application_start 意外触发 asp.net答案

【问题标题】：application_start firing unexpectedly asp.netapplication_start 意外触发 asp.net
【发布时间】：2010-10-07 05:48:10
【问题描述】：

我正在查看一个 asp.net 应用程序，该应用程序在 global.asax 内部开始调用应用程序内的数据库。这些调用运行大约需要 3 秒（取决于 SQL 缓存计划）。当我第一次重新部署时，我注意到应用程序运行缓慢。我把它归结为应用程序启动时对数据库的调用。然而，几分钟后，应用程序再次需要时间来加载。

为了了解发生了什么，我已经写入了一个日志文件（见下文）。从这个文件中，您可以看到当多个请求第一次命中应用程序时，应用程序启动会多次触发。然后似乎 application_start 以随机方式触发（2-10分钟内的任何时间）。

根据我对 application_starts 工作原理的理解，它应该只在应用程序 FIRST 启动时触发，但它似乎是从多个客户端随机触发的！根据 MSDN “应用程序启动时第一次触发 Application_Start 事件。”

谁能帮我弄清楚发生了什么？我正在使用 IIS6 和 .net 2.0。这是我缺少的应用程序池设置吗？

非常感谢瑞波

[12/02/2009 16:16:58] 91.84.25.241 - Application started, Sub MyRules started
[12/02/2009 16:17:06] 65.55.51.34 - Application started, Sub MyRules started
[12/02/2009 16:17:07] 91.84.25.241 - Application started, Sub MyRules completed
[12/02/2009 16:17:10] 65.55.51.34 - Application started, Sub MyRules completed
[12/02/2009 16:17:26] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:30] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:17:30] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:33] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:17:33] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:36] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:17:36] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:39] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:17:42] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:48] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:17:48] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:52] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:17:52] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:17:54] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:18:27] 91.84.25.241 - Application started, Sub MyRules started
[12/02/2009 16:18:31] 91.84.25.241 - Application started, Sub MyRules completed
[12/02/2009 16:18:31] 212.115.51.229 - Application started, Sub MyRules started
[12/02/2009 16:18:33] 212.115.51.229 - Application started, Sub MyRules completed
[12/02/2009 16:29:26] 167.230.38.115 - Application started, Sub MyRules started
[12/02/2009 16:29:28] 167.230.38.115 - Application started, Sub MyRules completed
[12/02/2009 16:29:34] 82.110.42.84 - Application started, Sub MyRules started
[12/02/2009 16:29:37] 82.110.42.84 - Application started, Sub MyRules completed
[12/02/2009 16:29:38] 82.110.42.84 - Application started, Sub MyRules started
[12/02/2009 16:29:41] 82.110.42.84 - Application started, Sub MyRules completed
[12/02/2009 16:32:53] 99.142.1.97 - Application started, Sub MyRules started
[12/02/2009 16:32:57] 99.142.1.97 - Application started, Sub MyRules completed
[12/02/2009 16:32:57] 99.142.1.97 - Application started, Sub MyRules started
[12/02/2009 16:33:01] 99.142.1.97 - Application started, Sub MyRules completed
[12/02/2009 16:33:01] 99.142.1.97 - Application started, Sub MyRules started
[12/02/2009 16:33:06] 99.142.1.97 - Application started, Sub MyRules completed
[12/02/2009 16:33:06] 99.142.1.97 - Application started, Sub MyRules started
[12/02/2009 16:33:10] 99.142.1.97 - Application started, Sub MyRules completed
[12/02/2009 16:33:11] 99.142.1.97 - Application started, Sub MyRules started
[12/02/2009 16:33:16] 99.142.1.97 - Application started, Sub MyRules completed
[12/02/2009 16:36:15] 65.55.51.34 - Application started, Sub MyRules started
[12/02/2009 16:36:17] 65.55.51.34 - Application started, Sub MyRules completed
[12/02/2009 16:41:37] 119.123.226.156 - Application started, Sub MyRules started
[12/02/2009 16:41:37] 62.49.121.122 - Application started, Sub MyRules started
[12/02/2009 16:41:40] 62.49.121.122 - Application started, Sub MyRules completed
[12/02/2009 16:41:40] 119.123.226.156 - Application started, Sub MyRules completed
[12/02/2009 16:41:41] 62.49.121.122 - Application started, Sub MyRules started
[12/02/2009 16:41:44] 62.49.121.122 - Application started, Sub MyRules completed
[12/02/2009 16:45:17] 84.70.249.242 - Application started, Sub MyRules started
[12/02/2009 16:45:19] 84.70.249.242 - Application started, Sub MyRules completed
[12/02/2009 16:47:03] 80.41.121.68 - Application started, Sub MyRules started
[12/02/2009 16:47:05] 80.41.121.68 - Application started, Sub MyRules completed
[12/02/2009 16:47:29] 81.179.26.249 - Application started, Sub MyRules started
[12/02/2009 16:47:31] 81.179.26.249 - Application started, Sub MyRules completed
[12/02/2009 16:47:59] 81.136.179.170 - Application started, Sub MyRules started
[12/02/2009 16:47:59] 81.136.179.170 - Application started, Sub MyRules started
[12/02/2009 16:48:02] 81.136.179.170 - Application started, Sub MyRules completed
[12/02/2009 16:48:02] 81.136.179.170 - Application started, Sub MyRules started
[12/02/2009 16:48:02] 81.136.179.170 - Application started, Sub MyRules completed
[12/02/2009 16:48:02] 81.136.179.170 - Application started, Sub MyRules started
[12/02/2009 16:48:04] 81.136.179.170 - Application started, Sub MyRules completed
[12/02/2009 16:48:04] 81.136.179.170 - Application started, Sub MyRules completed
[12/02/2009 16:52:35] 69.34.161.80 - Application started, Sub MyRules started
[12/02/2009 16:52:35] 69.34.161.80 - Application started, Sub MyRules started
[12/02/2009 16:52:35] 69.34.161.80 - Application started, Sub MyRules started
[12/02/2009 16:52:38] 69.34.161.80 - Application started, Sub MyRules completed
[12/02/2009 16:52:38] 69.34.161.80 - Application started, Sub MyRules started
[12/02/2009 16:52:39] 69.34.161.80 - Application started, Sub MyRules completed
[12/02/2009 16:52:39] 69.34.161.80 - Application started, Sub MyRules completed
[12/02/2009 16:52:40] 69.34.161.80 - Application started, Sub MyRules completed

