May 102014
 

terminal1.jpg
Your server appearing pretty slow could be many things from wrong configs, scripts and dodgy hardware – but sometimes it could be because someone is flooding your server with traffic known as DoS ( Denial of Service ) or DDoS ( Distributed Denial of Service ).

Denial-of-service attack (DoS attack) or Distributed Denial-of-service attack (DDoS attack) is an attempt to make a machine or network resource unavailable to its intended users. This attack generally target sites or services hosted on high-profile web servers such as banks, credit card payment gateways, and even root nameservers. DoS attacks are implemented by either forcing the targeted computer to reset, or consuming its resources so that it can no longer provide its services or obstructs the communication media between the users and the victim so that they can no longer communicate adequately.

In this small article you’ll see how to check if your server is under attack from the Linux Terminal with the netstat command

Continue reading »

flattr this!

Aug 212012
 

This is an article of mine, first published on Wazi

Every organization must monitor its infrastructure’s uptime and performance. While the popular Nagios application is a good general-purpose monitoring program that you can extend with plugins to handle just about any task, you may do even better by employing Cacti as a graphical front end to RRDTool‘s data logging and graphing functionality. Cacti was developed specifically to monitor and collect performance information, while Nagios is more oriented toward state changes, such as noting whether a daemon is up or down.

RRDTool stores all of the necessary information to create graphs and populate them with data in a MySQL database. Cacti provides templates to gather and show information such as system load (CPU, RAM, disks), users connected, MySQL load, and Apache load, all of which can affect the performance of your site.

Cacti’s front end is completely PHP-driven. It supports data gathering via different methods such as scripts in any language and SNMP.

Continue reading »

flattr this!