Nginx 缓存大小不会超过 344GB
Nginx cache size not growing above 344GB
我在 Ubuntu 18 和 docker 图像 nginx:1.19.10-alpine.
上构建了 Nginx 缓存服务器
Ubuntu下面给出18个磁盘使用详情供参考
ubuntu@host_name:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 126G 0 126G 0% /dev
tmpfs 26G 1.4M 26G 1% /run
/dev/mapper/vg_system-root 193G 8.9G 176G 5% /
tmpfs 126G 0 126G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 126G 0 126G 0% /sys/fs/cgroup
/dev/mapper/vg_data-srv 24T 369G 24T 2% /srv
/dev/sda1 453M 364M 62M 86% /boot
overlay 193G 8.9G 176G 5% /var/lib/docker/overlay2/64_characters_random/merged
tmpfs 26G 0 26G 0% /run/user/1646269961
Docker 容器详细信息
ubuntu@host_name:~$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
contnr_idxyz nginx:1.19.10-alpine "/docker-entrypoint.…" 5 days ago Up 9 hours contnr_name
Nginx配置参考
user@host-name:/srv/mytool/nginx/config$ cat proxy.conf
access_log off;
root /var/log/nginx;
open_log_file_cache max=100;
log_format mytoollogformat
'$time_iso8601 $remote_addr $status $request_time $body_bytes_sent '
'$upstream_cache_status "$request" "$http_user_agent"';
proxy_http_version 1.1;
client_max_body_size 10g;
# R/W timeout for origin server
proxy_read_timeout 15m;
proxy_send_timeout 15m;
# R/W timeout for clients
client_body_timeout 15m;
client_header_timeout 15m;
send_timeout 15m;
# TODO: ssl_stapling and ssl_ciphers
ssl_prefer_server_ciphers on;
ssl_session_cache shared:SSL:10m;
proxy_set_header Connection "";
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-mytool-Cache-Host $scheme://$host;
proxy_redirect off;
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mytool:10m max_size=22000g inactive=180d;
proxy_cache_key $host$uri$is_args$args$slice_range;
proxy_set_header Range $slice_range;
proxy_cache_valid 200 206 2y;
proxy_cache_revalidate on;
add_header X-Cache-Status $upstream_cache_status;
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504 http_429;
已删除服务器块，因为它脱离了当前问题的上下文，也出于安全原因。
让我详细解释一下我的问题。我们有主服务器（proxy_passed 服务器），它有数百 TB 的静态资源文件。当我们设置缓存服务器时，它会填充缓存并很好地从缓存中提供文件。但随着时间的推移注意到缓存大小并没有增加到 344GB 以上
user@host_name:/srv/mytool/nginx$ sudo du -sh ./*
344G ./cache
52K ./config
1004K ./log
user@host_name:/srv/mytool/nginx$
我写了一个脚本来下载大约 500GB 的文件。但它从未将缓存大小增加到 344GB 以上。
目前完成的实验
添加了 max_size=100000g（以及旧值 min_free=1000g）
修改 max_size=22000g（设置小于 /srv 大小的值，即 24TB）
删除 min_free=1000g（假设 min_free 以某种方式清除缓存）
修改
proxy_cache_valid 200 206 1h; 到 proxy_cache_valid 200 206 2y;
对于上述所有实验，在更改配置后，我重新启动了 docker 容器和 运行 通过缓存服务器下载 500GB 文件的脚本。但是尽管缓存大小达到了 380 到 400 GB，但在一个小时内它突然下降到 344GB。
我不知道为什么缓存没有完全填满，即使我已经为 /srv 分配了 24TB
Nginx 有问题吗？我的意思是对于 Nginx 的免费版本可能会有任何限制。我应该使用 Nginx plus。或者配置有误。
任何猜测都会对我有所帮助。提前致谢
更新
What are the soft and hard limits for max open files on the cache server?
$ cat /proc/sys/fs/file-max
26375980
$ ulimit -Hn
1048576
$ ulimit -Sn
1024
have you set limits in your nginx conf using worker_rlimit_nofile?
目前没有worker_rlimit_nofile
的设置
/ # cat /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
keepalive_timeout 65;
#gzip on;
include /etc/nginx/conf.d/*.conf;
}
Do you have anything in the error logs?
