Watching The Defectives

PC Pro logo Posted: 1st May 1998 | Filed under: Press Articles, Technical
Author: Paul Ockenden
First Appeared in PC Pro 1998

If you look after or host Web sites for clients, there's one certainty: if the site is ever unavailable, the client will be trying to view it at exactly that time. Sites can go down for various reasons: a server hardware fault, software crash, power failure, problem with a leased line or a peering problem with your ISP. Each will have the same effect: visitors won't be able to access your Web site.

There a number of server watcher programs available, but be careful where you run the monitoring software. You can't run it on the same machine as the Web server, because if that machine goes down so does your monitoring. If you run it on another local server it may still fail to work if you have a catastrophic power failure. Also, you'll only be able to monitor the on-site network. You may get reports saying that the site is responding well, while that JCB you can see through the office window has just severed your leased line.

For monitoring to work well it, therefore, has to run off-site, preferably from a site which uses a different ISP to you, so that you're notified of any downtime due to routing problems. Spot the obvious problem? If the monitoring software is running at another site, how does it notify you that your site's down? A beep isn't going to work and email would be pointless, as if there's been a Web failure then your incoming email is probably failing, too.