为什么 ab 出现错误：apr_socket_recv: Connection reset by peer (54) on OSX？

Question

我正在尝试使用ab4 个运行的 ubuntu 机器集群进行基准测试nginx，这些机器由另一个正在运行的 ubuntu 机器负载平衡haproxy。对于那些感兴趣的人，我正在关注sysadmincasts教程系列。我无法从运行 osx 的笔记本电脑上成功地对集群进行基准测试：

?  ~ uname -a
Darwin mbp 15.6.0 Darwin Kernel Version 15.6.0: Mon Aug 29 20:21:34 PDT 2016; root:xnu-3248.60.11~1/RELEASE_X86_64 x86_64
?  ~ system_profiler SPSoftwareDataType
Software:

    System Software Overview:

      System Version: OS X 10.11.6 (15G1004)
      Kernel Version: Darwin 15.6.0
      Boot Volume: Untitled
      Boot Mode: Normal
      Computer Name: Max’s MacBook Pro
      User Name: Max Bigras (max)
      Secure Virtual Memory: Enabled
      System Integrity Protection: Disabled
      Time since boot: 4 days 6:27
?  ~ ab -n 10000 -c 25 http://127.0.0.1:8080/
This is ApacheBench, Version 2.3 <$Revision: 1706008 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
apr_socket_recv: Connection reset by peer (54)

我发现另一篇文章提到了osx 中套接字限制问题的可能性。但是，当我尝试提到的解决方案时，它仍然不起作用：

?  ~ sysctl kern.maxfiles
kern.maxfiles: 1048600
?  ~ ulimit -S -n
1048576
?  ~ ab -n 10000 -c 25 http://127.0.0.1:8080/
This is ApacheBench, Version 2.3 <$Revision: 1706008 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
apr_socket_recv: Connection reset by peer (54)
Total of 25 requests completed

我知道我至少会访问我的服务器，因为我检查了正在运行的 Web 节点之一的日志文件 nginx

SSH 到 web1（运行 nginx 的 ubuntu 机器）：

vagrant@web1:~$ echo $USER
vagrant
vagrant@web1:~$ sudo tail -f /var/log/nginx/access.log
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:53:25 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:54:59 +0000] "GET / HTTP/1.0" 200 632 "-" "ApacheBench/2.3"
10.0.15.11 - - [02/Oct/2016:06:55:09 +0000] "GET / HTTP/1.1" 200 632 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36"

ab在 osx 上重试：

?  ~ echo $USER
max
?  ~ date
Sat Oct  1 23:54:54 PDT 2016
?  ~ ab -n 10000 -c 25 http://127.0.0.1:8080/
This is ApacheBench, Version 2.3 <$Revision: 1706008 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
apr_socket_recv: Connection reset by peer (54)
Total of 41 requests completed
?  ~ date
Sat Oct  1 23:55:02 PDT 2016
?  ~

在上面你可以看到，除了尝试对集群进行基准测试之外，我还用我的浏览器点击了它，如/var/log/nginx/access.log. 看起来问题肯定是我可以提出的请求数量有限制。如果我降低请求数量和并发值，那么它可以工作：

?  ~ ab -n 100 -c 1 http://127.0.0.1:8080/
This is ApacheBench, Version 2.3 <$Revision: 1706008 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient).....done


Server Software:        nginx
Server Hostname:        127.0.0.1
Server Port:            8080

Document Path:          /
Document Length:        632 bytes

Concurrency Level:      1
Time taken for tests:   0.218 seconds
Complete requests:      100
Failed requests:        0
Total transferred:      83800 bytes
HTML transferred:       63200 bytes
Requests per second:    458.17 [#/sec] (mean)
Time per request:       2.183 [ms] (mean)
Time per request:       2.183 [ms] (mean, across all concurrent requests)
Transfer rate:          374.95 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.3      0       2
Processing:     1    2   0.8      2       5
Waiting:        1    2   0.7      1       5
Total:          1    2   0.9      2       6
WARNING: The median and mean for the waiting time are not within a normal deviation
        These results are probably not that reliable.

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      3
  95%      4
  98%      6
  99%      6
 100%      6 (longest request)

那么如何配置 osx 以便我可以使用 25 个并发测试 10000 个请求ab？

编辑：添加 nginx.conf

vagrant@web1:~$ cat /etc/nginx/nginx.conf
# Ansible managed: /home/vagrant/templates/nginx.conf.j2 modified on 2016-09-11 14:17:19 by vagrant on mgmt
user              www-data;

worker_processes  1;
pid        /var/run/nginx.pid;
worker_rlimit_nofile 1024;

events {
    worker_connections  512;
}


http {

        include /etc/nginx/mime.types;
        default_type application/octet-stream;
        tcp_nopush "on";
        tcp_nodelay "on";
        #keepalive_timeout "65";
        access_log "/var/log/nginx/access.log";
        error_log "/var/log/nginx/error.log";
        server_tokens off;
        types_hash_max_size 2048;

        # https://philio.me/backend-server-host-name-as-a-custom-header-with-nginx/
        add_header X-Backend-Server $hostname;

        # disable cache used for testing
        add_header Cache-Control private;
        add_header Last-Modified "";
        sendfile off;
        expires off;
        etag off;

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}

Answer 1

该Connection reset by peer错误意味着您的网络服务器在响应您的请求之前关闭了连接。因此，负载对于您的服务器来说太大，并且开始断开连接。

您需要研究您的服务器设置以了解为什么会发生这种情况。研究你的日志文件。

由于您的客户端，不会发生此错误。