On Sep 30, 2010, at 20:06, Indranil Chakravorty wrote: > I have been mulling over the feasibility of implementing conditional requests > between the client browser and varnish cache.
You are in luck - that already works. :-) And yes - all common browsers support this. You can combine a short-ish Cache-Control maxage header with a longer cache time in Varnish to get some control of how long content is cached for. - ask First request (get Last-Modified for the next request) ============ [...@embla ~]$ curl -svo/dev/null http://www.pool.ntp.org/en/ * About to connect() to www.pool.ntp.org port 80 (#0) * Trying 207.171.3.6... connected * Connected to www.pool.ntp.org (207.171.3.6) port 80 (#0) > GET /en/ HTTP/1.1 > User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.19.7 > OpenSSL/0.9.8l zlib/1.2.3 > Host: www.pool.ntp.org > Accept: */* > * HTTP 1.0, assume close after body < HTTP/1.0 200 OK < Server: Apache/2.2.3 (Red Hat) mod_apreq2-20051231/2.6.1 mod_perl/2.0.4 Perl/v5.8.8 < X-UA-Compatible: IE=8 < P3P: CP="NOI DEVo TAIo PSAo PSDo OUR IND UNI NAV", policyref="/w3c/p3p.xml" < Last-Modified: Fri, 01 Oct 2010 04:13:06 GMT < Vary: Accept-Encoding < Keep-Alive: timeout=30, max=100 < Content-Type: text/html; charset=utf-8 < Content-Length: 14214 < Date: Fri, 01 Oct 2010 04:14:27 GMT < X-Varnish: 946925222 946924396 < Age: 81 < Via: 1.1 varnish * HTTP/1.0 connection set to keep alive! < Connection: keep-alive < X-Served-By: ntplax2.ntppool.net < X-Cache: HIT < X-Cache-Hits: 298 < { [data not shown] * Connection #0 to host www.pool.ntp.org left intact * Closing connection #0 IMS request ============== [...@embla ~]$ curl -H 'If-Modified-Since: Fri, 01 Oct 2010 04:13:06 GMT' -svo/dev/null http://www.pool.ntp.org/en/ * About to connect() to www.pool.ntp.org port 80 (#0) * Trying 207.171.3.6... connected * Connected to www.pool.ntp.org (207.171.3.6) port 80 (#0) > GET /en/ HTTP/1.1 > User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.19.7 > OpenSSL/0.9.8l zlib/1.2.3 > Host: www.pool.ntp.org > Accept: */* > If-Modified-Since: Fri, 01 Oct 2010 04:13:06 GMT > < HTTP/1.1 304 Not Modified < Date: Fri, 01 Oct 2010 04:14:31 GMT < Via: 1.1 varnish < X-Varnish: 946925256 < Last-Modified: Fri, 01 Oct 2010 04:13:06 GMT < Vary: Accept-Encoding < Connection: keep-alive < X-Served-By: ntplax2.ntppool.net < X-Cache: HIT < X-Cache-Hits: 313 < * Connection #0 to host www.pool.ntp.org left intact * Closing connection #0 _______________________________________________ varnish-dev mailing list [email protected] http://lists.varnish-cache.org/mailman/listinfo/varnish-dev
