如何解决 Hypnotoad 工作人员故障

Question

我有一个由 Hypnotoad 提供的应用程序，没有反向代理。它有 15 个工作人员，每个允许 2 个客户端。该应用程序通过 hypnotoad 在前台模式下启动。

我在 log/production.log 中看到以下内容：

[Wed Apr  1 16:28:12 2015] [error] Worker 119914 has no heartbeat, restarting.
[Wed Apr  1 16:28:21 2015] [error] Worker 119910 has no heartbeat, restarting.
[Wed Apr  1 16:28:21 2015] [error] Worker 119913 has no heartbeat, restarting.
[Wed Apr  1 16:28:22 2015] [error] Worker 119917 has no heartbeat, restarting.
[Wed Apr  1 16:28:22 2015] [error] Worker 119909 has no heartbeat, restarting.
[Wed Apr  1 16:28:27 2015] [error] Worker 119907 has no heartbeat, restarting.
[Wed Apr  1 16:28:34 2015] [error] Worker 119905 has no heartbeat, restarting.
[Wed Apr  1 16:28:42 2015] [error] Worker 119904 has no heartbeat, restarting.
[Wed Apr  1 16:30:12 2015] [error] Worker 119912 has no heartbeat, restarting.
[Wed Apr  1 16:31:23 2015] [error] Worker 119918 has no heartbeat, restarting.
[Wed Apr  1 16:32:18 2015] [error] Worker 119911 has no heartbeat, restarting.
[Wed Apr  1 16:32:22 2015] [error] Worker 119916 has no heartbeat, restarting.

但是，worker 永远不会重新启动。

当我运行 strace 时，管理器进程似乎正在勇敢地试图杀死（现已过期）工作人员：

Process 119878 attached - interrupt to quit
restart_syscall(<... resuming interrupted call ...>) = 0
kill(119906, SIGKILL)                   = 0
kill(119917, SIGKILL)                   = 0
kill(119905, SIGKILL)                   = 0
kill(119910, SIGKILL)                   = 0
kill(119904, SIGKILL)                   = 0
kill(119914, SIGKILL)                   = 0
kill(119916, SIGKILL)                   = 0
kill(119908, SIGKILL)                   = 0
kill(119913, SIGKILL)                   = 0
kill(119915, SIGKILL)                   = 0
kill(119918, SIGKILL)                   = 0
kill(119912, SIGKILL)                   = 0
kill(119909, SIGKILL)                   = 0
kill(119911, SIGKILL)                   = 0
kill(119907, SIGKILL)                   = 0
stat("/xxx/xxx/xxx/hypnotoad.pid", {st_mode=S_IFREG|0644, st_size=6, ...}) = 0
poll([{fd=4, events=POLLIN|POLLPRI}], 1, 1000) = 0 (Timeout)
kill(119906, SIGKILL)                   = 0
kill(119917, SIGKILL)                   = 0
kill(119905, SIGKILL)                   = 0
kill(119910, SIGKILL)                   = 0
kill(119904, SIGKILL)                   = 0
kill(119914, SIGKILL)                   = 0
kill(119916, SIGKILL)                   = 0
kill(119908, SIGKILL)                   = 0
kill(119913, SIGKILL)                   = 0
kill(119915, SIGKILL)                   = 0
kill(119918, SIGKILL)                   = 0
kill(119912, SIGKILL)                   = 0
kill(119909, SIGKILL)                   = 0
kill(119911, SIGKILL)                   = 0
kill(119907, SIGKILL)                   = 0
stat("/xxx/xxx/xxx/hypnotoad.pid", {st_mode=S_IFREG|0644, st_size=6, ...}) = 0
poll([{fd=4, events=POLLIN|POLLPRI}], 1, 1000^C <unfinished ...>
Process 119878 detached

如何进一步排除故障以确定：

1. 为什么 Hypnotoad 认为它仍然需要杀死不存在 流程？
2. 为什么不开始新的？

Answer 1

“Worker 31842 没有心跳，正在重启”是什么意思？

只要它们接受新连接，所有内置预分叉 Web 服务器的工作进程都会定期向管理器进程发送心跳消息，以表明它们仍在响应。应用程序中的阻塞操作（例如无限循环）可以防止这种情况发生，并会强制受影响的工作人员在超时后重新启动。此超时默认为 20 秒，如果您的应用程序需要，可以使用 Mojo::Server::Prefork 中的属性“heartbeat_timeout”进行扩展。

http://mojolicio.us/perldoc/Mojolicious/Guides/FAQ#What-does-Worker-31842-has-no-heartbeat-restarting-mean