Introduction We’re finally ready to set up centralized logging for our production application setup. Centralized logging is a great way to gather and visualize the logs of your servers. Generally, setting up an elaborate logging system is not as important as having solid backups and monitoring set up, but it can be very useful when… Read More »
Introduction CoreOS is a Linux distribution focused on quickly spinning up clustered environments by utilizing Docker containers and service discovery. If you’re new to CoreOS. However, Docker images can occupy quite a lot of disk space on the Docker host. A base image can be hundreds of MB in size and custom images can easily… Read More »
Introduction Control groups, or cgroups, is a kernel feature introduced in CentOS 6 to provide a new way of limiting access to system resources for processes. You can create your own cgroups, monitor the cgroups you configure, deny cgroups access to certain resources, and even reconfigure your cgroups dynamically on a running system. In this… Read More »
Introduction After getting your application server up and running, an important next step is to set up a backup system. A backup system will allow you to create periodic backup copies of your data, and restore data from those backups. As data can be lost due to user error or the eventual hardware failure that… Read More »
Introduction If you use a monitoring system (like Zabbix or Nagios) then you know how monitoring works. In a nutshell it can be described as follows: A monitoring system receives various metrics (CPU/memory usage, network utilization, and more). As soon as the value of one of the metrics goes outside the predetermined thresholds, it activates… Read More »
Introduction Mod_deflate is an Apache module which allows output from your web server to be compressed before being sent to the client. Once the size of your site content is compressed, its size is smaller, and clients are able to download it faster. This is valuable not only for clients with lower bandwidth, but it… Read More »
Introduction OSSEC is an open-source, host-based intrusion detection system (HIDS) that performs log analysis, integrity checking, Windows registry monitoring, rootkit detection, time-based alerting, and active response. It can be installed to monitor a single server or thousands of servers. This tutorial shows how to upgrade an installation of OSSEC 2.8.1 to the latest release, OSSEC… Read More »
Introduction In this tutorial, we will activate and learn how to manage URL rewrites using Apache2’s mod_rewritemodule. This tool allows us to rewrite URLs in a cleaner fashion, translating human-readable paths into code-friendly query strings. This guide is split into two halves: the first sets up a sample web application and the second explains commonly-used… Read More »
Introduction Node.js is an open source Javascript runtime environment for easily building server-side and networking applications. The platform runs on Linux, OS X, FreeBSD, and Windows, and its applications are written in JavaScript. Node.js applications can be run at the command line but we will teach you how to run them as a service, so… Read More »
Introduction Prometheus is an open source monitoring system developed by SoundCloud. Like other monitoring systems, such as InfluxDB and Graphite, Prometheus stores all its data in a time series database. However, it offers a multi-dimensional data-model and a powerful query language, allowing system administrators to not only easily fine tune the definitions of their metrics,… Read More »