插入后立即删除ASP.NET HttpContext缓存 [英] ASP.NET HttpContext Cache removes right after insertion
问题描述
我有一个ASP.NET 4 Web服务.
它在ModuleController
控制器中具有ImportModule
动作.
I have an ASP.NET 4 web-service.
It has an ImportModule
action in a ModuleController
controller.
这就是它的工作方式:
- 用户将模块上传为CSV文件.
- 正在使用
HttpPostedFileBase.InputStream
和自定义CSV读取类读取此文件. - 根据一些规则和验证,此文件正在转换为C#对象.如果文件有效,则它将转换为C#对象,并以唯一的GUID名称存储在Cache中,并且将用户重定向到
CompleteImportModule
操作. - 用户检查数据是否正确,并确认上传.
- The user uploads a module as a CSV-file.
- This file is being read using
HttpPostedFileBase.InputStream
and custom CSV-reading class. - This file is being transformed to a C# object according to some rules and validations. If a file is valid, then it transforms to C# object, stores in a Cache with unique GUID name and a user is redirected to
CompleteImportModule
action. - User checks if data is correct and he confirms uploading.
长话短说,有一个代码可以告诉您更多信息:
ImportModule
操作.
Long story short, there is a code which tells you more:
ImportModule
action.
public ActionResult ImportModule(HttpPostedFileBase file)
{
if (!ModelState.IsValid)
{
return RedirectToAction("Index");
}
ModuleQuestion[] questions;
ModuleInfo moduleInfo;
string uploadId = Guid.NewGuid().ToString();
// It is my custom CSV-reader and it works. Values are assigned
FormDataCsvReader csvReader = new FormDataCsvReader(file.InputStream);
if (!csvReader.Process(out questions, out moduleInfo))
{
// File is invalid
return RedirectToAction("Index");
}
ViewBag.UploadId = uploadId;
ViewBag.ModuleInfo = moduleInfo;
ViewBag.Questions = questions;
HttpContext.Cache.Add("UploadModule_" + uploadId,
new Tuple<ModuleInfo, ModuleQuestion[]>(moduleInfo, questions),
null,
Cache.NoAbsoluteExpiration,
TimeSpan.FromMinutes(30),
CacheItemPriority.NotRemovable,
(k, v, r) =>
{
LoggingFactory.GetLogger().Debug("Removed from cache: {0}. Reason: {1}", k, r);
});
return View();
}
在视图ImportModule
中:
// Output data from ViewBag.ModuleInfo and ViewBag.Questions
<form method="POST" action="@Url.Action("CompleteImportModule")">
<input type="hidden" name="uploadId" value="@ViewBag.UploadId"/>
<input type="submit" value="Send">
</form>
CompleteImportModule
操作:
[HttpPost]
public ActionResult CompleteImportModule(string uploadId)
{
var item = HttpContext.Cache["UploadModule_" + uploadId];
if (item == null) RedirectToAction("Index");
// upload module
HttpContext.Cache.Remove("UploadModule_" + uploadId);
return RedirectToAction("Index");
}
但是,我遇到了一些问题.我无法上传模块,因为在插入后立即从缓存中删除了该值.它仅存储一秒钟:
However, I met some problems. I cannot upload the module because the value is removed from a Cache right after being inserted. It is stored only for a second:
DEBUG 2015-06-22 15:00:18,696 thread 85: Added to cache:
UploadModule_c843077d-21d0-4e9f-9e5e-3df82da4bac8
DEBUG 2015-06-22 15:00:19,935 thread 48: Removed from cache:
UploadModule_c843077d-21d0-4e9f-9e5e-3df82da4bac8. Reason: Removed
reason
是已删除",这意味着它没有过期,并且由于优化,IIS尚未将其删除,但看来我删除的是我本人.
我很确定我什至没有在CompleteImportModule
之前访问此缓存记录.
The reason
is "Removed" meaning that it is not expired and IIS hasn't removed it due to optimization but it looks like I removed is myself.
