You can be alerted for a variety of reasons. Remember that behind
the scenes of a page request and transfer lies multiple networks,
routers, DNS tables, servers, etc. If any one of these fails, even
for a moment, and KnightGuard.Net happens to be monitoring it at the
time, you may get an alert that your site is down.
This is the same scenario as if you are browsing with Netscape or
Internet Explorer, and you need to reload a page because it did not
load properly the first time. The first time you try, it failed! If
that was KnightGuard.Net requesting the page that did not transfer,
it would send an alert - even if the next time would succeed*.
There are many reasons you may be alerted. Here are a few:
A "Hickup"
Hickups are probably the most comon reason a site goes down or is
unavailable. If a network router or server needs to be reset, your
site may be unavailable for a few minutes while the route to your
server (or a person browsing) is down. Hickups are more common than
you may think, and are only a real problem if the service does not
restart properly. If KnightGuard catches a hickup anywhere between
itelf and your server, you'll get an alert. That's why sometimes you'll
receive an alert - and a few minutes later check for yourself only
to see that your site is up. That's also why occasional hickups are
nothing to be concerned about.
"Hickups" don't generally last for more than a few minutes,
so you shouldn't expect to receive more than one alert. Also, if you
think your server is hickuping more than usual, it's time to ask your
provider some questions.
Network Congestion / Heavy Server Load
A busy network or server can often give the appearance that your site
is down, or at least unresponsive. This is especially true in Shared
Hosting environments, where you have no control over what other users
are doing on the same server as you are using. If someone is doing
a mass-mailing (for instance) on your server while a browser is surfing
your site, it may look like your Web Site is slow. The same is true
if someone is uploading or downloading a very large file to/from the
same server over a fast connection. If your server is consistently
serving pages slowly, then perhaps it's time to ask your provider
why.
Software (mis)Configuration
It does not happen often, but certain hosting environments seem prone
to configuration errors and mistakes. This could be the result of
changing servers or other hardware, upgrading software, or in the
course of other normal operations. In these cases, you never know
what's going to happen. Your site could be simply slow, or appear
to be gone from the Internet entirely. In either case, you want to
know as soon as possible so you can contact your Technical Support
staff quickly. These are the kinds of events you want to know about
right away, and KnightGuard.Net is always watching.
Hardware Failure
Equipment failures are inevitable; after all, computers and routers
are only collections of electronic components. It is said that the
average mean life expectancy of many electronic components three years.
That means (on average) that each piece of equipment used to serve
up your Web Site will fail within three years. If your site relies
on three devices (there are really more) to serve up web pages, you
can expect about one hardware failure per year to affect service to
your Web Site. Hardware failures can occure in hard disks, memory,
network cards, routers, hubs, switches, etc., all of which your site
relies on to properly present you on the Web.
Redirection
Web Servers commonly use IP port 80 to serve up pages, which is the
port KnightGuard.Net uses to request pages. If your server redirects
the user to a port other than 80, you'll be alerted. Also, KnightGuard.Net
does not support redirects, so the URL you monitor should be the true
server URL, and not be redirected.
False Alarms
Though we firmly believe that if you are alerted there is (was) a
problem, there is always a chance that KnightGuard.Net issued an alert
by accident. After all, we're using the the same technology that you
you are using to serve pages to your customers - and it's prone to
the same failures. However, we do take precautions to try to prevent
false alarms - like doing pre-checks on known reliable servers before
checking your server and testing your site twice before alerting.
We also operate a geographically separate server that performs regular
checks on KnightGuard.Net. If after we determine the problem is likely
with something outside the KnightGuard.Net realm, we'll let you know.
Whether it's a brief or extended outage, we believe you'll want to
know right away. KnightGuard.Net will provide you the first-alert
notification you need to stay in cotrol of your Web Site.
* Technical Note: This is only partialy true. Before
KnightGuard.Net sends an alert, it waits a few seconds and tries the
request again. If the second request fails, you'll be alerted. This
ads a level of fault tollerance to minimize false alarms.)