低于给出的 filtered/distinct 日志
$ cat /srv/mytool/nginx/log/error.log
2022/01/09 05:56:35 [warn] 22#22: *10 an upstream response is buffered to a temporary file /var/cache/nginx/proxy_temp/1/00/0000000001 while reading upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /dists/58.2.A.0.409/semc/binary-arm/Packages HTTP/1.1", upstream: "https://[IPv6_address]:443/masked_path/Packages", host: "dev.mytool-region.mycompany.com"
2022/01/09 06:09:21 [warn] 22#22: *35 a client request body is buffered to a temporary file /var/cache/nginx/client_temp/0000000006, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "POST /masked_path/all HTTP/1.1", host: "dev.mytool-region.mycompany.com"
2022/01/09 08:19:01 [error] 22#22: *120 etag mismatch in slice response while reading response header from upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", subrequest: "/masked_path/xyz.zip", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/09 18:19:12 [warn] 22#22: *1566 upstream server temporarily disabled while reading response header from upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", upstream: "https://[masked_IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/10 01:23:20 [error] 22#22: *2920 etag mismatch in slice response while reading response header from upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", subrequest: "/masked_path/xyz.zip", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/21 07:43:47 [error] 36#36: *441913 upstream timed out (110: Operation timed out) while SSL handshaking to upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/21 07:46:17 [warn] 37#37: *442070 upstream server temporarily disabled while SSL handshaking to upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
Total 25k rows same as below within 10 days of logs
2022/01/11 05:36:58 [alert] 70#70: ignore long locked inactive cache entry 55a25a5037f198bbec6cd49100bb1b76, count:1
2022/01/11 05:36:58 [alert] 70#70: ignore long locked inactive cache entry e996d5e104f405444a579cd491faf3a8, count:1
2022/01/11 05:36:58 [alert] 70#70: ignore long locked inactive cache entry 394517a8ed8e43949003b3f7538dc471, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry 4f92d3a72f64b7bafdbb3f0b66d8e638, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry be41b259a3e8f9698e0976639883a423, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry 1da19b571ea4bce1428251689f0a7c69, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry 2a4cac0c28ea430e7eef3f808cf1e06f, count:1
2022/01/11 05:37:18 [alert] 70#70: ignore long locked inactive cache entry 53a826f6931cf0f16020bcae100af347, count:1
更新 2：
对 nginx:perl docker 容器进行了相同的尝试。它也没有工作，缓存大小观察到，即使它增长超过 392GB，但在几个小时内突然下降到 344GB。用于启动下面给出的容器的命令
sudo docker run \
--detach \
--restart unless-stopped \
--volume /srv/mytool/nginx/config:/etc/nginx/conf.d:ro \
--volume /srv/mytool/nginx/cache:/var/cache/nginx \
--volume /srv/mytool/nginx/log:/var/log/nginx \
nginx:perl
再次更新
避免docker容器nginx:1.19.10-alpine
并做了简单的 Nginx 配置，如下所示
sudo apt install nginx
systemctl status nginx
$ sudo ufw app list
Available applications:
Nginx Full
Nginx HTTP
Nginx HTTPS
OpenSSH
$ sudo ufw allow 'Nginx Full'
Rules updated
Rules updated (v6)
在/etc/nginx/sites-available
中修改default.conf
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=custom_cache:10m inactive=180d;
upstream origin_server {
server dev.mytool-region.mycompany.com;
}
server {
listen 80 default_server;
listen [::]:80 default_server;
server_name _;
location / {
include proxy_params;
proxy_pass http://origin_server;
}
location ~ ^/(path1|path2|path3|path4)/ {
slice 5m;
proxy_cache custom_cache;
proxy_pass http://origin_server;
proxy_cache_valid 200 206 2y;
add_header X-Proxy-Cache $upstream_cache_status;
}
}
已下载约 ~500GB。它工作正常并且缓存按预期填充
ubuntu@host_name:/var/cache$ sudo du -sh ./*
128K ./apparmor
82M ./apt
4.8M ./debconf
20K ./ldconfig
1.2M ./man
0 ./motd-news
518G ./nginx
4.0K ./pollinate
20K ./snapd
ubuntu@host_name:/var/cache$
但是还是不知道具体原因或者我的配置有什么问题。审判还在进行中。
再试一次
使用旧配置（docker nginx:1.19.10-alpine
并将 proxy_cache_valid 200 206 2y; 移入
location ~ ^/(path1|path2|path3|path4)/ {
但这也行不通。
您可以尝试配置临时缓存目录
proxy_max_temp_file_size
我非常怀疑你的 backend-services 在 nginx 询问他们 'If-Modified-Since'
时回应 'YES'
和您的设置
proxy_cache_revalidate on;
按照预期的方式删除过时的缓存项。这就解释了为什么您的缓存可以增长到 500G 但稍后会减少到 344G
根据documentation，max_size参数是可选的。
not specifying a value allows the cache to grow to use all available
disk space.
