id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
2018	"Significant amount of ""zero size buf in writer t:1 r:0 f:0... 0000000000000000 0-0 while sending to client"""	sjon.hortensius.net@…		"I have a machine which is behind cloudflare, which limits any variation in clients, but ever since upgrading to 1.19.1 I'm seeing a significant amount of errors ""zero size buf in writer"". It's so bad, I've decided to rollback to 1.19.0

I am unable to reproduce this consistently, it seems pretty random. Here are my significant config options:


{{{
	sendfile		on;
	tcp_nopush		on;
	tcp_nodelay		on;
	client_max_body_size 32k;

	keepalive_timeout 65;

	http2_push_preload on;

	gzip on;
	gzip_types text/css application/javascript text/xml application/octet-stream application/wasm;
	gzip_vary on;

	fastcgi_buffers				256 16k;
	fastcgi_max_temp_file_size	0;
	fastcgi_read_timeout		10s;

	ssl_session_timeout			1d;
	ssl_session_cache			shared:SSL:10m;
	ssl_session_tickets			off;

	ssl_protocols				TLSv1.2 TLSv1.3;
	ssl_ciphers					""ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:TLS-CHACHA20-POLY1305-SHA256:TLS-AES-256-GCM-SHA384:TLS-AES-128-GCM-SHA256"";
	ssl_prefer_server_ciphers	on;

	ssl_ecdh_curve				secp384r1;

	# OCSP stapling
	ssl_stapling				on;
	ssl_stapling_verify			on;
	ssl_trusted_certificate		/etc/ssl/certs/ca-certificates.crt;
	resolver					8.8.8.8 8.8.4.4;

}}}
"	defect	closed	minor		nginx-core	1.19.x	fixed			Linux n0 5.5.8-arch1-1 #1 SMP PREEMPT Fri, 06 Mar 2020 00:57:33 +0000 x86_64 GNU/Linux	"nginx version: nginx/1.19.1
built with OpenSSL 1.1.1g  21 Apr 2020
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --conf-path=/etc/nginx/nginx.conf --sbin-path=/usr/bin/nginx --pid-path=/run/nginx.pid --lock-path=/run/lock/nginx.lock --user=http --group=http --http-log-path=/var/log/nginx/access.log --error-log-path=stderr --http-client-body-temp-path=/var/lib/nginx/client-body --http-proxy-temp-path=/var/lib/nginx/proxy --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-cc-opt='-march=x86-64 -mtune=generic -O2 -pipe -fno-plt -D_FORTIFY_SOURCE=2' --with-ld-opt=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now --with-compat --with-debug --with-file-aio --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_degradation_module --with-http_flv_module --with-http_geoip_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-pcre-jit --with-stream --with-stream_geoip_module --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-threads"