I have to develop the Key dependecy cache techniques. I have tried this. i got the error. I have shown the details below.
HttpContext.Current.Cache.Insert(
Dim MyDependency
As
New CacheDependency(Nothing, keys)"SqlPubsEmployees",
ds, MyDependency)
since asp.net contains multiple threads that are executing at the same time.so if 2 threads access an object (simple or complex) that i got from the the asp.net httpcontext Cache.can't this lead to state problems on that object if these 2 theads tried to modify/read it at the same time?so what kind of precautions should i implement?for example i am thinking maybe locking the object while working with it? (wont this cause performance problems?)or maybe when i retrieve some object from the cache i should create a copy from it?
or maybe i dont need to worry about this issue at all?
Scenario: I have a complex Asp.net app serving various units through programmatically constructed control collections in HttpModules. Some of these controls use Asp.NET Ajax.
Across many different units, ScriptResource.axd averages a transfer size of ~27k.
I have a ceiling that only allows ~3k for it.
There definitely isn't time to retrofit all the Ajax functionality with jQuery or hand-rolled js functions or whatnot. We already have the .axd coming over with gzip encoding (uncompressed it's more like 97k). It's often cached, but that doesn't matter: I have to hit a hard, low, externally-imposed limit on first-request total transfer size... markup, scripts, images & all summed up a-la firebug. I've been avoiding the .axds, but there really isn't anywhere else to shave bytes, and I have 24k to go.
Possible approaches: I'm not yet using Asp.NET 3.5 SP1's compositescript functionality, but I figure that would only save on request/response headers, and I'm not even sure headers count against me.
I don't have any other ideas other than something radical, like creating a response filter that uses reflection & some dictionaries to figure out what js functions are actually needed, and only emit those. I could cache the resulting list for each unit, since I have a low response time ceiling as well, and I don't think the .axds change from one request to another. Is this feasible? Any other ideas? ...what if I buy beer for the hero with a solution?
I am new to WCF. Please tell me what are different WCF Service Hosting techniques..
View 1 Replieswhat MVC stands for,but if I'm already developing .NET websites without it,is there any reason I would need/want to use it?is it designed for people who already have experience with developing in an MVC environment and wanted a ".net"version of it?Is there some "head-to-head" comparison of MVC against other programming environments or techniques that have been written? It seems like what I might gain in development speed I might lose in flexibility.maybe I just don't understand what all the fuss is about.hence this post!
View 6 RepliesI am trying to load test a web application, but I am having a hard time finding good tools that are affordable. I cam across Web Performance Load Testing Tool which is pretty cool, but limits you to 10 users and after that it costs thousands. any good techniques for load testing a web application?
View 5 RepliesRecently I was asked the following question at interview."What are the different way to bind a Data Control in ASP.Net".
I have answered
Typed DataSet
Collections
Stored Procedure.
The interviewer expecting a lot more. Can anyone explain me the different way that we can bind the data controls?
I am in the process of building a survey using asp.net and store these results into a database. Now this is what I am trying to achieve: - The survey is fairly long but will be split up in sections. - the way I have been told to develop this is to save each section into the database when the user clicks on a next button for example rather than clicking a final submit button and then submitting the results all in one go to the database. The reason being is for example, the user's browser crashes etc or if they accidentally close it down. I need to build it such a way that survey can remember who the person is.
I can't use windows authentication as it will be externally based, is there anyway I can uniquely identify people when they arrive on the web application e.g. by using a guid? Can it be guaranteed that the person who arrives on the application with a guid on that machine be exactly the same when he/she arrives again?
Has anyone been able to cache .aspx pages using the HTML cache manifest? I am porting an html application over to asp.net (and mvc2) and I get a 404 error when trying to cache any *.aspx page. Other files still cache normally (.js, .css, etc). I have changed permissions, handlers, and file names and still no luck. Below is the actual manifest:
CACHE MANIFEST
# This file was generated at 2/28/2011 4:03 PM
CACHE:
/Content/Site.css
/Content/Table_style.css
/Scripts/jquery-1.5.min.js
/Scripts/json.js
/Scripts/persist-all.js
/Views/Data/Details.aspx
/Views/Data/NotFound.aspx
/Views/Data/OffLine.aspx
/Views/Data/OnLine.aspx
/Views/Data/Test.aspx
/Views/Home/About.aspx
/Views/Home/Index.aspx
/Views/Shared/Error.aspx
Is it correct to implement my caching object like this in my controller :
[code]....
