I am creating a search results page in C# in an ASP.NET 1.1 page. In my data layer I have a DataSet that stores the result of a plain old ADO.NET stored procedure call. The DataSet has two DataTables and I'm using a DataVIew to filter and sort the columns.
I only want to fill the dataset once, and then work on the DataTables and derived DataView until the page is unloaded. How best should I cache the DataSet in my DAL so that it is filled only PageLoad? Do i put it in a Cache object, a static member variable, a property...
Why does Application_AuthenticateRequest make so many round trips before actually loading a page. I've noticed that at times it will process the same logic 10 or more times before actually loading a single page?
I don't understand why this is happening, and it makes me worry about excessive & unnecessary performance loads.
I'm seeing an issue of some static pages that are using the browser cache, which is not desired. To prevent caching, I'm setting
<clientCache cacheControlMode="DisableCache" />
in the relevant <location> tag in web.config
If I open the page in Firebug (in the Net tab), I see that the Response headers have Cache-Control: no-cache which is correct, but the status of the Response is 304 Not Modified! Isn't that a contradiction? How can I get it to stop caching (i.e. always send a 200 with content)?
I havent used asp.net 2.0 rsskit..didnt know there wasone..
anyways.. I have this RSS code that pulls RSS contents from a stored proc into a dataset (ds)..
Question : How can I cache the Dataset variable (ie ds) so that if I have 100 hits in 5 min I dont get 100 pulls on the stored proc. [NOTE: I assume its best to cache the dataset]
my code for RSS from the dataset (note has a few custom function etc..)
I need to use caching in my project. The problem is that, When page is firstly load ı cached a dataset. Then after after I update or insert a new record in table. my dataset returns from the cached records.
I am writing a web page that returns a small volume of data from a database table. The database is polled every 1 second and the data will be the same for every user. As every user is accessing the same data, there is no need for each user to poll the database and use up db resource.
Therefore, I think I should be using application caching to store the data in a dataset. However, I am slightly stumped as to how to do this.... because how can i ensure that the dataset is kept up to date.
The only way I can think to do this is to have a master user/session (i.e. the first session in the application) that keeps the cache object updated every second, then other users can use that cache object. If the first session ends, then the next requestor of the cache will pick up responsibility for keeping the dataset up to date.
I'm storing a dataset in an ASP.Net WebApplication-Cache. Every user in this intranet-app uses the same instance. On insert/update/delete-actions the database will be updated and the dataset is modified accordingly.
But rarely I get an exception that indicates that I've missed something. I assume that it must have something to do with thread safety.
Collection was modified; enumeration operation might not execute
In lines where i access a DataTable in the Dataset, for example:
Dim view As New DataView(dsERP.ERP_Charge, filter, sort, _ Data.DataViewRowState.CurrentRows)
It was apparently changed by another thread while the view enumerates the datatable.
What is the best way to make this thread safe?
Edit: as you've mentioned i need to lock the objects on add/edit/delete operations. MSDN* says that a DataSet is thread-safe for multiple users. What does this mean, are the DataTables in the Dataset also thread-safe? And how to lock a single datatable on write-operations and not the whole dataset?
*ADO.NET - Multithreaded Programming ADO.NET is optimized for performance, throughput, and scalability. As a result, the ADO.NET objects do not lock resources and must only be used on a single thread. The one exception is the DataSet, which is thread-safe for multiple readers. However, you need lock the DataSet during writes.
This is the property that returns the dataset:
Public ReadOnly Property dsERP() As ERPModel.dsERP Get If Cache("DS_ERP") Is Nothing Then Cache("DS_ERP") = New ERPModel.dsERP FillDataSet() End If Return DirectCast(Cache("DS_ERP"), ERPModel.dsERP) End Get End Property
i've modified the insert/update and delete operations in the following way(dsRma is a dataset):
Dim success As Boolean SyncLock dsRMA.RMA success = insert() End SyncLock
First, does it work now if another thread tries to enumerate the RMA-Table? Second, is it sufficient to lock the datarow that gets updated instead of locking the whole datatable(see below)?
Dim thisRMA As ERPModel.dsRMA.RMARow = dsRMA.RMA.FindByIdRMA(Me.IdRma) Dim success As Boolean SyncLock thisRMA success = update(thisRMA) End SyncLock
Is it better to have the calculated field returned with the rest of the results or is it better to calculate it later when you need it?
Example: I have a GridView that displays search results that has many fields like:
Application ID Name Account Type Account Number etc.
The account number field is not always consistently the same thing though. For accounts of type A they are eight digits long and for accounts of type B they are twelve.
After the search if they select a record and choose to continue the application I need to check the eigit digit account number for any access restrictions. All accounts of type A and B have an associated eigit digit account number, it is just that type B are the only ones to have the twelve digit number.
So should I add a redundant hidden field like "Common Account Number" to the search results and just hide it, thus making the heavily used search take slightly longer and making the results grid take up more space in the view state?
Or
Should I call the database when they try to continue the application and translate the Application ID into the eigit digit number so that I can use it to do my access restriction check? This will require one extra call to the database but the translation should be fast as both fields are in the same table and the application ID is a primary key. The continue application button will be used less as there are many other command options.
I've got my validation wired up through my Service layer, and my Birthdate property looks like this.
[Code]....
The client side validation works properly if I input something like `12/12/1990` but when the form is submitted, the server side validation trips and I'm told the entry is invalid. I'm using the jQuery-UI Datepicker to input the date, however when I disable the datepicker, the problem persists.Am I missing something here? I thought the client side and server side would be the same thing.If I remove
[Code]....
Then the form submits. It's obviously something to do with the Regex.
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?
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 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.
I'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?
I 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?
