[记录]解决 Nginx 在宝塔面板中启动失败的问题分析与解决方案

问题描述：

在使用宝塔面板管理 Nginx 服务过程中，遇到了服务突然停止的问题。日志显示大量的 close() channel failed (9: Bad file descriptor) 以及 worker process exited on signal 9 错误。此外，还出现了 fork() failed while spawning "worker process" (12: Cannot allocate memory)，表明系统内存不足，无法创建新的工作进程。

2024/04/14 03:38:04 [alert] 2341#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:04 [alert] 2341#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:04 [alert] 6197#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:04 [alert] 6193#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:04 [alert] 6199#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:04 [alert] 6192#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:02 [alert] 6238#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:04 [alert] 6239#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:05 [alert] 6238#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:05 [alert] 6239#0: close() channel failed (9: Bad file descriptor)
2024/04/14 03:38:10 [alert] 2341#0: worker process 6238 exited on signal 9
2024/04/14 03:38:20 [alert] 2341#0: worker process 6192 exited on signal 9
2024/04/14 03:38:31 [alert] 2341#0: worker process 6197 exited on signal 9
2024/04/14 03:38:40 [alert] 2341#0: worker process 6346 exited on signal 9
2024/04/14 03:38:51 [alert] 2341#0: worker process 6357 exited on signal 9
2024/04/14 03:39:05 [alert] 2341#0: worker process 6199 exited on signal 9
2024/04/14 03:39:07 [alert] 2341#0: worker process 6311 exited on signal 9
2024/04/14 03:39:14 [alert] 2341#0: worker process 6193 exited on signal 9
2024/04/14 03:39:14 [alert] 2341#0: worker process 6397 exited on signal 9
2024/04/14 03:39:28 [alert] 2341#0: worker process 6239 exited on signal 9
2024/04/14 03:39:28 [alert] 2341#0: worker process 6417 exited on signal 9
2024/04/14 03:39:31 [alert] 2341#0: worker process 6416 exited on signal 9
2024/04/14 03:39:37 [alert] 2341#0: worker process 6423 exited on signal 9
2024/04/14 03:39:39 [alert] 2341#0: worker process 6424 exited on signal 9
2024/04/14 03:39:42 [alert] 2341#0: worker process 6429 exited on signal 9
2024/04/14 03:39:44 [alert] 2341#0: worker process 6330 exited on signal 9
2024/04/14 03:39:44 [alert] 2341#0: worker process 6432 exited on signal 9
2024/04/14 03:39:56 [alert] 2341#0: worker process 6374 exited on signal 9
2024/04/14 03:40:06 [alert] 2341#0: worker process 6486 exited on signal 9
2024/04/14 03:40:20 [alert] 2341#0: worker process 6467 exited on signal 9
2024/04/14 03:42:47 [alert] 2341#0: worker process 6433 exited on signal 9
2024/04/14 03:43:37 [alert] 2341#0: worker process 6523 exited on signal 9
2024/04/14 03:47:58 [alert] 2341#0: worker process 6538 exited on signal 9
2024/04/14 03:48:07 [alert] 2341#0: worker process 6389 exited on signal 9
2024/04/14 03:50:06 [alert] 2341#0: worker process 6463 exited on signal 9
2024/04/14 03:52:28 [alert] 2341#0: worker process 6883 exited on signal 9
2024/04/14 03:53:40 [alert] 2341#0: worker process 7715 exited on signal 9
2024/04/14 03:55:57 [alert] 2341#0: worker process 6970 exited on signal 9
2024/04/14 03:55:57 [alert] 2341#0: fork() failed while spawning ＂worker process＂ (12: Cannot allocate memory)
2024/04/14 03:55:57 [alert] 2341#0: could not respawn worker process
2024/04/14 04:48:32 [alert] 2341#0: worker process 8472 exited on signal 9
2024/04/14 04:48:32 [alert] 2341#0: close() channel failed (9: Bad file descriptor)
2024/04/14 04:48:32 [alert] 2341#0: close() channel failed (9: Bad file descriptor)
2024/04/14 04:48:32 [alert] 2356#0: close() channel failed (9: Bad file descriptor)
2024/04/14 04:48:32 [alert] 7853#0: close() channel failed (9: Bad file descriptor)
2024/04/14 04:48:32 [alert] 7730#0: close() channel failed (9: Bad file descriptor)
2024/04/14 04:48:32 [alert] 8237#0: close() channel failed (9: Bad file descriptor)
2024/04/14 04:48:32 [alert] 6466#0: close() channel failed (9: Bad file descriptor)

问题原因：

1. Nginx防火墙与加速插件冲突：安装的免费防火墙插件和网络加速工具可能与 Nginx 的某些配置或其他插件发生冲突，导致资源管理异常。

2. 文件描述符泄露：频繁的 Bad file descriptor 错误提示可能是因为文件描述符被不当处理或泄露，导致 Nginx 无法正常关闭旧的连接或开启新的连接。

3. 内存不足：Cannot allocate memory 错误表明 Nginx 在尝试创建新的工作进程时，因系统可用内存不足而失败。

解决方案：

1. 卸载或禁用冲突插件：

   • 根据问题描述，首先尝试卸载或禁用 Nginx 的防火墙插件和网络加速工具，观察是否能恢复 Nginx 的正常运行。

   • 如果确定是这些插件导致的冲突，考虑查找其他兼容性更好的插件或更新这些插件到最新版本。

2. 检查和优化内存使用：

   • 通过命令 free -m 检查当前系统的内存使用情况。

   • 如果内存确实不足，尝试增加物理内存或配置交换空间来缓解内存压力。

   • 优化 Nginx 的配置，比如调整 worker_processes 和 worker_connections，减少内存使用。

3. 检查文件描述符限制：

   • 使用 ulimit -n 检查当前的文件描述符限制。

   • 如果数值较低，可以在系统级别增加文件描述符的限制。编辑

     /etc/security/limits.conf

     文件，增加如下配置：

     markdownCopy code* soft nofile 65535
     * hard nofile 65535

   • 重新启动宝塔面板和 Nginx 服务，以应用更改。

4. 查看详细日志：

   • 检查 Nginx 的错误日志（通常位于 /var/log/nginx/error.log），获取更多关于错误的具体信息。

   • 根据日志中的详细错误描述，进一步分析和解决问题。

5. 重新启动 Nginx：

   • 在做出上述更改后，尝试重新启动 Nginx 服务，检查服务是否能够正常运行。

结论

这种类型的错误通常涉及到资源管理和软件冲突。通过逐步排查和应用上述解决方案，通常可以恢复 Nginx 的正常运行并防止未来类似的问题发生。如果问题依旧存在，建议深入查看系统日志或寻求专业技术支持。