我有一個非常不穩定的 Apache 伺服器，每天很多次我都很難連接到 apache。我不明白為什麼，因為對我來說一切似乎都很好。伺服器始終擁有「充足」的免費資源。伺服器是 Linode 4098，具有 4GB 記憶體、48GB 硬碟和 2 個 CPU。
我在用著模組狀態檢查 apache 狀態，但當我嘗試存取 /server-status 頁面時，我不斷收到連線逾時錯誤。
我目前的 apache 配置
<IfModule mpm_prefork_module>
StartServers 3
ServerLimit 200
MinSpareServers 3
MaxSpareServers 5
MaxRequestWorkers 175
MaxConnectionsPerChild 100
MaxRequestsPerChild 20
</IfModule>
幾乎每第二個 apache 對 /server-status 的請求都會失敗並出現 ERR_CONNECTION_TIMED_OUT。
我無法理解為什麼會發生這種情況，因為當我檢查伺服器時有大量可用資源和空閒連線。
例如 /server-status 報告許多可用連線：
Parent Server Config. Generation: 1
Parent Server MPM Generation: 0
Server uptime: 1 hour 6 minutes 6 seconds
Server load: 0.09 0.15 0.14
Total accesses: 27206 - Total Traffic: 79.8 MB
CPU Usage: u3.92 s.77 cu0 cs0 - .118% CPU load
6.86 requests/sec - 20.6 kB/second - 3077 B/request
52 requests currently being processed, 1 idle workers
RRRCRRRRRRRRRRRRRRRRRRCRRC.RR.R.RRRRRRRRRCRRRRR_WCCRR.R..RR.....
................................................................
...............................................
透過正常運行時間，我發現 CPU 也可用
load average: 0.05, 0.12, 0.14
並且有可用記憶體：
total used free shared buff/cache available
> Mem: 3.9G 1.3G 413M 81M 2.1G 2.3G
有人知道可能出了什麼問題嗎？
更新：根據要求，這裡是訪問日誌的片段。 （99% 是透過呼叫 /api2/counting/count 腳本處理程序來追蹤統計資料的請求）
4.139.128.194 - - [23/Jan/2017:11:38:36 +0000] "POST /api2/counter/count?r=1485171514298 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
176.38.149.76 - - [23/Jan/2017:11:38:36 +0000] "POST /api2/counter/count?r=1485171517077 HTTP/1.1" 200 454 "-" "WriteDiary4.72"
67.84.227.131 - - [23/Jan/2017:11:38:36 +0000] "GET /keepalive?471:1485171524866 HTTP/1.1" 200 469 "https://www.writediary.com/notes" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393"
122.178.156.252 - - [23/Jan/2017:11:38:36 +0000] "POST /api2/counter/count?r=1485171515804 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
82.137.13.18 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171525558 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
103.199.35.221 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515470 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
95.218.142.245 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171516264 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
47.31.143.106 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515787 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
94.139.128.194 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515619 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
120.188.33.198 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515867 HTTP/1.1" 200 454 "-" "WriteDiary4.72"
47.29.174.163 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515122 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
85.115.224.151 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515453 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
47.11.219.147 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171516596 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
61.5.53.52 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171520665 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
116.102.205.20 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171516590 HTTP/1.1" 200 454 "-" "WriteDiary4.72"
101.60.31.133 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171516802 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
47.31.147.213 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171515431 HTTP/1.1" 200 5131 "-" "WriteDiary4.72"
186.78.73.222 - - [23/Jan/2017:11:38:37 +0000] "POST /api2/counter/count?r=1485171669305 HTTP/1.1" 200 454 "-" "WriteDiary4.72"
112.79.186.36 - - [23/Jan/2017:11:38:38 +0000] "POST /api2/counter/count?r=1485171736857 HTTP/1.1" 200 454 "-" "WriteDiary4.72"
94.139.128.194 - - [23/Jan/2017:11:38:38 +0000] "POST /api2/counter/count?r=1485171516605 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
24.236.88.161 - - [23/Jan/2017:11:38:38 +0000] "POST /api2/counter/count?r=1485171516752 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
150.31.100.192 - - [23/Jan/2017:11:38:38 +0000] "POST /api2/counter/count?r=1485171517315 HTTP/1.1" 200 454 "-" "WriteDiary4.72"
12.181.196.67 - - [23/Jan/2017:11:38:38 +0000] "GET /keepalive?50412:1485171517975 HTTP/1.1" 200 501 "https://www.writediary.com/notes" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36"
112.198.75.139 - - [23/Jan/2017:11:38:38 +0000] "POST /api2/counter/count?r=1485171408169 HTTP/1.1" 200 4794 "-" "WriteDiary4.72"
114.125.201.114 - - [23/Jan/2017:11:38:38 +0000] "POST /api2/counter/count?r=1485172944904 HTTP/1.1" 200 441 "-" "WriteDiary4.72"
解決方案：我必須升級伺服器以允許更多的工作人員。由於每個 Apache 連線需要大約 30MB 或 RAM，伺服器正在突破 4GB RAM 的限制 = 4000MB / 30MB = 最多 133 個連線...並且當部分記憶體分配給 mysql 和其他系統功能時，實際上只有 3.5GB可用，最多可提供接近100 個連線。
升級到 8GB RAM 時，最大限制接近 250 個連接，這使得一切運行順利。事實上，在重新調整 RAM 後，伺服器狀態報告 Apache 在高峰時間同時處理了 200 個請求。這可以解釋為什麼伺服器在高峰時間在限制接近 100 時陷入困境。
答案1
你能發布 apache 訪問日誌嗎
如果您使用 ubuntu，您可以使用此命令來尋找日誌
cat /var/log/apache2/access.log
但它根據您的平台而有所不同