방문자가 많은 포럼이 있습니다. 언젠가는 방문자 수를 늘리지 않고 40에 도달하기 위해 부하가 증가합니다. 아래 출력에서 볼 수 있듯이 대기 시간이 높습니다 (57 %). 그 이유를 어떻게 찾을 수 있습니까?
서버 소프트웨어는 Apache, MySQL 및 PHP입니다.
root@server:~# top
top - 13:22:08 up 283 days, 22:06, 1 user, load average: 13.84, 24.75, 22.79
Tasks: 333 total, 1 running, 331 sleeping, 0 stopped, 1 zombie
Cpu(s): 20.6%us, 7.9%sy, 0.0%ni, 13.4%id, 57.1%wa, 0.1%hi, 0.9%si, 0.0%st
Mem: 4053180k total, 3868680k used, 184500k free, 136380k buffers
Swap: 9936160k total, 12144k used, 9924016k free, 2166552k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23930 mysql 20 0 549m 122m 6580 S 90 3.1 4449:04 mysqld
17422 www-data 20 0 223m 20m 10m S 2 0.5 0:00.21 apache2
17555 www-data 20 0 222m 19m 9968 S 2 0.5 0:00.13 apache2
17264 www-data 20 0 225m 19m 8972 S 1 0.5 0:00.17 apache2
17251 www-data 20 0 220m 12m 4912 S 1 0.3 0:00.12 apache2
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root@server:~# top
top - 13:39:59 up 283 days, 22:24, 1 user, load average: 6.66, 10.39, 13.95
Tasks: 318 total, 1 running, 317 sleeping, 0 stopped, 0 zombie
Cpu(s): 13.6%us, 4.2%sy, 0.0%ni, 40.5%id, 40.6%wa, 0.2%hi, 0.8%si, 0.0%st
Mem: 4053180k total, 4010992k used, 42188k free, 119544k buffers
Swap: 9936160k total, 12160k used, 9924000k free, 2290716k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23930 mysql 20 0 549m 122m 6580 S 44 3.1 4457:30 mysqld
19946 www-data 20 0 223m 21m 10m S 5 0.6 0:00.77 apache2
17316 www-data 20 0 226m 23m 11m S 1 0.6 0:01.76 apache2
17333 www-data 20 0 222m 21m 11m S 1 0.5 0:01.55 apache2
18212 www-data 20 0 225m 22m 11m S 1 0.6 0:01.58 apache2
19528 www-data 20 0 220m 13m 5480 S 1 0.3 0:00.63 apache2
19600 www-data 20 0 224m 20m 11m S 1 0.5 0:00.73 apache2
19942 www-data 20 0 225m 21m 10m S 1 0.5 0:00.82 apache2
20232 www-data 20 0 222m 16m 8760 S 1 0.4 0:00.65 apache2
20243 www-data 20 0 223m 21m 11m S 1 0.5 0:00.57 apache2
20299 www-data 20 0 225m 20m 9m S 1 0.5 0:00.67 apache2
20441 www-data 20 0 225m 21m 10m S 1 0.5 0:00.57 apache2
21201 www-data 20 0 220m 12m 5148 S 1 0.3 0:00.19 apache2
21362 www-data 20 0 220m 12m 5032 S 1 0.3 0:00.17 apache2
21364 www-data 20 0 220m 12m 4916 S 1 0.3 0:00.14 apache2
21366 www-data 20 0 220m 12m 5124 S 1 0.3 0:00.22 apache2
21373 www-data 20 0 222m 14m 7060 S 1 0.4 0:00.26 apache2