День добрый.
В логе появляется много ошибок типа:
ignore long locked inactive cache entry 14e633f0cc0c31393f02b8e2845b4133, count:1

Основной конфиг:

user nginx;
worker_processes 8;
worker_rlimit_nofile 819200;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
use epoll;
worker_connections 32768;
multi_accept off;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
# несколько лог форматов
tcp_nopush on;
tcp_nodelay on;
sendfile on; server_tokens off;
proxy_max_temp_file_size 8192m;
large_client_header_buffers 8 32k;
proxy_buffers 8 32k;
proxy_cache_methods GET;
proxy_ignore_client_abort on;
proxy_temp_path /home/.nginx/proxy_temp 1 2;
keepalive_requests 10000;
keepalive_timeout 300s;
# + несколько апстримов
include /etc/nginx/conf.d/*.conf;
# инклуд много стандартных однотипных конфигов
}

Пример стандартного однотипного:

upstream testupstream {
server test.ru max_fails=0 fail_timeout=1;
keepalive 300;
}
proxy_cache_path /home/test/.nginx/cache levels=1:2 keys_zone=test:100m loader_files=1000 loader_threshold=450 inactive=12h;
server {
listen 80;
server_name ~^test\. ;
access_log /var/log/nginx/traffic/user11793.log traffic;
access_log /var/log/nginx/upstream/user11793.log upstream if=$log_upstream;
root /home/test/sync/content;
location / {
try_files $uri @upstream;
}
location @upstream {
proxy_http_version 1.1;
proxy_next_upstream error timeout http_404 http_403 http_502;
proxy_cache_valid 200 24h;
proxy_cache_valid 206 24h;
proxy_cache_valid 404 1m;
proxy_cache_revalidate on;
proxy_cache_lock on;
proxy_cache_lock_timeout 1d;
proxy_cache_use_stale updating error timeout http_502;
proxy_cache test;
proxy_cache_min_uses 1;
proxy_set_header Connection "";
proxy_pass http://testupstream;
}
}


nginx -V
nginx version: nginx/1.9.5
built by gcc 4.8.3 20140911 (Red Hat 4.8.3-9) (GCC)
built with OpenSSL 1.0.1e-fips 11 Feb 2013
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --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 --with-threads --user=nginx --group=nginx --add-module=/builddir/build/BUILD/ngx_devel_kit --add-module=/builddir/build/BUILD/ngx_cache_purge --add-module=/builddir/build/BUILD/headers-more-nginx-module --add-module=/builddir/build/BUILD/set-misc-nginx-module --add-module=/builddir/build/BUILD/redis2-nginx-module --add-module=/builddir/build/BUILD/nginx-vod-module --add-module=/builddir/build/BUILD/lua-nginx-module --with-pcre=/builddir/build/BUILD/pcre --with-http_ssl_module --with-http_realip_module --with-http_addition_module --with-http_sub_module --with-http_stub_status_module --with-http_dav_module --with-http_image_filter_module --with-http_mp4_module --with-http_secure_link_module --with-file-aio --with-http_v2_module --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic'