Web site monitoring may be performed by your Web site hosting service, they may supply software for your use, or you may have to install your own. read about the alternatives and some free software.
A hosting service
Some Web site hosting companies offer Web site and Web server monitoring as part of the service or as an optional extra for a few dollars per month. The service provides a basic check. Your Web site could be severely crippled and still respond with a Web page that will satisfy most Web site monitors.
You usually need a deeper check to make sure your Web site can respond in a useful way. Pick a complex Web page that returns information from your database, something that is updated frequently and is time dependent. You can then add something to read the page every few minutes and make sure the data is up to date. Your Web hosting company might insert your test script into their monitoring system. Expect them to request a script written in Perl or some other ancient language.
Web site hosting companies are more likely to monitor your Web and database servers when you have several of each and a way to switch between them. They can then create a script to perform the switch automatically and notify you when the switch is finished.
Free open monitoring tools
Big Brother used to be a contender in this area but went all commercial.
Munin is written in Perl. If you are so old that you can remember Louis de Pointe du Lac saying
So you want me to tell you the story of my life? at the premiere of the movie Interview with the Vampire, you probably remember writing Perl scripts to create web pages. Perl programmers should compare Munin to NeDi, the other Perl based monitor. If either application is close to your requirement and missed by just a small amount, you could contribute to the development of those applications until they meet your exact requirement.
Despite the availability of Perl on Windows, there is no Windows version of Munin. Download Munin from munin-monitoring.org.
Nagios is free, open source, and popular. Download Nagios from www.nagios.org. You will need a Linux server to run Nagios and a C compiler to compile Nagios of source code. You can add a Web server, such as Apache, for Web access. A Web server provides the most convenient way to update your monitoring settings.
Good things about Nagios:
- The popularity makes Nagios a good long term bet and ensures a wide range of add on modules.
- Nagios has a lot of add on modules for monitoring obscure hardware.
Bad things about Nagios:
- If you do not find an add on module to monitor exactly what you want then you are stuck with detailed programming, which is a real roadblock for most people.
- There are no downloads for precompiled binaries.
- There is no windows version which means you cannot monitor a Windows based system from within the system.
There are enough bad things about Nagios to look at OpenNMS first.
NeDi uses Perl to monitor stuff and PHP for a Web based interface. NeDi might be easier for some older Web developers who had to learn Perl but not for everyone else. Most people will choose whatever works without programming of any kind. NeDi appears to be too early in development to have lots of add ons for everything you want to monitor. Development and documentation appears to depend on one person.
OpenNMS is completely open source and not crippled by a commercial version, the way Zenoss is. OpenNMS has binary downloads, placing OpenNMS ahead of Nagios. OpenNMS can run in a Windows machine, placing OpenNMS ahead of practically everything else. Given that so many web sites are developed and tested on local windows based computers, running a test OpenNMS from one of those machines makes life easier for some smaller Web development teams.
The one disadvantage of OpenNMS is the use of Java. Java is starting to get to the stage where it is usable on every operating system. Thanks to a major improvement developed by Microsoft, Java is starting to catch up to the performance of normal programming languages. If you need to run a monitoring system from a Windows box, consider OpenNMS. For non Windows environments, look at all the other applications.
Pandora FMS has documentation in English, Japanese, and Spanish. The development is in Spain and some of the Web site pages are only in Spanish. The download analysis published on their Web site shows Spain and Cuba among the top download countries. Download Pandora FMS from pandorafms.org.
The Pandora FMS server runs on Linux but not on Windows. The database is MySQL. The Web interface is written in PHP. There is a lot to like about Pandora FMS and nothing stands out ahead of all the other choices except the Spanish language, which should make Pandora FMS popular in South America.
Download Zabbix from zabbix.com.
Zabbix has the advantage of working with most of the popular databases, MySQL, Oracle, PostgreSQL, and SQLite. Zabbix is completely free from Java, giving you efficiency and reliability in the server component. The Zabbix Web interface is PHP based, giving Web developers the chance to develop their own requirements, and to contribute improvements.
I like the documentation and the documentation is available in English, French, Japanese, Portuguese, and Russian. When they bring out a Spanish translation, Zabbix might wipe out Pandora FMS.
Zenoss is split into an open source community edition and a commercial version. I hate the wording of the Zenoss site because it is a sales pitch for paranoid IT managers with big budgets. Zenoss warn potential users that the open source version might lead to legal action of IP infringement and offer the commercial version with legal protection but the legal protection is only for Zenoss, not the customer, and the commercial version includes the open source version, which suggests the open source version must be safe.
Most people will need only the free open version but look at the commercial version as part of your planning. One day you could need one of those commercial add on products and have to buy the fee. Think about investing a lot of time in the building of a large monitoring system then being forced on to the commercial version. Perhaps you should start with a completely open product. OpenNMS looks comparable and is open.
If you use Windows exclusively, look at OpenNMS. Oracle users look at Zabbix. Spanish readers will like Pandora FMS. People who want to spend big will look at Zenoss. Your Unix system administrator may already know how to use Nagios. There is no clear leader for any other reason.