我有一台Ubuntu服务器和一个负载相当高的网站。该服务器:
- 专用于Nginx，使用php-fpm（没有Apache），MySQL位于不同的机器上
- 拥有8GB的内存
- 每秒收到约2000个请求。
根据top命令，每个php-fpm进程消耗约65MB的内存:
空闲内存:
admin@myserver:~$ free -m
total used free shared buffers cached
Mem: 7910 7156 753 0 284 2502
-/+ buffers/cache: 4369 3540
Swap: 8099 0 8099
问题
最近，我遇到了严重的性能问题。响应时间非常长，出现了很多网关超时，在晚上当负载高时，90%的用户只看到“服务器未找到”而不是网站（我似乎无法重现这个问题）
日志
我的Nginx错误日志中充满了以下消息：
2012/07/18 20:36:48 [error] 3451#0: *241904 upstream prematurely closed connection while reading response header from upstream, client: 178.49.30.245, server: example.net, request: request: "GET /readarticle/121430 HTTP/1.1", upstream: "fastcgi://127.0.0.1:9001", host: "example.net", referrer: "http://example.net/articles"
我已经尝试过切换到Unix套接字，但仍然遇到这些错误：
2012/07/18 19:27:30 [crit] 2275#0: *12334 connect() to unix:/tmp/fastcgi.sock failed (2: No such file or directory) while connecting to upstream, client: 84.
237.189.45, server: example.net, request: "GET /readarticle/121430 HTTP/1.1", upstream: "fastcgi://unix:/tmp/fastcgi.sock:", host: "example.net", referrer: "http
://example.net/articles"
同时，php-fpm 日志中充满了这些内容：
[18-Jul-2012 19:23:34] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 75 total children
我试过将给定的参数增加到100，但似乎仍不足。
配置
这是我的当前配置。
php-fpm
listen = 127.0.0.1:9001
listen.backlog = 4096
pm = dynamic
pm.max_children = 130
pm.start_servers = 40
pm.min_spare_servers = 10
pm.max_spare_servers = 40
pm.max_requests = 100
nginx
worker_processes 4;
worker_rlimit_nofile 8192;
worker_priority 0;
worker_cpu_affinity 0001 0010 0100 1000;
error_log /var/log/nginx_errors.log;
events {
multi_accept off;
worker_connections 4096;
}
http {
include mime.types;
default_type application/octet-stream;
access_log off;
sendfile on;
keepalive_timeout 65;
gzip on;
# fastcgi parameters
fastcgi_connect_timeout 120;
fastcgi_send_timeout 180;
fastcgi_read_timeout 1000;
fastcgi_buffer_size 128k;
fastcgi_buffers 4 256k;
fastcgi_busy_buffers_size 256k;
fastcgi_temp_file_write_size 256k;
fastcgi_intercept_errors on;
client_max_body_size 128M;
server {
server_name example.net;
root /var/www/example/httpdocs;
index index.php;
charset utf-8;
error_log /var/www/example/nginx_error.log;
error_page 502 504 = /gateway_timeout.html;
# rewrite rule
location / {
if (!-e $request_filename) {
rewrite ^(.*)$ /index.php?path=$1 last;
}
}
location ~* \.php {
fastcgi_pass 127.0.0.1:9001;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_script_name;
include fastcgi_params;
}
}
}
我将非常感激任何关于如何确定问题以及可以调整哪些参数来解决此问题的建议。或者，也许8GB的RAM对于这种负载来说还不足够？
top截图，似乎不是RAM或CPU的问题，因此最有可能是I/O问题。 - VBart