On Feb 9, 2010, at 2:26 PM, Paul Flint wrote: > The answer appears to be that Linux does not cache DNS locally....
I'm curious how this is affects Chromium/Google Chrome performance in Linux versus other platforms, and whether this is actually true. The Chromium documentation implies that there is some internal DNS caching within the network stack across the various OSes. Chromium pre-emptively sends DNS lookups for any links likely to be clicked on the current page, with notable exceptions being SSL links and sites with headers explicitly turning off this functionality using the "X-DNS-Prefetch-Control" attribute. This mechanism is explained in more detail here: http://dev.chromium.org/developers/design-documents/dns-prefetching The idea being that should the link actually be clicked, the DNS request will hit the OS' DNS cache (not one internal to Chromium) without incurring the extra latency of an external lookup.
