On 1/13/08, Steve Summit scs@eskimo.com wrote:
(Though why the behavior differs for "RD/H" versus "Reference desk/Humanities" is stranger still...)
Well, they're cached separately. Squid is (by design) far from clever enough to insert the "redirected from" line.
Anyway, yeah, I can reproduce this. Return headers are fairly unremarkable:
HTTP/1.0 200 OK Date: Sun, 13 Jan 2008 19:54:28 GMT Server: Apache X-Powered-By: PHP/5.1.2 Content-Language: en Vary: Accept-Encoding,Cookie Cache-Control: private, s-maxage=0, max-age=0, must-revalidate Last-Modified: Sun, 13 Jan 2008 19:50:50 GMT Content-Encoding: gzip Content-Length: 101721 Content-Type: text/html; charset=utf-8 Age: 29338 X-Cache: HIT from sq19.wikimedia.org X-Cache-Lookup: HIT from sq19.wikimedia.org:3128 X-Cache: MISS from sq26.wikimedia.org X-Cache-Lookup: MISS from sq26.wikimedia.org:80 Via: 1.0 sq19.wikimedia.org:3128 (squid/2.6.STABLE16), 1.0 sq26.wikimedia.org:80 (squid/2.6.STABLE16) Connection: close
For the non-stale page:
HTTP/1.0 200 OK Date: Mon, 14 Jan 2008 04:06:32 GMT Server: Apache X-Powered-By: PHP/5.2.1 Content-Language: en Vary: Accept-Encoding,Cookie Cache-Control: private, s-maxage=0, max-age=0, must-revalidate Last-Modified: Mon, 14 Jan 2008 03:25:37 GMT Content-Encoding: gzip Content-Length: 95947 Content-Type: text/html; charset=utf-8 X-Cache: MISS from sq24.wikimedia.org X-Cache-Lookup: HIT from sq24.wikimedia.org:3128 X-Cache: MISS from sq21.wikimedia.org X-Cache-Lookup: MISS from sq21.wikimedia.org:80 Via: 1.0 sq24.wikimedia.org:3128 (squid/2.6.STABLE16), 1.0 sq21.wikimedia.org:80 (squid/2.6.STABLE16) Connection: close
I don't think this has to do with the browser at all, it's just the Squid you get. sq19 gave me an old copy, sq24 had to look it up fresh and so I got a new one. When I visit in Firefox I get (mangled a bit courtesy of Firebug, but still readable):
Date: Sat, 12 Jan 2008 06:40:38 GMT Server: Apache X-Powered-By: PHP/5.2.1 Content-Language: en Vary: Accept-Encoding,Cookie Cache-Control: private, s-maxage=0, max-age=0, must-revalidate Last-Modified: Sat, 12 Jan 2008 06:37:46 GMT Content-Encoding: gzip Content-Length: 96660 Content-Type: text/html; charset=utf-8 Age: 157163 X-Cache: HIT from sq19.wikimedia.org, MISS from sq39.wikimedia.org X-Cache-Lookup: HIT from sq19.wikimedia.org:3128, MISS from sq39.wikimedia.org:80 Via: 1.0 sq19.wikimedia.org:3128 (squid/2.6.STABLE16), 1.0 sq39.wikimedia.org:80 (squid/2.6.STABLE16) Connection: keep-alive
I get it from sq19 again, this time even older (maybe I requested a slightly different URL?). Ctrl-F5 in Firefox gets me the same page consistently from sq19.
Actually, this ties into my last post, doesn't it? Do we purge the URLs of redirects to the edited page? Looking at the code, I very much don't see that anywhere. That would explain a fair percentage of outdated cache hits, if true, given the prevalence of redirects.