> So, you can improve the caching situation by having your server (or > gateway cache) use appropriate headers on responses.
In a deep analysis of OL cache browser use in firefox using the firefox extension "Page Seed", we found out that Firefox is actually not always using properly the cache browser with OL preseeded tile system, even though the headers are properly set on the http server. The Firefox disk cache hash functions can generate collisions for URLs that differ only slightly, which is the case with preesed tiles image in OL. Example of url in OL: http://server.test.org/myappli/mylayer/14/000/000/002/000/000/000.jpeg http://server.test.org/myappli/mylayer/15/000/000/002/000/000/000.jpeg Due to a URL conflict, the Firefox browser cache can store only one of these resources at a time. Changing the URLs of some resources can fix this problem. Consult the Page Speed documentation for information on how to disambiguate these URLs. We found out that we are facing this kind of FF limitation with OL preseeded layers served thru varnish or Squid More info from: http://code.google.com/speed/page-speed/docs/caching.html#LeverageBrowserCaching Avoid URLs that cause cache collisions in Firefox. The Firefox disk cache hash functions can generate collisions for URLs that differ only slightly, namely only on 8-character boundaries. When resources hash to the same key, only one of the resources is persisted to disk cache; the remaining resources with the same key have to be re-fetched across browser restarts. Thus, if you are using fingerprinting or are otherwise programmatically generating file URLs, to maximize cache hit rate, avoid the Firefox hash collision issue by ensuring that your application generates URLs that differ on more than 8-character boundaries. Claude _______________________________________________ Dev mailing list Dev@openlayers.org http://openlayers.org/mailman/listinfo/dev
