python - Django apache 与内置开发服务器的显着开销

Question

我正在即将成为生产环境的 Django/Tastypie 上运行，但是我注意到使用 Apache 与使用内置开发服务器相比开销很大。 Apache 慢得多。

以下是使用 ab 的非科学带宽测试:

Apache :

$ ab -n 100 -c 50 https://www.mydomain.com/api/v1/clock/?format=json
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking www.mydomain.com (be patient).....done


Server Software:        Apache/2.2.22
Server Hostname:        www.mydomain.com
Server Port:            443
SSL/TLS Protocol:       TLSv1/SSLv3,AES256-SHA,2048,256

Document Path:          /api/v1/clock/?format=json
Document Length:        295 bytes

Concurrency Level:      50
Time taken for tests:   1.313 seconds
Complete requests:      100
Failed requests:        0
Write errors:           0
Non-2xx responses:      100
Total transferred:      49800 bytes
HTML transferred:       29500 bytes
Requests per second:    76.15 [#/sec] (mean)
Time per request:       656.634 [ms] (mean)
Time per request:       13.133 [ms] (mean, across all concurrent requests)
Transfer rate:          37.03 [Kbytes/sec] received

Connection Times (ms)
min  mean[+/-sd] median   max
Connect:       15  283 162.5    282     590
Processing:    55  324 148.4    306     622
Waiting:       55  319 150.2    305     621
Total:        110  607 138.8    619     712

Percentage of the requests served within a certain time (ms)
50%    619
66%    691
75%    692
80%    701
90%    709
95%    709
98%    711
99%    712
100%    712 (longest request)

开发服务器(manage.py runserver):

$ ab -n 100 -c 50 http://127.0.0.1:8000/api/v1/clock/?format=json
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
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:        WSGIServer/0.1
Server Hostname:        127.0.0.1
Server Port:            8000

Document Path:          /api/v1/clock/?format=json
Document Length:        381 bytes

Concurrency Level:      50
Time taken for tests:   0.701 seconds
Complete requests:      100
Failed requests:        0
Write errors:           0
Total transferred:      54500 bytes
HTML transferred:       38100 bytes
Requests per second:    142.59 [#/sec] (mean)
Time per request:       350.656 [ms] (mean)
Time per request:       7.013 [ms] (mean, across all concurrent requests)
Transfer rate:          75.89 [Kbytes/sec] received

Connection Times (ms)
min  mean[+/-sd] median   max
Connect:        0    1   1.9      0       7
Processing:    43   73  47.0     63     365
Waiting:       31   70  47.0     61     365
Total:         50   74  47.0     64     365

Percentage of the requests served within a certain time (ms)
50%     64
66%     67
75%     69
80%     71
90%     77
95%    101
98%    276
99%    365
100%    365 (longest request)

如您所见，在较小的负载下，开发服务器的速度大约快 10 倍。即使在更高的负载下，它处理的请求也是原来的两倍。

我已经对 Apache 进行了基本修改以尝试解决这个问题，这似乎有点帮助，但是还有什么我遗漏的吗？我请求的“时钟”是一个非常基本的脚本，带有一个直接的数据库调用，因此连接或任何事情都没有什么奇怪的。它使用 Tastypie，因此输出为纯文本/json。似乎有些不对劲，因为开发服务器的请求速度要快得多。

这是我的 Apache 设置。它是在守护进程模式下在 worker MPM 上设置的:

KeepAlive Off

<IfModule mpm_worker_module>
    StartServers         25
    MinSpareThreads      25
    MaxSpareThreads     300
    ThreadLimit          64
    ThreadsPerChild      25
    MaxClients          300
    MaxRequestsPerChild   0
</IfModule>

WSGIRestrictEmbedded On

虚拟主机添加:

    WSGIDaemonProcess www.mydomain.com processes=4 threads=1
    WSGIProcessGroup www.mydomain.com
    WSGIScriptAlias / /var/www/domain/wsgi.py process-group=www.mydomain.com application-group=%{GLOBAL}
    WSGIPassAuthorization On

Python/Tastypie 设置:

Debug = False
USE_I18N = False
USE_X_FORWARDED_HOST = True

它在负载均衡的 AWS 中型实例上运行，并且该服务器不提供任何静态文件，例如 images/css/js。我尝试在 IOPS/x-large 实例上提高它，但没有任何变化。数据库位于 Amazon RDS 上。但是在运行开发服务器时所有这些都是一样的，这告诉我托管环境不是问题。

任何帮助将不胜感激!!我现在真的不太担心高负载。这是一个基于 JSON 的 API，因此所有请求都是文本并且非常小。我最关心的是大量小请求的响应时间。

谢谢!标记

编辑:

我在 apache 上做了一个新的 ab 测试，将 dns 映射到本地主机。这与将其映射到 127.0.0.1 基本相同。这提供了更好的结果:

$ ab -n 100 -c 50 http://www.mydomain.com/api/v1/clock/?format=json
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking www.mydomain.com (be patient).....done


Server Software:        Apache/2.2.22
Server Hostname:        www.mydomain.com
Server Port:            80

Document Path:          /api/v1/clock/?format=json
Document Length:        381 bytes

Concurrency Level:      50
Time taken for tests:   0.666 seconds
Complete requests:      100
Failed requests:        0
Write errors:           0
Total transferred:      55900 bytes
HTML transferred:       38100 bytes
Requests per second:    150.22 [#/sec] (mean)
Time per request:       332.841 [ms] (mean)
Time per request:       6.657 [ms] (mean, across all concurrent requests)
Transfer rate:          82.01 [Kbytes/sec] received

Connection Times (ms)
min  mean[+/-sd] median   max
Connect:        0    3   3.0      2       6
Processing:    38  258  92.6    308     357
Waiting:       33  254  92.9    303     354
Total:         44  261  90.6    310     363

Percentage of the requests served within a certain time (ms)
50%    310
66%    321
75%    323
80%    327
90%    336
95%    344
98%    362
99%    363
100%    363 (longest request)

所以最初的测试是通过外部负载均衡器进行的。这些数字还可以，但是前 50% 的测试平均响应时间仍为 310 毫秒。这些似乎可以与我的实时外部测试相媲美。然而，django 开发服务器前 50% 的测试平均耗时 64 毫秒，尽管 apache 服务器的扩展性要好得多。是否有任何建议来调整 apache，以便它可以更快地进入为初始请求提供服务的范围？我不介意使用额外的服务器进行水平扩展，但请求时间对我来说意味着一切。

Answer 1

您是否考虑过使用 NGINX？它让我们在使用 uwsgi 运行时有显着的性能提升。