删除 max-size 可能会让缓存使用所有可用的 space。尝试编辑 proxy_cache_path 指令并将其删除，在您当前的 conf 中修改为：
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mytool:10m inactive=180d;
nginx 缓存切片的问题是当您配置 5 MB 的缓存切片时。
它最终会在缓存目录中创建切片缓存文件。
可以缓存的文件数量与 keys_zone 大小成正比
keys_zone=mytool:10m
因为我有 10m（10 兆字节）的缓存键，所以它允许最多 71203 个文件。
文件说
In addition, all active keys and information about data are stored in
a shared memory zone, whose name and size are configured by the
keys_zone parameter. One megabyte zone can store about 8 thousand
keys.
As part of commercial subscription, the shared memory zone also stores
extended cache information, thus, it is required to specify a larger
zone size for the same number of keys. For example, one megabyte zone
can store about 4 thousand keys.
因此将 keys_zone 修改为更大的值 keys_zone=mytool:1000m 修复了问题。
您可以观察到 keys_zone=mytool:10m
的缓存文件数在 71203 之后没有增长
user@host_name:/srv/mytool/nginx$ sudo du -sh ./*
326G ./cache
52K ./config
406M ./log
user@host_name:/srv/mytool/nginx$ sudo find cache/ -type f | wc -l
71203
但是通过允许 keys_zone=mytool:1000m
的缓存文件无缝计数，它的大小开始增长
user@host_name:/srv/mytool/nginx$ sudo du -sh ./*
518G ./cache
52K ./config
4.6M ./log
user@host_name:/srv/mytool/nginx$ sudo find cache/ -type f | wc -l
107243
我在 Ubuntu 18 和 docker 图像 nginx:1.19.10-alpine.
上构建了 Nginx 缓存服务器Ubuntu下面给出18个磁盘使用详情供参考
ubuntu@host_name:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 126G 0 126G 0% /dev
tmpfs 26G 1.4M 26G 1% /run
/dev/mapper/vg_system-root 193G 8.9G 176G 5% /
tmpfs 126G 0 126G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 126G 0 126G 0% /sys/fs/cgroup
/dev/mapper/vg_data-srv 24T 369G 24T 2% /srv
/dev/sda1 453M 364M 62M 86% /boot
overlay 193G 8.9G 176G 5% /var/lib/docker/overlay2/64_characters_random/merged
tmpfs 26G 0 26G 0% /run/user/1646269961
Docker 容器详细信息
ubuntu@host_name:~$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
contnr_idxyz nginx:1.19.10-alpine "/docker-entrypoint.…" 5 days ago Up 9 hours contnr_name
Nginx配置参考
user@host-name:/srv/mytool/nginx/config$ cat proxy.conf
access_log off;
root /var/log/nginx;
open_log_file_cache max=100;
log_format mytoollogformat
'$time_iso8601 $remote_addr $status $request_time $body_bytes_sent '
'$upstream_cache_status "$request" "$http_user_agent"';
proxy_http_version 1.1;
client_max_body_size 10g;
# R/W timeout for origin server
proxy_read_timeout 15m;
proxy_send_timeout 15m;
# R/W timeout for clients
client_body_timeout 15m;
client_header_timeout 15m;
send_timeout 15m;
# TODO: ssl_stapling and ssl_ciphers
ssl_prefer_server_ciphers on;
ssl_session_cache shared:SSL:10m;
proxy_set_header Connection "";
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-mytool-Cache-Host $scheme://$host;
proxy_redirect off;
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mytool:10m max_size=22000g inactive=180d;
proxy_cache_key $host$uri$is_args$args$slice_range;
proxy_set_header Range $slice_range;
proxy_cache_valid 200 206 2y;
proxy_cache_revalidate on;
add_header X-Cache-Status $upstream_cache_status;
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504 http_429;
已删除服务器块，因为它脱离了当前问题的上下文，也出于安全原因。
让我详细解释一下我的问题。我们有主服务器（proxy_passed 服务器），它有数百 TB 的静态资源文件。当我们设置缓存服务器时，它会填充缓存并很好地从缓存中提供文件。但随着时间的推移注意到缓存大小并没有增加到 344GB 以上
user@host_name:/srv/mytool/nginx$ sudo du -sh ./*
344G ./cache
52K ./config
1004K ./log
user@host_name:/srv/mytool/nginx$
