How not to make an error page (was: OT: www.Amazon.com down?)

Tuc at T-B-O-H.NET ml at t-b-o-h.net
Fri Jun 6 13:58:52 CDT 2008


Maybe they should buy time on their own EC2 if they are short of webservers. :)
The staus page http://status.aws.amazon.com/ shows them "Green and Clean"

			Tuc

> 
> I've no idea what Amazon uses for Load Balancers, but I'm pretty sure
> that error message is the default error message served up by a Netscaler
> LB if no web services are available in the pool...
> 
> -andy
> 
> > -----Original Message-----
> > From: Kevin Day [mailto:toasty at dragondata.com]
> > Sent: Friday, June 06, 2008 11:40 AM
> > To: Lasher, Donn
> > Cc: nanog at nanog.org
> > Subject: How not to make an error page (was: OT: www.Amazon.com down?)
> > 
> > 
> > On Jun 6, 2008, at 1:24 PM, Lasher, Donn wrote:
> > 
> > > Checked, and doublechecked, not just me
> > >
> > > www.amazon.com returns:
> > >
> > > Http/1.1 Service Unavailable
> > >
> > > Anyone have a URL for a network/etc status page, or info on the
> > > outage?
> > > Been that way for a while this morning.
> > >
> > > -donn
> > >
> > >
> > 
> > Even worse, the page they're displaying is actually a HTTP 200
> > response code(OK/no error), with no "Don't cache this" header - which
> > means their error page is considered cacheable by some browsers/
> > proxies. So, you may find users who tried to visit Amazon while they
> > were down are still seeing it down long after they fix it.
> > 
> > Lesson to high profile websites: add these to your error pages so you
> > don't have people complaining you're still down long after you're
> > fixed.
> > 
> > * Don't return a 200 response code. Use 500 or 503. Nothing from 2xx
> > or 4xx.
> > * Add a "Cache-control: no-cache, must-revalidate, max-age=0" header,
> > as well as an "Expires: 0" header for good measure.
> > * If your server is really borked and you can't add headers at all,
> > add '<META HTTP-EQUIV="Pragma" CONTENT="no-cache">' to the <head>
> > section. That's not as good, but helps at least on the browser end.
> > * If possible, add a timestamp to the page somewhere (even if it's in
> > an HTML comment) so you can troubleshoot with users still seeing the
> > error.
> > 
> > -- Kevin
> > 
> 
> 
> 





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