On 28 January 2016 15:11:03 GMT+00:00, "Rémy Maucherat" <r...@apache.org> wrote: >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.
I need to check the history (I'm on my phone rather than at my computer) but I think I add the caches to reduce GC churn. They certainly helped when I added them but it is worth revisiting if we should cache them at all. Mark --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
