changes in cassandra.yaml file.

Navigate to cassandra.yaml file which is located in cassandra_install_dir/conf folder. Open the file in editor of your choice and look for following options:

• Listen_address: Address where gossip will be listening to. This address can’t be localhost or 0.0.0.0, because the rest of nodes will try to connect to this address.

… Read More

In last 2 posts of this series we learnt about Cassandra architecture and understood the cassandra Read/Write process.

If you have missed earlier posts of this series then you can read them from below links:

1:Introduction to cassandra

2: Understanding Cassandra Read/Write Mechanism

In this post we will learn about installing cassandra on Redhat Linux.

Before jumping into lab and start with installation, I want to touch down on few concepts first which will help in understanding installation process.

Bootstrapping

Bootstrapping is the process in which a newly-joining node gets the required data from the neighbors in the ring, so it can join the ring with the required data. Typically, a bootstrapping node joins the ring without any state or token and understands the ring structure after starting the gossip with the seed nodes; the second step is to choose a token to bootstrap.

During the bootstrap, the bootstrapping node will receive writes for the range that it will be responsible for after the bootstrap is completed.… Read More

In first post of this series we discussed about what is cassandra, what are the benefits of using cassandra. We also discussed a little bit about from where cassandra came and finally we looked at the architecture of cassandra and discussed some important terms like snitch, gossip, data replication, partitioner etc.

In this post we will see how cassandra Read/Write mechanism works.

Let’s discuss about some key components of cassandra first before discussing about Read/Write. Important components of cassandra can be summarized as below:

1: Node – This is the most basic component of cassandra and it is the place where data is stored.

2: Data Center – In simplest term a datacenter is nothing but a collection of nodes. A datacenter can be a physical datacenter or virtual datacenter.

3: Cluster – Collection of many data centers is termed as cluster.

4: Commit Log – Every write operation is written to Commit Log.… Read More

Cassandra was very new to me when I joined the vCloud Air operations team back in 2015. Over last 1.5 years I have got a bit of understanding about cassandra now and it provoked me to learn this wonderful database technology.

To start my journey with Cassandra, I am following training course from Infinite-Skills and youtube videos along with documentation available from datastax.

As my journey will progress, I will keep writing and sharing my experience of learning about cassandra.

This is very first post of learning cassandra series where I will try to touch down few basic things about cassandra.

What is cassandra?

cassandra is a NoSQL database technology. NoSQL is referred as not only SQL and it means an alternative to traditional relational database technologies like MySQL, Oracle, MSSQL. Apache cassandra is a distributed database. With cassandra database do not lives only on one server but is spread across multiple servers.… Read More