KVM & BRCTL in Linux – bringing VLANs to the guests

I recently had the opportunity to setup a KVM machine running on a Centos machine. Tools such as Virtual Machine Manager (VMM) help immensely in the provisioning and administration of virtual machine guests within KVM, and bring the KVM solution on par with other solutions such as Xen, VMWare and VirtualBox. Networking is one of … Continue reading KVM & BRCTL in Linux – bringing VLANs to the guests

Troubleshooting Centreon graphs

Symptom: Centreon stopped graphing performance data completely. There are quite a large number of reasons why this would happen, in fact a quick google search will come up with some very good articles, the few which I found useful were: http://en.doc.centreon.com/Setup:Graphs#Perfdata_activation_in_Nagios http://en.doc.centreon.com/Troubleshooting:Graphs http://felipeferreira.net/?p=1019 However, alas none of the points mentioned in the above articles worked … Continue reading Troubleshooting Centreon graphs

Sending nagios / centreon notifications via IRC

Lately we needed to find a convenient method of notifying service desk operators of centreon notifications. Email was not a good option since operatives tended to simply delete the messages. Besides, we wantede something a bit more realtime. In the end, I decided on using IRC. I went with IRC rather than jabber due to … Continue reading Sending nagios / centreon notifications via IRC

Monitoring Tomcat via JMX–Lessons Learned: Part 2

In my previous post I mentioned that the check_jmx plugin I've used for monitoring JMX does not output perfdata data, which is useful for programs such as Centreon and Nagios which use this data to graph the output of the plugin. The developers have made an excellent job with this plugin, and I hope they … Continue reading Monitoring Tomcat via JMX–Lessons Learned: Part 2

Monitoring Tomcat via JMX–Lessons Learned: Part 1

Requirement : monitoring vital Tomcat statistics such as active & idle threads, memory consumption and so on. JMX (java monitoring extensions) is quite well documented – so a google search should bring you up to speed, but in a nutshell, JMX is almost like a java-centric SNMP. Java app developers can make certain attributes such … Continue reading Monitoring Tomcat via JMX–Lessons Learned: Part 1

Linux script for automatic notification of failed download

Scenario: We need a CentOS machine to periodically automatically download a file from a remote server on the internet. If this download fails for any reason, the network admin should be emailed to investigate further. Resolution: A simple cron job can be used which executes a download script. The following script was used: #!/bin/bash wget … Continue reading Linux script for automatic notification of failed download

Easy cisco syslog monitoring using Webmin

At some point probably a network team would need something similar to this, so I thought it would be a good article to document what I’ve used to achieve this scenario: There is a need to monitor multiple CISCO boxes, and these logs should be easily accessible internally to a team of network admins, some … Continue reading Easy cisco syslog monitoring using Webmin