2016-01-28 15:53 GMT+01:00 Mark Thomas <ma...@apache.org>: > On 28/01/2016 14:16, Konstantin Kolinko wrote: > > 2016-01-28 17:04 GMT+03:00 <ma...@apache.org>: > >> Author: markt > >> Date: Thu Jan 28 14:04:00 2016 > >> New Revision: 1727355 > >> > >> URL: http://svn.apache.org/viewvc?rev=1727355&view=rev > >> Log: > >> Switch OutputBuffer to a local Map of C2BConvertors. Loading testing > with HTTP/2 and default Tomcat home page suggests an improvement of a few > percent in throughput. > > > > How much memory is wasted? > > I wouldn't call that memory 'wasted'. I'd call it 'used' to gain > somewhere in the region of a 2% to 4% throughput increase. > > > Every connection (incl. keep-alive ones) will have its own map of > > encoders? Encoders are not reused across different connections? > > Using the same load test as I used for the performance numbers, I see a > retained size of less than 1MB all of which is eligible for GC. There > isn't much reuse in HTTP/2. > > If I switch to HTTP/1.1 and run the same test I end up with ~60 > instances using ~16k. Scale that up to 2000 concurrent connections and > you get ~550k so I am not worried about memory use in this case. > > I didn't measure the performance gain of this change for HTTP/1.1 but > I'd expect there to be some benefit although not as much as HTTP/2 > simply because HTTP/2 uses more concurrency for broadly the same load. > > I have always used local encoders and decoders, nobody ever complained about memory use so it's most likely not a problem.
Rémy