我写了一个脚本来下载大约 500GB 的文件。但它从未将缓存大小增加到 344GB 以上。
目前完成的实验
添加了 max_size=100000g（以及旧值 min_free=1000g）
修改 max_size=22000g（设置小于 /srv 大小的值，即 24TB）
删除 min_free=1000g（假设 min_free 以某种方式清除缓存）
修改
proxy_cache_valid 200 206 1h; 到 proxy_cache_valid 200 206 2y;
对于上述所有实验，在更改配置后，我重新启动了 docker 容器和 运行 通过缓存服务器下载 500GB 文件的脚本。但是尽管缓存大小达到了 380 到 400 GB，但在一个小时内它突然下降到 344GB。
我不知道为什么缓存没有完全填满，即使我已经为 /srv 分配了 24TB
Nginx 有问题吗？我的意思是对于 Nginx 的免费版本可能会有任何限制。我应该使用 Nginx plus。或者配置有误。
任何猜测都会对我有所帮助。提前致谢
更新
What are the soft and hard limits for max open files on the cache server?
$ cat /proc/sys/fs/file-max
26375980
$ ulimit -Hn
1048576
$ ulimit -Sn
1024
have you set limits in your nginx conf using worker_rlimit_nofile?
目前没有worker_rlimit_nofile
的设置/ # cat /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
keepalive_timeout 65;
#gzip on;
include /etc/nginx/conf.d/*.conf;
}
Do you have anything in the error logs?
低于给出的 filtered/distinct 日志
$ cat /srv/mytool/nginx/log/error.log
2022/01/09 05:56:35 [warn] 22#22: *10 an upstream response is buffered to a temporary file /var/cache/nginx/proxy_temp/1/00/0000000001 while reading upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /dists/58.2.A.0.409/semc/binary-arm/Packages HTTP/1.1", upstream: "https://[IPv6_address]:443/masked_path/Packages", host: "dev.mytool-region.mycompany.com"
2022/01/09 06:09:21 [warn] 22#22: *35 a client request body is buffered to a temporary file /var/cache/nginx/client_temp/0000000006, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "POST /masked_path/all HTTP/1.1", host: "dev.mytool-region.mycompany.com"
2022/01/09 08:19:01 [error] 22#22: *120 etag mismatch in slice response while reading response header from upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", subrequest: "/masked_path/xyz.zip", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/09 18:19:12 [warn] 22#22: *1566 upstream server temporarily disabled while reading response header from upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", upstream: "https://[masked_IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/10 01:23:20 [error] 22#22: *2920 etag mismatch in slice response while reading response header from upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", subrequest: "/masked_path/xyz.zip", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/21 07:43:47 [error] 36#36: *441913 upstream timed out (110: Operation timed out) while SSL handshaking to upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
2022/01/21 07:46:17 [warn] 37#37: *442070 upstream server temporarily disabled while SSL handshaking to upstream, client: masked_IPv6_address, server: dev.mytool-region.mycompany.com, request: "GET /masked_path/xyz.zip HTTP/1.1", upstream: "https://[IPv6_address]:443/masked_path/xyz.zip", host: "dev.mytool-region.mycompany.com"
Total 25k rows same as below within 10 days of logs
2022/01/11 05:36:58 [alert] 70#70: ignore long locked inactive cache entry 55a25a5037f198bbec6cd49100bb1b76, count:1
2022/01/11 05:36:58 [alert] 70#70: ignore long locked inactive cache entry e996d5e104f405444a579cd491faf3a8, count:1
2022/01/11 05:36:58 [alert] 70#70: ignore long locked inactive cache entry 394517a8ed8e43949003b3f7538dc471, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry 4f92d3a72f64b7bafdbb3f0b66d8e638, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry be41b259a3e8f9698e0976639883a423, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry 1da19b571ea4bce1428251689f0a7c69, count:1
