From owner-freebsd-questions@FreeBSD.ORG Sun Aug 31 14:59:28 2008 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A85011065670 for ; Sun, 31 Aug 2008 14:59:28 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (gate6.infracaninophile.co.uk [IPv6:2001:8b0:151:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id 0F61F8FC0C for ; Sun, 31 Aug 2008 14:59:27 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from happy-idiot-talk.infracaninophile.co.uk (localhost [IPv6:::1]) (authenticated bits=0) by smtp.infracaninophile.co.uk (8.14.2/8.14.2) with ESMTP id m7VExLIX076514; Sun, 31 Aug 2008 15:59:22 +0100 (BST) (envelope-from m.seaman@infracaninophile.co.uk) X-DKIM: Sendmail DKIM Filter v2.7.0 smtp.infracaninophile.co.uk m7VExLIX076514 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infracaninophile.co.uk; s=200708; t=1220194762; bh=K+Ofh7ltMWmeFB 95xAPq3nvPq+TxnhUu+FWEAYPe5d8=; h=Message-ID:Date:From:MIME-Version: To:CC:Subject:References:In-Reply-To:Content-Type:Cc:Content-Type: Date:From:In-Reply-To:Message-ID:Mime-Version:References:To; z=Mes sage-ID:=20<48BAB1C1.8020802@infracaninophile.co.uk>|Date:=20Sun,=2 031=20Aug=202008=2015:59:13=20+0100|From:=20Matthew=20Seaman=20|Organization:=20Infracaninophile|User -Agent:=20Thunderbird=202.0.0.16=20(X11/20080726)|MIME-Version:=201 .0|To:=20Redd=20Vinylene=20|CC:=20Moises=20 Castellanos=20,=20questions@freebsd.org|Subject:= 20Re:=20How=20to=20test=20the=20uptime=20of=20a=20webserver?|Refere nces:=20=09<2620c3260808301722s673f70dkab7590f1ed9e48a4@mail.gmail.com>=2 0|In-R eply-To:=20|X-Enigmail-Version:=200.95.6|Content-Type:=20multipart/signed =3B=20micalg=3Dpgp-sha256=3B=0D=0A=20protocol=3D"application/pgp-si gnature"=3B=0D=0A=20boundary=3D"------------enigB0BE261E4735CEB8961 CF2AF"; b=lXIZLqL/sDqRptG9vW1NP8YhAqa32sMnifunwwIX2a9zXpFVv/nqOzWKa zgxjYuTaiJgX3bEVsQq4PhfBIwQL6+jt5sH0yN3WV6qgnB7OvWzSSPSFreG2WHNzw5O owPwbTiTbecnMGzQ9i0BSDU+sLR5KjT3b/l4GzBF+D3uo/U= Message-ID: <48BAB1C1.8020802@infracaninophile.co.uk> Date: Sun, 31 Aug 2008 15:59:13 +0100 From: Matthew Seaman Organization: Infracaninophile User-Agent: Thunderbird 2.0.0.16 (X11/20080726) MIME-Version: 1.0 To: Redd Vinylene References: <2620c3260808301722s673f70dkab7590f1ed9e48a4@mail.gmail.com> In-Reply-To: X-Enigmail-Version: 0.95.6 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enigB0BE261E4735CEB8961CF2AF" X-Virus-Scanned: ClamAV 0.93.3/8122/Sun Aug 31 02:04:56 2008 on happy-idiot-talk.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VERIFIED,NO_RELAYS autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on happy-idiot-talk.infracaninophile.co.uk Cc: questions@freebsd.org, Moises Castellanos Subject: Re: How to test the uptime of a webserver? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Aug 2008 14:59:28 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigB0BE261E4735CEB8961CF2AF Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Redd Vinylene wrote: > On Sun, Aug 31, 2008 at 2:22 AM, Moises Castellanos = wrote: >> >> On Sun, Aug 31, 2008 at 7:05 PM, Redd Vinylene >> 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 yo= u 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 ge= t=20 packets out, then other people can get packets in. The trick is to monit= or=20 something that isn't too far away, or you'll end up monitoring the=20 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 part= itions 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. --=20 Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW --------------enigB0BE261E4735CEB8961CF2AF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREIAAYFAki6sckACgkQ8Mjk52CukIzeugCfYF2RFcOmDWza0pVOrPRpTF0h jSUAnRVWRhx+VTovrjRdG1nC9kfvVnMx =GhiD -----END PGP SIGNATURE----- --------------enigB0BE261E4735CEB8961CF2AF--