我们都知道一个文件夹文件不宜过多，文件过多，会导致性能下降，那到底怎样算过多呢？
今天板子决定蹂躏下自己的新mac
因本文旨在讨论相同状态下，性能随单目录文件数量变化而发生的变化，所以未做其他特别设置
准备：
Mac Pro （ssd）一台 (安装ubuntu 12.04 虚拟机 LNMP 环境)
5个文件夹，各分别包含1w、5w、10w、50w、100w个同样内容小文件
压测命令：ab -n 10000 -c 100 ‘http://s1.localhost.com/files.php?num=xxx’
files.php：
$num = empty($_GET['num']) ? 10000 : $_GET['num'];
echo file_get_contents("/..filepath../$num/file_".rand(1,$num));
以下是测试结果：
1.1w个文件
Document Path: /files.php?num=10000
Document Length: 2 bytes
Concurrency Level: 100
Time taken for tests: 4.385 seconds
Complete requests: 10000
Failed requests: 0
Write errors: 0
Total transferred: 1500000 bytes
HTML transferred: 20000 bytes
Requests per second: 2280.35 [#/sec] (mean)
Time per request: 43.853 [ms] (mean)
Time per request: 0.439 [ms] (mean, across all concurrent requests)
Transfer rate: 334.04 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.4 0 6
Processing: 3 44 4.5 43 69
Waiting: 3 43 4.5 43 69
Total: 9 44 4.3 43 69
Percentage of the requests served within a certain time (ms)
50% 43
66% 44
75% 45
80% 46
90% 49
95% 52
98% 54
99% 56
100% 69 (longest request)
2. 5w个小文件
Document Path: /files.php?num=50000
Document Length: 2 bytes
Concurrency Level: 100
Time taken for tests: 5.088 seconds
Complete requests: 10000
Failed requests: 0
Write errors: 0
Total transferred: 1500000 bytes
HTML transferred: 20000 bytes
Requests per second: 1965.44 [#/sec] (mean)
Time per request: 50.879 [ms] (mean)
Time per request: 0.509 [ms] (mean, across all concurrent requests)
Transfer rate: 287.91 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.4 0 4
Processing: 5 51 8.2 50 568
Waiting: 5 50 8.2 50 568
Total: 9 51 8.2 50 569
Percentage of the requests served within a certain time (ms)
50% 50
66% 51
75% 52
80% 53
90% 56
95% 58
98% 61
99% 62
100% 569 (longest request)
3. 10w个小文件
Document Path: /files.php?num=100000
Document Length: 2 bytes
Concurrency Level: 100
Time taken for tests: 6.541 seconds
Complete requests: 10000
Failed requests: 0
Write errors: 0
Total transferred: 1500000 bytes
HTML transferred: 20000 bytes
Requests per second: 1528.79 [#/sec] (mean)
Time per request: 65.411 [ms] (mean)
Time per request: 0.654 [ms] (mean, across all concurrent requests)
Transfer rate: 223.94 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.5 0 6
Processing: 11 65 35.7 56 1076
Waiting: 11 65 35.7 56 1076
Total: 17 65 35.9 56 1076
Percentage of the requests served within a certain time (ms)
50% 56
66% 58
75% 60
80% 62
90% 69
95% 119
98% 212
99% 268
100% 1076 (longest request)
4. 50w个小文件
Document Path: /files.php?num=500000
Document Length: 2 bytes
Concurrency Level: 100
Time taken for tests: 19.078 seconds
Complete requests: 10000
Failed requests: 0
Write errors: 0
Total transferred: 1500000 bytes
HTML transferred: 20000 bytes
Requests per second: 524.17 [#/sec] (mean)
Time per request: 190.776 [ms] (mean)
Time per request: 1.908 [ms] (mean, across all concurrent requests)
Transfer rate: 76.78 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.4 0 5
Processing: 9 190 72.0 180 672
Waiting: 9 190 72.0 180 672
Total: 13 190 72.0 180 672
Percentage of the requests served within a certain time (ms)
50% 180
66% 216
75% 236
80% 248
90% 280
95% 304
98% 334
99% 508
100% 672 (longest request)
5.100w个小文件
Document Path: /files.php?num=1000000
Document Length: 2 bytes
Concurrency Level: 100
Time taken for tests: 40.261 seconds
Complete requests: 10000
Failed requests: 0
Write errors: 0
Total transferred: 1500000 bytes
HTML transferred: 20000 bytes
Requests per second: 248.38 [#/sec] (mean)
Time per request: 402.614 [ms] (mean)
Time per request: 4.026 [ms] (mean, across all concurrent requests)
Transfer rate: 36.38 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.7 0 9
Processing: 24 401 91.3 407 726
Waiting: 23 401 91.3 407 726
Total: 29 401 91.3 407 726
Percentage of the requests served within a certain time (ms)
50% 407
66% 440
75% 461
80% 475
90% 512
95% 543
98% 592
99% 620
100% 726 (longest request)
结论：自行参考结果吧，要我说的话，以1w为限吧
什么？你没法在一个目录创建100w个文件？那是另外一个话题了，请自行google： linux inode
感觉不太准确。如果不用rand()函数，直接指定文件名的话，几乎没有差别。
rand 是为了模拟随机的文件访问啦
这个结果，和内核、Nginx配置、PHP配置都有一定关系
是的
就喜欢最后一句”自豪地采用 WordPress”,正好遇到个业务需求,服务器载了1Tb的SSD.根目录下有10个目录,每个都含有10万个子目录.其中内含1万个2Kb的’.json’文件.感觉过于水平.目前存放了实际100G的东西却占了十倍的空间.所以过于碎片还真不是什么好事.