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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical 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 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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