And I Use it like this :
[code]....
I'm working on an ASP.NET application that accesses Team Foundation Server 2010 and creates new work items. The application is running in the DefaultAppPool, using NetworkService as the identity. I'm getting the error below:
[UnauthorizedAccessException: Access to the path 'Cachev10' is denied.]
[code]....
We were able to work around the issue by turning the Cache folder into a network share and giving NetworkService full access to the share. I'd prefer not to have to do this, but it seems to be working correctly now.
We have a wfc layer that wraps the business classes and database access and use a client that lives on the database layer. Amongst our group we are attempting to form standards. Some want to have the client call the web method and pass the page they are requesting and the page size. Pass that to the database and then page in SQL Server use RowNum.Some want to cache the full list of objects in http cache on the service tier and page in memory. They concern here is memory use on the server.
Which would be best for a medium number of users with potentially large number of records to manage (say 30K) Is it better to cache them all in memory and work from there or page at the database as the application scales?
What are the "optimal" parameters for creating an AppFabric cache when you will be storing session state in the cache? MSDN Cache-Related Commands
Powershell command line:
New-Cache [-CacheName] <String> [-Eviction <String>] [-Expirable <String>] [-Force [<SwitchParameter>]] [-NotificationsEnabled <String>] [-Secondaries <Int32>] [-TimeToLive <Int64>]
[code]...
Since I don't want my sessions to be removed unless the session has been abandoned either via code or Session Timeout...For eviction, I would think "None" and for expireable, I would think False.I have tested and calling Session.Abandon does remove the object from the cache. I have also tested to see if by extending my session, the session object in cache is also extended. This does seem to work the "correct" way.
We have a data driven ASP.NET website which has been written using the standard pattern for data caching (adapted here from MSDN):
public DataTable GetData()
{
string key = "DataTable";
object item = Cache[key] as DataTable;
[code]...
The trouble with this is that the call to GetDataFromSQL() is expensive and the use of the site is fairly high. So every five minutes, when the cache drops, the site becomes very 'sticky' while a lot of requests are waiting for the new data to be retrieved.
What we really want to happen is for the old data to remain current while new data is periodically reloaded in the background. (The fact that someone might therefore see data that is six minutes old isn't a big issue - the data isn't that time sensitive). This is something that I can write myself, but it would be useful to know if any alternative caching engines (I know names like Velocity, memcache) support this kind of scenario. Or am I missing some obvious trick with the standard ASP.NET data cache?
We are using HttpRuntime.Cache API in an ASP.NET to cache data retrieved from a database.
For this particular application, our database queries feature a LOT of parameters, so our cache keys look something like this:
table=table1;param1=somevalue1;param2=somevalue2;param3=somevalue3;param4=somevalue4;param5=somevalue5;param6=somevalue6... etc...
we have so many parameters that the cache key is several hundred characters long. is there a limit to the length of these cache keys? Internally, it is using a dictionary, so theoretically the lookup time should be constant. However, I wonder if we have potential to run into some performance/memory problem.
I have use Nhibernate in my MVC Project by me known, Nhibernate have cache on Session and Object. now, I want use HttpContext.Current.Cache (system.web) for cache data something in project. my code same that have problem, haven't it. and that's right or wrong.
View 2 RepliesI've got a web application that runs of a state server. It looks like soon it may need to distributed and there will be two web servers behind a load balancer.
This works great for session state but my next challenge is Cache
My application leverages heavily of cache. I understand ASP.Net 4.0 will be offering more here but nothing much has been said about the how too.
There are two challenges that I face
1). Each webserver will have its own copy of cache whereas it would be more efficient to put this to a third server the same as session state is put to state server.
2). The real challenge is keeping cache in sync if a simple dataset derived from the database is changed my code dumps that cache item and reloads the cache. That's all well on one webserver but webserver number two wont know to drop that particular cache item and reload it. This could cause some unexpected problems in the application.
For scenario number 2 I could attempt to do some smart coding so server number two knows to dump the cache and reload it.
