Nginx 尝试代理传递给上游名称

Question

您好，我有以下非常简单的负载配置 balancer/fail：

upstream backend_stream {
    server 192.168.0.130:8080   max_fails=2 fail_timeout=30s;
    server 192.168.0.131:8080   max_fails=2 fail_timeout=30s backup;
}

server {
    listen 443 ssl;
    server_name exmaple.com;

    # SSL stuff

    proxy_ignore_client_abort on;
    proxy_connect_timeout 3s;
    proxy_read_timeout 5s;
    proxy_send_timeout 5s;
    send_timeout 20s;
    proxy_next_upstream_timeout 60s;
    proxy_next_upstream_tries 0;
    proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504 non_idempotent;

    proxy_pass  http://backend_stream;

    access_log /path/to/access.log vhosts_extra;
    error_log /path/to/error.log;
}

以及以下访问日志格式：

log_format vhosts_extra '$host:$server_port $remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" [$upstream_addr - $upstream_response_time] $request_time';

最重要的是最后的部分：[$upstream_addr - $upstream_response_time]。我正在记录选择了哪个上游服务器以及上游服务器的响应是什么。 Nginx docs.

有了这样的配置，我想测试一下它能处理什么流量。为此，我当时使用 Apache Benchmark 命令行工具发送了多个并发请求，如下所示：

ab -T application/json -H 'Authorization: Basic XXX' -p ab_post.json -n 1000 -c 30 https://example.com

我的配置会处理请求一段时间，直到它开始阻塞（没关系，我的应用程序有其限制）。但是当第一台服务器开始超载并且 nginx 必须开始使用备份服务器时，一些奇怪的事情发生了。有时 nginx 试图不将请求传递给上游服务器，而是传递给上游名称！这当然不作为主机存在。 ... [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.051

查看日志片段：

example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:54 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 3.730] 8.783
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:54 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.131:8080 - 3.843] 3.907
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:54 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 3.942] 9.003
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:54 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.131:8080 - 4.044] 4.106
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:55 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 4.125] 9.182
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:55 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.131:8080 - 4.249] 4.309
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:55 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 4.306] 9.372
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:55 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.131:8080 - 4.410] 4.477
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:55 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.001, 4.504] 9.566
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:56 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.131:8080 - 4.583] 4.642
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:56 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 4.707] 9.770
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:56 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.131:8080 - 4.798] 4.860
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:56 +0000] "POST / HTTP/1.0" 200 1183 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 4.884] 9.945
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:56 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.048
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:57 +0000] "POST / HTTP/1.0" 504 176 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.000, 5.002] 10.061
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:57 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.051
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:57 +0000] "POST / HTTP/1.0" 504 176 "-" "ApacheBench/2.3" [192.168.0.130:8080, 192.168.0.131:8080 - 5.001, 5.000] 10.059
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:57 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.001, 0.000] 5.052

有时候真的很努力...

example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:58 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.002, 0.000] 5.050
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:58 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.048
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:58 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.064
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:58 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.001, 0.000] 5.065
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:59 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.001, 0.000] 5.059
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:59 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.062
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:59 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.064
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:59 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.063
example.com:443 12.34.12.34 - - [17/Nov/2016:16:15:59 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.066
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:00 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.001, 0.000] 5.051
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:00 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.055
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:00 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.001, 0.000] 5.066
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:00 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.057
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:00 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.000, 0.000] 5.032
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:01 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.001, 0.000] 5.001
example.com:443 12.34.12.34 - - [17/Nov/2016:16:16:01 +0000] "POST / HTTP/1.0" 502 166 "-" "ApacheBench/2.3" [192.168.0.131:8080, backend_stream - 5.002, 0.000] 5.002

我猜想当所有上游服务器都标记为 "failing" 时会发生这种情况，但这只是一个猜测。我在文档或其他任何地方都找不到有关此类行为的任何信息。

这是正常行为吗？我应该知道它可能会发生，还是我做错了什么？

Nginx 上游enter link description here文档站：

If an error occurs during communication with a server, the request will be passed to the next server, and so on until all of the functioning servers will be tried. If a successful response could not be obtained from any of the servers, the client will receive the result of the communication with the last server.

最糟糕的部分是即时 502 Bad Gateway 响应。

一些环境信息：

nginx version: nginx/1.10.0 (Ubuntu)

Nginx 从默认包存储库安装所有扩展，nginx-extras 包。

Answer 1

我遇到了和你一样的问题，我在this website here上找到了答案。

Upstream name can be seen in the $upstream_addr variable if nginx wasn't able to select an upstream server to connect to because all servers were down as per max_fails/fail_timeout. At the same time the "no live upstreams" error is logged to the error log.

希望对您有所帮助。

Nginx 尝试代理传递给上游名称

Nginx tries to proxy pass to upstream name

webserver

nginx

performance-testing