我在 Magento 商店遇到了一个奇怪的问题。当我们遇到流量高峰时，服务器崩溃了，所以我检查了发生了什么。使用 htop 我发现 PHP5 CGI 在一次点击中占用了高达 100% 的 CPU。我使用的是 vps，但资源应该足以处理一次点击。由于我使用的是 Magento，我认为（希望）它不是写得不好的 PHP，但我真的不知道。我还使用 varnish 作为缓存，因此 Apache 在端口 8080 上运行，但这应该没什么关系。
操作系统是 Ubuntu 12.04.5 LTS
我的问题：我如何才能查明导致这种情况的原因？有什么好的、系统的方法来找出罪魁祸首？
这是我的 Apache 错误日志中的最后几条记录。我没有发现任何异常。
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] Init: Name-based SSL virtual hosts only work for clients with TLS server name indication support (RFC 4366)
[Tue Apr 28 16:38:54 2015] [notice] suEXEC mechanism enabled (wrapper: /usr/lib/apache2/suexec)
[Tue Apr 28 16:38:54 2015] [notice] Digest: generating secret for digest authentication ...
[Tue Apr 28 16:38:54 2015] [notice] Digest: done
[Tue Apr 28 16:38:54 2015] [error] python_init: Python version mismatch, expected '2.7.2+', found '2.7.3'.
[Tue Apr 28 16:38:54 2015] [error] python_init: Python executable found '/usr/bin/python'.
[Tue Apr 28 16:38:54 2015] [error] python_init: Python path being used '/usr/lib/python2.7/:/usr/lib/python2.7/plat-linux2:/usr/lib/python2.7/lib-tk:/usr/lib/python2.7/lib-old:/usr/lib/python2.7/lib-dynload'.
[Tue Apr 28 16:38:54 2015] [notice] mod_python: Creating 8 session mutexes based on 40 max processes and 0 max threads.
[Tue Apr 28 16:38:54 2015] [notice] mod_python: using mutex_directory /tmp
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:38:54 2015] [warn] Init: Name-based SSL virtual hosts only work for clients with TLS server name indication support (RFC 4366)
[Tue Apr 28 16:38:54 2015] [notice] Apache/2.2.22 (Ubuntu) DAV/2 mod_fcgid/2.3.6 mod_python/3.3.1 Python/2.7.3 mod_ssl/2.2.22 OpenSSL/1.0.1 mod_perl/2.0.5 Perl/v5.14.2 configured -- resuming normal operations
[Tue Apr 28 16:39:07 2015] [notice] caught SIGTERM, shutting down
[Tue Apr 28 16:39:09 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:39:09 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:39:09 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:39:09 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:39:09 2015] [warn] RSA server certificate CommonName (CN) `Parallels Panel' does NOT match server name!?
[Tue Apr 28 16:39:09 2015] [warn] Init: Name-based SSL virtual hosts only work for clients with TLS server name indication support (RFC 4366)
[Tue Apr 28 16:39:09 2015] [notice] suEXEC mechanism enabled (wrapper: /usr/lib/apache2/suexec)
[Tue Apr 28 16:39:09 2015] [notice] Digest: generating secret for digest authentication ...
[Tue Apr 28 16:39:09 2015] [notice] Digest: done
这是 $ top 的结果
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
6452 someuser 20 0 323m 78m 9136 R 85 0.5 0:08.91 php5-cgi
6456 someuser 20 0 296m 52m 9144 R 65 0.3 0:07.14 php5-cgi
6454 someuser 20 0 294m 50m 9232 S 62 0.3 0:07.43 php5-cgi
6448 someuser 20 0 0 0 0 Z 49 0.0 0:13.56 php5-cgi <defunct>
6446 someuser 20 0 0 0 0 Z 43 0.0 0:29.30 php5-cgi <defunct>
我可以为您提供更多信息，但目前我不知道从哪里开始寻找。
谢谢！