【问题讨论】：

标签： asp.net global-asax web-applications

【解决方案1】：

检查事件日志，有些东西导致应用程序池回收。

【讨论】：

【解决方案2】：

检查应用在什么情况下会重启。最近我们正在将一些日志条目写入 bin 文件夹，并且发生了完全相同的事情，我们不明白原因。 然后终于意识到对bin文件夹进行任何修改都会导致应用重启。

【讨论】：

在过去的几个小时里，我一直在做这件事并与我的网络应用程序搏斗。感谢您在这里的回答，即使与这个问题有关的情况并不完全一样！
+1 - 我在那里转储了一个生成的 SQL 文件，但不知道为什么应用程序会重新启动。如果可以的话，我会再投票 1000 次。
感谢您节省了长途旅行！

【解决方案3】：

原来是个泄露的dll……

【讨论】：

经过 5 年，它现在发生了重大泄漏......但说真的，如果我没记错的话，那是一个第 3 方重写 dll，其中有一个错误，并且引发了导致应用程序回收的错误连续……记不住细节
有问题的第三方 dll 就是！ =)
我对你投了反对票，因为这是一个模糊无用的答案，对任何人都没有帮助。
是的，我阅读了第二条评论。仍然是一个无用的愚蠢答案，对任何人都没有帮助。
你问了一个问题。很抱歉，答案不是您想要的。

【解决方案4】：

我在多次调用 Application_Start 时遇到问题，事实证明这是因为我设置了多个实例。愚蠢的错误，但我想指出它。

【讨论】：

【解决方案5】：

我不知道为什么，但我在日志中看到了同样的事情。可能是因为它花费的时间太长并且您同时有多个请求？无论如何，为了安全起见，我添加了这段代码：

public class MvcApplication : HttpApplication
{
    private static volatile bool hasRegisteredBgTasks = false;
    private static object registeredBgTasksLock = new object();

    protected void Application_Start()
    {
        lock (registeredBgTasksLock)
        {
            if (hasRegisteredBgTasks)
            {
                return;
            }
            // Actual start up code.
            hasRegisteredBgTasks = true;
        }
    }

    // Other Application methods...
}

【讨论】：

在我的情况下，另一种可能性是使用 web 部署到实时站点。我可能已经部署了一半，用户点击它，启动应用程序，然后更多文件进入并再次重新启动。