Nginx 不常关注配置

upstream http_backend {
    server 127.0.0.1:8080;

    keepalive 16;
}

server {
    ...

    location /http/ {
        proxy_pass http://http_backend;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        ...
    }
}

keepalive_requests number;
# 通过One keepalive connection的最大请求数，超过这个数，这个连接关闭。有利于单连接的内存释放，不建议配置太大
# 如果后端服务也开启了keepalive,这个值需要小于后端服务的maxkeepalive_request，否则会导致nginx触发502
# 1.19.10之前默认值100,之后版本默认1000
keepalive_time time;
#1.19.10开始新增参数，默认值1h，单个连接在1小时内没达到keepalive_requests，连接也会关闭，指的是非空闲的连接
keepalive_timeout timeout;
# Sets a timeout during which an idle keepalive connection to an upstream server will stay open.空闲连接最长保留时间。
# 如果后端服务开启了keepalive，这里的timeout应该小于后端服务的timeout，否则会导致nginx触发502，因为后端先超时关闭连接了。

Syntax:	proxy_next_upstream error | timeout | invalid_header | http_500 | http_502 | http_503 | http_504 | http_403 | http_404 | http_429 | non_idempotent | off ...;
Default:	
proxy_next_upstream error timeout;
# 一个请求，应该被转发到下一个节点的场景
# error: an error occurred while establishing a connection with the server, passing a request to it, or reading the response header;发生在连接、请求、读取响应过程中的任何错误
# timeout: a timeout has occurred while establishing a connection with the server, passing a request to it, or reading the response header;发生在连接，请求，读取响应任何过程的超时
# non_idempotent(非幂等):默认非幂等方法（POST, LOCK, PATCH）不会将请求转发到另一台server，除非启用这个参数
# off 关闭请求错误重传

Syntax:	proxy_next_upstream_tries number;
Default:	
proxy_next_upstream_tries 0;
Context:	http, server, location
This directive appeared in version 1.7.5.
# 限制重试次数，0代表关闭限制，一直重试

	http{
		limit_req_zone $binary_remote_addr zone=ip_limit:20m rate=5r/s;
		limit_req_log_level error;
		limit_req_status 429;
		server{
			location / {
				limit_req zone=ip_limit;
				proxy_pass http://web;
			}
		}
	}

	limit_req_zone $binary_remote_addr zone=ip_limit:20m rate=5r/s brust=4;

limit_req_zone $binary_remote_addr zone=ip_limit:20m rate=5r/s brust=4 nodelay;

	http{
		limit_conn_zone $binary_remote_addr zone=ip_count:20m;
		server{
			location / {
				limit_conn ip_count 1;
				proxy_pass http://web;
			}
		}
	}
	# 20m nginx worker间共享内存大小

location /download/ {
	limit_rate_after 500k;
	limit_rate 20k;
}