id summary reporter owner description type status priority milestone component version resolution keywords cc uname nginx_version 2421 proxy_next_upstream_tries might be ignored with upstream keepalive fischerthiebaut@… "there is a bug with proxy_next_upstream_tries, which is ignored if Nginx is under load and the upstream server close the connection prematurely. It seems to only occurs with a connection closed. If too many requests are producing this error, It is possible to bring all the upstreams down for a certain time. Here is a reproducer on docker, but the issue was noticed on debian9/11 as well with nginx 1.10<=1.23.0 https://github.com/tibz7/nginx_next_upstream_retries_bug " enhancement accepted minor nginx-core 1.23.x Linux static01-test 5.13.19-4-pve #1 SMP PVE 5.13.19-8 (Mon, 31 Jan 2022 10:09:37 +0100) x86_64 GNU/Linux " nginx version: nginx/1.23.2 built by gcc 10.2.1 20210110 (Debian 10.2.1-6) built with OpenSSL 1.1.1n 15 Mar 2022 TLS SNI support enabled configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_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-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-cc-opt='-g -O2 -ffile-prefix-map=/data/builder/debuild/nginx-1.23.2/debian/debuild-base/nginx-1.23.2=. -fstack-protector-strong -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie' "