2022/01/11 05:37:08 [alert] 70#70: ignore long locked inactive cache entry 2a4cac0c28ea430e7eef3f808cf1e06f, count:1
2022/01/11 05:37:18 [alert] 70#70: ignore long locked inactive cache entry 53a826f6931cf0f16020bcae100af347, count:1
更新 2： 对 nginx:perl docker 容器进行了相同的尝试。它也没有工作，缓存大小观察到，即使它增长超过 392GB，但在几个小时内突然下降到 344GB。用于启动下面给出的容器的命令
sudo docker run \
--detach \
--restart unless-stopped \
--volume /srv/mytool/nginx/config:/etc/nginx/conf.d:ro \
--volume /srv/mytool/nginx/cache:/var/cache/nginx \
--volume /srv/mytool/nginx/log:/var/log/nginx \
nginx:perl
再次更新
避免docker容器nginx:1.19.10-alpine 并做了简单的 Nginx 配置，如下所示
sudo apt install nginx
systemctl status nginx
$ sudo ufw app list
Available applications:
Nginx Full
Nginx HTTP
Nginx HTTPS
OpenSSH
$ sudo ufw allow 'Nginx Full'
Rules updated
Rules updated (v6)
在/etc/nginx/sites-available
中修改default.confproxy_cache_path /var/cache/nginx levels=1:2 keys_zone=custom_cache:10m inactive=180d;
upstream origin_server {
server dev.mytool-region.mycompany.com;
}
server {
listen 80 default_server;
listen [::]:80 default_server;
server_name _;
location / {
include proxy_params;
proxy_pass http://origin_server;
}
location ~ ^/(path1|path2|path3|path4)/ {
slice 5m;
proxy_cache custom_cache;
proxy_pass http://origin_server;
proxy_cache_valid 200 206 2y;
add_header X-Proxy-Cache $upstream_cache_status;
}
}
已下载约 ~500GB。它工作正常并且缓存按预期填充
ubuntu@host_name:/var/cache$ sudo du -sh ./*
128K ./apparmor
82M ./apt
4.8M ./debconf
20K ./ldconfig
1.2M ./man
0 ./motd-news
518G ./nginx
4.0K ./pollinate
20K ./snapd
ubuntu@host_name:/var/cache$
但是还是不知道具体原因或者我的配置有什么问题。审判还在进行中。
再试一次
使用旧配置（docker nginx:1.19.10-alpine
并将 proxy_cache_valid 200 206 2y; 移入
location ~ ^/(path1|path2|path3|path4)/ {
但这也行不通。
您可以尝试配置临时缓存目录
proxy_max_temp_file_size
我非常怀疑你的 backend-services 在 nginx 询问他们 'If-Modified-Since'
时回应 'YES'和您的设置
proxy_cache_revalidate on;
按照预期的方式删除过时的缓存项。这就解释了为什么您的缓存可以增长到 500G 但稍后会减少到 344G
根据documentation，max_size参数是可选的。
not specifying a value allows the cache to grow to use all available disk space.
删除 max-size 可能会让缓存使用所有可用的 space。尝试编辑 proxy_cache_path 指令并将其删除，在您当前的 conf 中修改为：
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mytool:10m inactive=180d;
nginx 缓存切片的问题是当您配置 5 MB 的缓存切片时。
它最终会在缓存目录中创建切片缓存文件。
可以缓存的文件数量与 keys_zone 大小成正比
keys_zone=mytool:10m
因为我有 10m（10 兆字节）的缓存键，所以它允许最多 71203 个文件。
文件说
In addition, all active keys and information about data are stored in a shared memory zone, whose name and size are configured by the keys_zone parameter. One megabyte zone can store about 8 thousand keys.
As part of commercial subscription, the shared memory zone also stores extended cache information, thus, it is required to specify a larger zone size for the same number of keys. For example, one megabyte zone can store about 4 thousand keys.
因此将 keys_zone 修改为更大的值 keys_zone=mytool:1000m 修复了问题。
您可以观察到 keys_zone=mytool:10m
user@host_name:/srv/mytool/nginx$ sudo du -sh ./*
326G ./cache
52K ./config
406M ./log
user@host_name:/srv/mytool/nginx$ sudo find cache/ -type f | wc -l
71203
但是通过允许 keys_zone=mytool:1000m
user@host_name:/srv/mytool/nginx$ sudo du -sh ./*
518G ./cache
52K ./config
4.6M ./log
user@host_name:/srv/mytool/nginx$ sudo find cache/ -type f | wc -l
107243