How to test the uptime of a webserver?

Redd Vinylene reddvinylene at
Thu Sep 4 18:58:23 UTC 2008

On Sun, Aug 31, 2008 at 4:59 PM, Matthew Seaman <
m.seaman at> wrote:

> Redd Vinylene wrote:
>> On Sun, Aug 31, 2008 at 2:22 AM, Moises Castellanos <m2o7i1 at>
>> wrote:
>>> On Sun, Aug 31, 2008 at 7:05 PM, Redd Vinylene <reddvinylene at>
>>> wrote:
>  I got this dedicated server which is exposed to DDoS attacks quite
>>>> frequently. Say I need to host a website on it, is there any way of
>>>> telling how often it is actually online (to the rest of the world)?
>>>> Maybe make some sort of ping script from a remote server?
>     You can install nagios and monitor the web server. It will send you an
>>> email when
>>> the server is down and when is up again. With this information you can
>>> know
>>> the uptime
>>> of the web server.
>  I'd have to install Nagios on a different server then, right? I doubt
>> the actual server knows when its ISP's link drops (or just slows down)
>> due to an attack.
> Not necessarily.  You can install nagios on your web server and use it
> to monitor a server at the other end of your wan link -- usually a
> machine in your ISPs infrastructure[*] -- on the basis that if you can get
> packets out, then other people can get packets in.  The trick is to monitor
> something that isn't too far away, or you'll end up monitoring the
> availability of other people's networks, rather than your own.
> There's a lot more can be done than just monitoring connectivity by
> sending ICMP ping packets every so often.  There are any number of
> ways a web server can go wrong -- processes can crash, critical disk
> partitions can fill up, load spikes can overwhelm the machine's capacity.
> You can develop a range of different nagios tests that should tell you
> pretty much at a glance just what has gone wrong.  Takes all the fun out
> of diagnosing the problems perhaps, but it does mean you'll be back to
> bed sooner when the pager goes off in the small hours.
>        Cheers,
>        Matthew
> [*] Some ISPs provide machines specifically for this purpose.
> --
> Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
>                                                 Flat 3
> PGP:     Ramsgate
>                                                 Kent, CT11 9PW
Thank you guys. I'm looking for the simplest solution though, like a simple
oneliner, or a shell script.

Anybody have an idea?


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