每周重复发生NGINX 502问题

Question

每周一早上我的（数字海洋）服务器都会关闭并产生502网关错误。它并不总是在完全相同的时间，给予或花费几个小时。我无法诊断问题，但这是我尝试过的：

• 确保盒子安全
• 检查没有正在运行的cron作业
• 已确认没有可疑服务正在运行
• 搜索日志文件以查看是否存在任何可疑行为
• 审核应用程序以检查内存泄漏或其他原因（无）
• 检查是否有足够的内存和磁盘空间

我能找到的唯一可能有用的信息如下：

[ 2016-11-21 02:35:02.0177 1064/7fde41b9e7c0 age/Cor/CoreMain.cpp:891 ]: Watchdog seems to be killed; forcing shutdown of all subprocesses

[ 2016-11-21 02:35:02.0180 1064/7fde3b3ce700 age/Cor/CoreMain.cpp:532 ]: Signal received. Gracefully shutting down... (send signal 2 more time(s) to force shutdown)
2016/11/21 02:35:02 [info] 18431#18431: Using 32768KiB of shared memory for push module in /etc/nginx/nginx.conf:76
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:80 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:443 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:80 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:443 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:80 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:443 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:80 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:443 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:80 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: bind() to 0.0.0.0:443 failed (98: Address already in use)
2016/11/21 02:35:02 [emerg] 18432#18432: still could not bind()
2016/11/21 07:08:09 [info] 941#941: Using 32768KiB of shared memory for push module in /etc/nginx/nginx.conf:76
[ 2016-11-21 07:08:09.3136 1064/7f40eccd47c0 age/Wat/WatchdogMain.cpp:1291 ]: Starting Passenger watchdog...
[ 2016-11-21 07:08:09.3249 1113/7fb32c9647c0 age/Cor/CoreMain.cpp:982 ]: Starting Passenger core...
[ 2016-11-21 07:08:09.3250 1113/7fb32c9647c0 age/Cor/CoreMain.cpp:235 ]: Passenger core running in multi-application mode.
[ 2016-11-21 07:08:09.3282 1113/7fb32c9647c0 age/Cor/CoreMain.cpp:732 ]: Passenger core online, PID 1113
[ 2016-11-21 07:08:09.3586 1125/7fa68d1a57c0 age/Ust/UstRouterMain.cpp:529 ]: Starting Passenger UstRouter...
[ 2016-11-21 07:08:09.3689 1125/7fa68d1a57c0 age/Ust/UstRouterMain.cpp:342 ]: Passenger UstRouter online, PID 1125

正在使用的软件版本：

1. Ubuntu 14.04.5 LTS
2. 的nginx / 1.10.1
3. Phusion Passenger 5.0.30
4. Ruby 2.3.0

服务器在导致此功能的时间内运行良好。任何解决这个问题的方向都将受到赞赏。