pass uses higher cpu than hit

Per Buer perbu at
Thu May 21 08:48:03 CEST 2015

On Wed, May 20, 2015 at 7:20 PM, kioto mitsubisi <reader_1000 at>

> (the worst email quoting I've even seen :-)

The reason why Varnish uses more CPU when pass'ing requests is because it
is a lot more work. A cache hit is delivered directly from (virtual) memory
- in most cases physical memory. So, a cache hit is just a writev() and
that is it, more or less.

With a pass you have to fetch it over the network and that involves another
TCP connection, talking to a remote server, parsing stuff, storing it
memory and then dumping it onto the connection.

So this behavior is expected.

*Per Buer*
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