Monthly Archives: July 2015

How to Limit Resources Using cgroups on CentOS 6

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 »

How to Back Up a LAMP Server with Bacula on Ubuntu 14.04

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 »

How to Detect Anomalies with Skyline on CentOS 7

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 »

How To Install And Configure Mod_deflate On Ubuntu 14.04

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 »

How to Upgrade OSSEC 2.8.1 to OSSEC 2.8.2

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 »

How To Set Up mod_rewrite for Apache on Ubuntu 14.04

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 »

How To Set Up a Node.js Application for Production on CentOS 7

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 »

How To Use Prometheus to Monitor Your Ubuntu 14.04 Server

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 »