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

* Wil Schultz · * Fri Jun 06 15:26:27 2008

I see a 503 actually.
When down:
iWil:~ wschultz$ curl www.amazon.com
HTTP/1.1 503 Service Unavailable
Server: NS_6.1
Content-Length:62
Connection: close
iWil:~ wschultz$ wget -S www.amazon.com
--12:21:26--  http://www.amazon.com/
           => `index.html'
Resolving www.amazon.com... 72.21.206.5
Connecting to www.amazon.com|72.21.206.5|:80... connected.
HTTP request sent, awaiting response...
  HTTP/1.1 503 Service Unavailable
  Server: NS_6.1
  Content-Length:62
  Connection: close
12:21:26 ERROR 503: Service Unavailable.

-wil
On Jun 6, 2008, at 11:40 AM, Kevin Day wrote:
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