My guess is someone else has already been here before and there's probably a better implementation approach rather than writing extra code.
Does anyone know how I could achieve the goal of keeping Cache in sync between multiple webservers or even better farm Cache management to another server?
I need to enable caching in my asp.net application, but I do not want to use the webserver's memory for holding cache objects. If I add the page directive for output caching will the page be stored in the asp.net cache object?
View 2 RepliesI want to be able to maintain certain objects between application restarts.
To do that, I want to write specific cached items out to disk in Global.asax Application_End() function and re-load them back on Application_Start().
I currently have a cache helper class, which uses the following method to return the cached value:
return HttpContext.Current.Cache[key];
Problem: during Application_End(), HttpContext.Current is null since there is no web request (it's an automated cleanup procedure) - therefore, I cannot access .Cache[] to retrieve any of the items to save to disk.
Question: how can I access the cache items during Application_End()?
Im building a image gallery which reads file from disk, create thumbnails on the fly and present them to the user. This works good, except the processing takes a bit time.
I then decided to cache the processed images using the ASP .NET Application Cache. When a image is processed I add the byte[] stream to the cache. As far as I know this is beeing saved into the system memory. And this is working perfect, the loading of the page is much faster.
My question is if there are thousands of images which gets cached in the Application Cache, will that affect the server performance in any way?
You know I have the way to Cache the data I've got from the SQL Server over data caching. In addition I can output cache web user controls.Whats about a web user control contains data from a SQL database? Does it make sense to cache the data and also cache the control?What is the best solution for the combination of these two components?
View 1 RepliesThis is one of the strangest errors I've ever seen.
I'm doing a very simple call to return values from the HttpRuntime cache. The call is:
return HttpContext.Current.Cache[cacheKey];
If it returns null, that's fine. I check if the returned value is null and act accordingly. I've been using this call for a long time.
Recently, for some reason, when cacheKey is set to this exact value:
"Topic_GridSelectAll:5,null,2010-08-31-20-00-00,Published,desc,5,1"
a System.OverflowException is thrown: Negating the minimum value of a twos complement number is invalid.
Nothing about the call, associated code or server has changed. If the cacheKey has slightly different characters, it works perfectly fine. For instance, this cacheKey returns null without throwing any exception:
"Topic_GridSelectAll:5,null,2010-08-31-21-00-00,Published,desc,5,1"
Notice, the only difference between those two strings is the time characters: 2010-08-31-20-00-00 versus 2010-08-31-21-00-00.
Why the hell would that make any difference? And why now after all this time?
The stack trace is:
[OverflowException: Negating the minimum value of a twos complement number is invalid.]
System.Math.AbsHelper(Int32 value) +12753486
System.Web.Caching.CacheMultiple.UpdateCache(CacheKey cacheKey, CacheEntry newEntry, Boolean replace, CacheItemRemovedReason removedReason, Object& valueOld) +142
System.Web.Caching.CacheInternal.DoGet(Boolean isPublic, String key, CacheGetOptions getOptions) +122
MyProject.Helpers.CacheHelper.GetData(String cacheDomain, String cacheKey) in ...
I've tried changing the cache call to use HttpRuntime.Cache instead (ie. HttpRuntime.Cache[cacheKey]), but that made no difference. I know it's the same underlying cache provider, but I thought maybe the different call would make a difference.
I have a server control that I developed which generates navigation based on a third party CMS API. Currently I am caching this control using the PartialCaching attribute. The CMS uses cache key dependencies to invalidate the cache when a user makes an edit, however in the case of my server control it does not get invalidated and the updated navigation will not show up until the cache expiration set by the PartialCaching attribute.Here is my two part question:
What is the proper way to programmatically cache a server control, without using the PartialCaching attribute, and adding a cache key dependency?
Is it possible to continue to use the PartialCaching attribute and add a cache key dependency?
i want to save a IQueryable in cache like this:
[Code]....
However when i try to retreive it and use it i get this error: The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.
I'm using the OutputCache for my pages, and I have a dynamic user control (login/register) . When the user try to sign in, the the control do not change the aspect because I´m using OutputCache. How can I exclude the "login/register" control from the cache?
View 6 Replies