I am pretty sure that I am even not accessing this cache record before CompleteImportModule
.
我尝试将new StackTrace().ToString()
放在CacheItemRemovedCallback
中.就是这样,如果它可以以某种方式提供帮助:
I have tried putting new StackTrace().ToString()
in a CacheItemRemovedCallback
. That's it, if it can help somehow:
at CPMAdministrator.Controllers.ModulesReferenceController.<ImportModule>b__9(String key, Object value, CacheItemRemovedReason reason)
at System.Web.Caching.CacheEntry.CallCacheItemRemovedCallback(CacheItemRemovedCallback callback, CacheItemRemovedReason reason)
at System.Web.Caching.CacheEntry.Close(CacheItemRemovedReason reason)
at System.Web.Caching.CacheSingle.UpdateCache(CacheKey cacheKey, CacheEntry newEntry, Boolean replace, CacheItemRemovedReason removedReason, Object& valueOld)
at System.Web.Caching.CacheSingle.Dispose(Boolean disposing)
at System.Web.Caching.CacheMultiple.Dispose(Boolean disposing)
at System.Web.HttpRuntime.Dispose()
at System.Web.HttpRuntime.ReleaseResourcesAndUnloadAppDomain(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
为什么会这样?是IIS池回收吗?如何确保未删除文件?或者我该如何有效地以其他方式存储这些数据?
Why is it happening? Is it sort of IIS pool recycling? How can I ensure that the file is not being removed? Or how can I effictively store this data another way?
推荐答案
我花了几个小时找到答案,并在发布问题后立即找到答案!让我与您分享我的经验.
I have spent several hours finding an answer and found it right after posting a question! Let me share my experience with you.
根据我的StackTrace,我了解到缓存已清除,因为该应用程序已结束并被处置:
According to my StackTrace, I understood that the cache has been cleared because the application has been ended and disposed:
at System.Web.HttpRuntime.Dispose()
at System.Web.HttpRuntime.ReleaseResourcesAndUnloadAppDomain(Object state)
我所需要的只是找到原因.
All I needed is to find a reason of it.
我已经打开Global.asax
文件并添加了Application_End
方法.
I have opened my Global.asax
file and added a Application_End
method.
public class MvcApplication : HttpApplication
{
protected void Application_End()
{
}
}
它已在视图渲染成功之后以及清除缓存之前立即触发.成功!现在,我需要知道应用程序终止的原因.
It has been triggered right after view rendering success and right before cache clearing. Success! Now I needed to know the reason of application ending.
这篇文章帮助我:
有
System.Web.Hosting.HostingEnvironment.ShutdownReason
指示为什么终止应用程序的属性.它的 值可以从Application_End()
内部检索.
There's
System.Web.Hosting.HostingEnvironment.ShutdownReason
property that indicates why the application is being terminated. Its value can be retrieved from insideApplication_End()
.
我在Application_End
的开头添加了一个断点,并添加了System.Web.Hosting.HostingEnvironment.ShutdownReason
进行观看.
I added a breakpoint in a beginning of Application_End
and added System.Web.Hosting.HostingEnvironment.ShutdownReason
to watch.
这就是它存储的内容:BinDirChangeOrDirectoryRename
.
That's what it stored: BinDirChangeOrDirectoryRename
.
此后,我了解到原因是我的log4net
在BinDirectory
中写了日志.我只是不知道,如果bin
目录已更改,则IIS正在完成Web应用程序.
After that, I have understood that the reason is that my log4net
is writing logs right in BinDirectory
. I just never knew that IIS is finishing web applications if bin
directory has been changed.
我已将日志移至父文件夹(应用程序本身),现在可以使用了.
看来我需要阅读有关ASP.NET的更多信息.
我希望它能对某人有所帮助.感谢所有尝试提供帮助的人.
I have moved my logs to a parent (application itself) folder and now it works.
It looks like I need to read more about ASP.NET.
I hope that it will help someone. Thanks to everybody who tried to help.
这篇关于插入后立即删除ASP.NET HttpContext缓存的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!