Keynote RedAlert is a hosted web and network device monitoring service offered by Plano Texas's Keynote Systems, Inc. They offer a 30-day free trial, which I took, and which is supposed to be a fully-functional version of their monitoring system. I added the 5 URLs I generally use for these trials, hosted at various locations in California. These reference sites tend to have a good amount of variability, and at least one of them is flaky enough that I thought it might give us a workout.
First, the system itself. They have multiple locations from which RedAlert will crawl your site. The interface itself took some getting used to, as it is somewhat less than verbose, and not terribly well-designed. That aside, however, I had no trouble adding my 5 sample URLs. Be warned, though, what the first page lacks in options, the next page more than makes up for. When you add a URL, it takes you to a page only slightly shorter than the Gutenberg Bible and chock full of fiddly options.
You enter the URL, give it a shorthand name, and choose either a 5 minute or 15 minute crawl interval. So far so good. Then it asks you for an optional keyword, and suggests that you scroll down the page to learn more about Error Type 4. You can give it a username and password, optional fields to post to a form, options about following redirections and whether or not to check a router or switch in association with this device (for which you need to provide an IP address).
Next there are near-identical tables in which you configure your response to each of 7 different error types, ranging from 'Device inaccessible' to 'File Size Error'. I only used the first three, namely 'Device Inaccessible', 'Device Not Accepting TCP Connections', 'No Data Sent Within 30 Seconds of Request', and in each case, asked them to send me an email alert up to twice, and when the device recovered. You can also choose how long the error needs to persist before someone is notified (I chose immediate notification), the email address to notify, and a range of times to crawl (apparently, in case your website is only being used from 9 to 5).
I did have to examine all of these options for each of the devices I added, however, much later, when clicking around, I came across a link to 'bulk edit notification options', under Alerts => Edit Notifications. They do appear to have a lot of features, it is just that the user interface is so horrible that I eventually stopped looking for them.
Each day, RedAlert sent me an email message 'Monitoring Statistics from RedAlert', which almost invariably told me that my URLs had 100% uptime. Unfortunately, they didn't convey any other data, such as the average response time, heavy load periods, or anything like that. Still it was vaguely reassuring, and I could have asked it to stop sending me those messages.
Other monitoring systems, running concurrently, seemed to think these URLs had a bit more downtime than RedAlert reported. However, whenever RedAlert did send me a failure notification (which it did three times that month), the other systems concurred. This gave me even more confidence when I send the webmaster an email asking them to look into it. Anyone who co-locates machines with smaller firms knows that it is sometimes difficult to get them to admit when there is very occasional, but very real flakiness on their network.
RedAlert has a number of features that I did not test, but I presume work fine. They can monitor many other types of internet service, such as FTP server, SMTP, POP3, IMAP, etc. Notifications can be sent via pager, SMS, etc. Be warned, though, that they charge you for every conceivable option, and it ain't cheap.
All in all, this is a system with an extensive (albeit expensive) range of options, but a difficult user interface that might keep people from getting the most out of their service.
