Apache Cassandra™ is a massively scalable open source NoSQL database. Cassandra is built from day 1 to be clustered to tick the usual clustering boxes; no single point of failure, and capacity and throughput scales with cluster size. This guide will look at creating a three node basic cluster within a single data centre. It is assumed
Cassandra uses various ports for communication, either server to server communication or client to server communication. If you’re using Cassandra in a firewalled environment you may need to open various ports depending on your needs. All ports are TCP and can be configured in the relevant config files to use non-default ports.
The following process will install the DataStax distribution of Cassandra on any Debian based system, such as Debian or Ubuntu. We’ll use the official DataStax apt repositories to install Cassandra using apt-get. Cassandra is written in Java and the latest version (at the time of writing) of Cassandra requires Java 8. You can use either OpenJDK or
The below script installs the DataStax distribution of Cassandra 3.2.x and the latest Oracle Java 8 on Debian. Copy and paste the script into a file called install_cassandra.sh and execute it as root. [crayon-57710056be337224829235/] Then connect to the local Cassandra instance run the cqlsh tool. [crayon-57710056be341380981175/]
I keep finding new uses for GitHub Pages - situations where in the past I would otherwise have spun up a web site on heroku or similar. But if the site can be static, and especially if you are already hosting the git repository at GitHub, Pages are perfect.
For a long time, I've maintained the LittleArduinoProjects project index as a simple table in the README. But it wasn't particularly nice or usable, so I (more...)
MongoDB is one of the leading noSQL breeds of database that’s been growing in popularity in recent years. The database is available in a ‘community edition’ that’s available for all to use freely. The database setup and install is mostly straightforward however there are a few steps you have to take to get a MongoDB
The below script installs MongoDB 3.2.x on Debian. Copy and paste the script into a file called install_mongo.sh and execute it as root. [crayon-57643d1def52c510890489/] Then connect to the local MongoDB instance [crayon-57643d1def535550281613/]
Let me start by saying… this is a quick and dirty method and shouldn’t be used for precise comparisons of CPU performance. That said, it’s perfectly adequate for approximating CPU performance, especially on Cloud hosted VPSs to ensure you’re getting the horsepower that you’re being promised. The idea here is to force your machine to
I'm working on an idea where I need to measure temperatures to around 500°C - above those typically supported with semiconductor sensors or thermistors.
This project demonstrates the basic approach using an Arduino as the "temperature logger". I'm using a K Type thermocouple that's rated up to 700°C. Since thermocouples only measure a differential temperature, I'm also using an LM35 to provide the cold-junction baseline. The temperature measurement is displayed on a 5110 LCD.
Oracle Java, due to Oracle’s license conditions, it quite a pain to install. The problem is that anyone who isn’t Oracle isn’t allowed to distribute the JDK binaries – they have to be downloaded strictly from Oracle. Luckily the guys over at webupd8team have been creative in this area and created and apt-get package that downloads the
In this blog post we’re going to take a detailed look at the Ceph server processes within a Ceph cluster of multiple server nodes. Ceph is a highly available network storage layer that uses multiple disks, over multiple nodes, to provide a single storage platform for use over a network. Ceph is designed to be fault tolerant
SpamAssassin does a great job at identifying SPAM emails and is probably one of the most popular in it’s class. An important part of fighting SPAM email is keeping up with the changes in both SPAM and non-SPAM (often called Ham) email content. Luckily for us, whatever magic SpamAssassin employs to decide if email is SPAM
One of the best finds in the racks at Tower Records Fukuoka福岡市. It's been years since I last got to browse a record store in Japan; I'm glad they still exist, with stacks of CD players queued up to sample. And a huge relief to see the indie rock scene is just as vibrant as I remember!