Hello! Late to the party. We've seen the same results over here when using sendfile with HTTP/2. You can increase it from 8k to 16 frames using http2_chunk_size but that still won't be good performance when dealing with files that aren't tiny.
Really glad I found this thread, and I appreciate the clarification Maxim. One thing I ponder though, shouldn't it be beneficial to have a directive to toggle Sendfile on/off specifically for HTTP/2? It would be nice to allow a location to Sendfile over HTTP/1.1 by still respond to HTTP/2 requests. Best, Noam Cvikel Qwilt | Delivery Software Engineer | no...@qwilt.com -----Original Message----- From: nginx-devel [mailto:nginx-devel-boun...@nginx.org] On Behalf Of Maxim Dounin Sent: Thursday, December 2, 2021 15:07 To: nginx-devel@nginx.org Subject: Re: nginx KTLS and HTTP/2 performance degradation Hello! On Thu, Dec 02, 2021 at 02:05:52PM +0200, Lyuben Stoev wrote: > Hello, > I have tested the nginx with the patch > https://hg.nginx.org/nginx/rev/65946a191197 (SSL: SSL_sendfile() > support with kernel TLS.) following the nginx blog article > https://www.nginx.com/blog/improving-nginx-performance-with-kernel-tls > / And it sort of works, but I have bad performance when making HTTP/2 > requests. If I made a HTTP/1.1 request there is 30-35% increase in > performance as the Nginx blog article stated, but when I changed the > request to use HTTP/2 the request was 40% slower than an ordinary > nginx without KTLS enabled. Does anyone have such perfomance > degradation with nginx KTLS and HTTP/2? I am using generic setup - > Ubuntu 20.04.3 LTS and kernels 5.8.0-63-generic (the same results are with > 5.4.0-91-generic). > The nginx vritual host is the same as in the Nginx blog article with > exception of adding http2 to the listen! OpenSSL 3.0.0 and nginx > 1.21.4 are used. > The KTLS seems to work, because the strace and debug logs show it. > Just the sstrange thing is when using HTTP2, the sendfile syscalls look: > write(39, "\0 \0\0\0\0\0\0\1", 9) = 9 > sendfile(39, 131, [1418218] => [1426410], 8192) = 8192 > write(39, "\0 \0\0\0\0\0\0\1", 9) = 9 > sendfile(39, 131, [1426410] => [1434602], 8192) = 8192 > write(39, "\0 \0\0\0\0\0\0\1", 9) = 9 > sendfile(39, 131, [1434602] => [1442794], 8192) = 8192 > write(39, "\0 \0\0\0\0\0\0\1", 9) = 9 > sendfile(39, 131, [1442794] => [1450986], 8192) = 8192 > write(39, "\0 \0\0\0\0\0\0\1", 9) = 9 > sendfile(39, 131, [1450986] => [1459178], 8192) = 8192 > write(39, "\0 \0\0\0\0\0\0\1", 9) = 9 > sendfile(39, 131, [1459178] => [1467370], 8192) = 8192 > > It is always 8K and there are thousands of sendfile syscalls.... That's expected, because of HTTP/2 framing. Unfortunately, HTTP/2 isn't designed to work with sendfile(), and sending large files over HTTP/2 require a lot of sendfile() syscalls. In general, for HTTP/2 it is better to keep sendfile() disabled. -- Maxim Dounin http://mdounin.ru/ _______________________________________________ nginx-devel mailing list nginx-devel@nginx.org http://mailman.nginx.org/mailman/listinfo/nginx-devel _______________________________________________ nginx-devel mailing list -- nginx-devel@nginx.org To unsubscribe send an email to nginx-devel-le...@nginx.org
