Christopher J. Buckley » Monitoring

Monitor your server OS and Applications – Munin

Chris — Mon, 28 May 2007 14:39:06 +0000

Recently, i’ve become aware of a fantastic monitoring tool that allows easy visilibity of server clusters. The program is called Munin. The authors address their program as:

[Munin] The monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on plug and play capabilities. After completing a installation a high number of monitoring plugins will be playing with no more effort.

Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine “what’s different today” when a performance problem crops up. It makes it easy to see how you’re doing capacity-wise on any resources.

So, i’ve implemented Munin across my platform of servers – as I write this I have implemented monitoring of my load-balancer and web/mailserver box. ~~There is a secondary web-server to be bought online soon.~~

Of special interest to me in this program is the ability to track the replication of MySQL, I can now easily see (and be alerted to via Nagios) any lag in my replication ’seconds behind master’ time.

Please take a look at the monitoring information at: monitors.cjbuckley.net

OSSEC rulesets for Zeus Webserver and ZXTM

Chris — Fri, 04 May 2007 13:27:04 +0000

OSSEC is a leading Intrusion Detection System for Enterprise UNIX(-like) and Windows platforms. OSSEC is, by quite a way, the most innovative and customisable IDS product I have worked with.

As a result of it’s ease of customisations, the developer Daniel B. Cid, with a little bit of help from myself, have implemented supported rule-sets for my former employers’ products: Zeus WebServer and ZXTM. Both products are widely deployed across many enterprise environments; adding specific rulesets for their software is one which I hope assists all fellow sysadmins tasked with running infrastructure using Zeus software.

Download

You can download the latest snapshot of OSSEC from this page.

Implementation

After running install.sh you can add the Zeus rulesets as you would any other supported rule set.

Example:

syslog
/usr/local/zeus/zxtm/zxtm/log/errors

syslog
/usr/local/zeus/zws/web/log

Alerts

Below you can clearly see the ruleset alerting you, quickly and efficiently, to a failure.

Help..

Any questions, just ask!

How to professionally monitor your website uptime

Chris — Tue, 10 Apr 2007 11:57:03 +0000

A common problem faced by a webmaster is, how do I accurately monitor my website’s availability?
This website, for example, has both internal and external health monitors dedicated to achieving high-availability.

Internal

This site’s traffic manager performs a HEAD request for /blog/ every 5 seconds, and makes sure a valid HTTP status code is recorded. This is done through a simple regex of ^[234][0-9][0-9]$.

Further, health monitors ‘ping’ and ‘TCP connect’ are enabled to make sure a) the box is up b) the desired socket is able to receive connections.

External

So, we’ve got good internal monitors in place. But how do we check on the availability/performance of our site over a WAN? Two sites I have knowledge of and can recommend are:

Site Confidence monitor website performance for many of the UK’s largest companies, including many well-known brands and businesses such as; Norwich Union, Auto Trader, Marks & Spencer, John Lewis, First Choice and Experian.
HostTracker is a free-to-use service, with 52 different testing nodes in Europe, The Americas and Asia.

The beauty of the services above is that they allow you to input POST form data; this allows a webmaster to perform a transaction against his service – remotely. If you stop transacting, it’s best you know first, rather than your customers ringing up to complain.