本次测试用到3台服务器:
192.168.10.115:转发服务器A
192.168.10.209:upstream下服务器1
192.168.10.210:upstream下服务器2
1台客户端:192.168.10.112
服务器A中nginx主要配置如下:
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
keepalive_timeout 65;
#gzip on;
upstream testup{
server 192.168.10.209 weight=1 max_fails=1 fail_timeout=30s;
server 192.168.10.210 weight=1 max_fails=1 fail_timeout=30s;
}
server {
listen 80;
server_name localhost;
#charset koi8-r;
access_log logs/host.access.log main;
location / {
#root html;
#index index.html index.htm;
proxy_next_upstream http_502 http_504 error timeout invalid_header;
proxy_ignore_client_abort on;
proxy_send_timeout 60s;
proxy_read_timeout 300s;
proxy_next_upstream_tries 0;
proxy_pass http://testup;
proxy_set_header Host $host:$server_port;
proxy_set_header X-Real-IP $remote_addr;
proxy_connect_timeout 3;
proxy_redirect default;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}
nginx工作进程配置为2,
服务器1和服务器2都是普通的web服务配置不在此展示了
服务器1页面1:
服务器2页面2:
正常访问服务器A会在如上页面1和2之间切换
测试情况1:关闭服务器1
请求A地址,先卡顿差不多3s(应该与'proxy_connect_timeout 3'相关)然后切换成页面2内容,随后刷新无任何卡顿,30s(nginx相关配置:'max_fails=1 fail_timeout=30s')过后再次请求仍会卡顿3s成功随后并不卡顿,nginx报错日志如下:
2024/09/21 18:23:19 [error] 6056#0: *114 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.209:80/", host: "192.168.10.115"
测试情况2:不关闭服务器1,只关闭其nginx服务
请求A地址,不出现卡顿,页面一直显示的页面2内容。nginx报错日志:
2024/09/21 18:30:14 [error] 6055#0: *133 connect() failed (113: No route to host) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.209:80/", host: "192.168.10.115"
2024/09/21 18:30:48 [error] 6055#0: *133 connect() failed (113: No route to host) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.209:80/", host: "192.168.10.115"
此处说明'proxy_connect_timeout 3'针对的是请求能否转达服务器,与目标服务器上的nginx服务是否正常运行无关。
测试情况3:关闭服务器1和2(2选择的是屏蔽了对外端口)
请求A地址,卡顿了差不多6,7s出现如下页面:
此处应该是先后请求了两个服务器耗时3*2s,随后请求不卡顿直接返回如上页面,30s后继续请求仍会卡顿6s随后不卡顿。nginx报错日志:
此处前两条分别是两台服务器的超时日志,后续的日志"no live upstreams while connecting to upstream"是nginx在由于之前请求超时已经判断两台机器都不可用,在30s不会再去转发请求到该服务器,没有了可用的upstreams直接报该错误。
测试情况4:模拟慢网情况
恢复服务器1,2的正常访问,保证访问A地址能正常在页面1,2之前切换。
模拟网络延迟:
tc qdisc add dev ens33 root netem delay 1000ms
参考文档:1分钟学会在Linux下模拟网络延迟_linux模拟网络延迟-CSDN博客
这里将服务器A的nginx配置'proxy_connect_timeout'值改为1。如果喜欢等待的老铁也可以选择不改,但上面的延迟时间要改为3000ms了。这延迟那真的是连xshell连接服务器的输入输出都延迟了╮(╯▽╰)╭,只要是走网卡的应该都会被卡一下。
此时访问A地址,卡顿了一段时间后页面如下:
与之前的关闭服务器1,2的情况大致一样。首次卡顿了4,5s返回如上页面,随后刷新2s返回,过30s后仍会卡顿4,5s返回。错误日志输出情况也与情况3一致。
将服务器A的nginx配置'proxy_connect_timeout'值改为2。继续请求A地址,差不多4,5s返回页面1或页面2,并且页面内容正常切换。
测试情况4.2:调整proxy_next_upstream_tries
在情况4的弱网请求失败情况下,修改'proxy_next_upstream_tries'值为1,请求A地址3次。nginx错误日志:
2024/09/21 21:03:10 [notice] 6399#0: signal process started
2024/09/21 21:03:29 [error] 6401#0: *396 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.209:80/", host: "192.168.10.115"
2024/09/21 21:03:40 [error] 6401#0: *396 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.210:80/", host: "192.168.10.115"
2024/09/21 21:03:49 [error] 6401#0: *396 no live upstreams while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://testup/", host: "192.168.10.115
修改'proxy_next_upstream_tries'值为2,请求A地址2次,错误日志:
2024/09/21 21:23:16 [error] 6432#0: *413 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.209:80/", host: "192.168.10.115"
2024/09/21 21:23:17 [error] 6432#0: *413 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.210:80/", host: "192.168.10.115"
2024/09/21 21:23:22 [error] 6432#0: *413 no live upstreams while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://testup/", host: "192.168.10.115"
相较于上次修改配置,这次请求第一次就连续尝试连接209和210,都失败,归为不可用,第二次请求直接返回"no live upstreams"报错。
再次修改'proxy_next_upstream_tries'值为3,请求A地址2次,错误日志:
2024/09/21 21:28:59 [error] 6446#0: *423 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.209:80/", host: "192.168.10.115"
2024/09/21 21:29:00 [error] 6446#0: *423 upstream timed out (110: Connection timed out) while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://192.168.10.210:80/", host: "192.168.10.115"
2024/09/21 21:29:12 [error] 6446#0: *423 no live upstreams while connecting to upstream, client: 192.168.10.112, server: localhost, request: "GET / HTTP/1.1", upstream: "http://testup/", host: "192.168.10.115"
跟上次测试日志输出一样,upstream下总共就2台服务器,不会因为proxy_next_upstream_tries的值大于2就循环再次请求第一个服务器。所以proxy_next_upstream_tries的值大于转发的服务器的数量时以服务器数量为准。proxy_next_upstream_tries值为0的时候从日志上看应该是按照服务器数量尝试连接的。
测试情况4.3:调整max_fails
配置nginx中max_fails值改为2,请求地址A3次,前两次请求时间明显较长,报错日志:
30s内每个upstream下服务器连接超时2次,才都判定为不可用时,最后一次请求出现"no live upstream"。
至此,想要测试的差不多结束了。
最后测试完记得删除网络延迟:
tc qdisc del dev ens33 root
如果上述测试对您有学习和工作有所帮助就点个赞吧!