If multiple users access a web-form at the same time, how can I allow that using my code? Essentially each user reads and writes one variable in the application, and concurrent access is causing problem there.
View 5 RepliesHow to avoid concurrent login for same user?
View 1 Repliesin one request i am updating session variable. in the other request, i am trying to access that session value, but it was blocked until the first request finish. I am using C# with ASP.NET 2.0 UPDATE: My page code looks like this.
while(int progress = DoWork() && progress <= 100 ){
Session["Progress"] = progress;
}
and my handler just return Session value.
context.Response.Write(Session["progress"].toString());
context.Response.End();
Suppose I have two threads(Thread1, Thread2) where the threads are accessing the cache for a given object such as in the code below nearly at the same time:
Dim expensiveToGetData = Cache("ExpensiveDataKey")
If ExpensiveToGetData is nothing then
'because the cache has expired
ExpensiveToGetData = LoadExpensiveDataFromDataSource()
Cache("ExpensiveDataKey") = ExpensiveToGetData
end If
ProcessExpensiveData(ExpensiveToGetData)
Isn't it possible for both threads to load the cache because they both requested data from the cache that was nothing/expired? I've run some tests on a local machine and it seems that the cache is being loaded more than once. Is this a normal pattern?
I am stuck with the issue of concurrent access to Session object. Actually my problem is i m writing to session in frame1 and trying to access that same Session object at the same time in Frame2's Page. I know about the reader/writer lock. I made the enablesessionstate = readonly in the page where i m writing to session. its giving me strange behavior on IE and firefox.
Its working concurrently in IE8 ( means page2 is diplaying modified values while page1 is changing the session object) but does not work in Firefox even page load is not called untill function on page 1 completed. Either anyone can fix my issue with firefox or there is new solution to reader/writer lock so that i can read the session at the same time while writing.
i'm developing a ASP.NET web application which uses the AjaxControlkit 3.0.30512.20315. I have a ToolkitScriptManager instance on my master page which has some ScriptReferences in the CombineScripts collection. If i access my default page from 2 differenct clients after an iisreset, i get the following exception
[NullReferenceException: Object Reference not set to an instance of an object.]
System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +143
System.Collections.Generic.Dictionary`2.set_Item(TKey key, TValue value) +11
AjaxControlToolkit.ToolkitScriptManager.GetScriptCombineAttributes(Assembly assembly) +129
AjaxControlToolkit.ToolkitScriptManager.IsScriptCombinable(ScriptEntry scriptEntry) +148
AjaxControlToolkit.ToolkitScriptManager.OnResolveScriptReference(ScriptReferenceEventArgs e) +415
System.Web.UI.ScriptManager.RegisterScripts() +191
System.Web.UI.ScriptManager.OnPagePreRenderComplete(Object sender, EventArgs e) +113
System.Web.UI.Page.OnPreRenderComplete(EventArgs e) +8698462
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1029
Using .NET Reflector i found out that the GetScriptCombineAttributesmethod access a static dictionary, which is not protected against concurrent access. Either i have a race condition in my code or there is a bug in the AjaxToolkit.
I have a strange problem in my ASP.Net 3.5 application. When multiple users try to access the same page (which has some long running methods), the application crashes at a point where it tries to open a connection to the database (a static method inside a static class). It appears that the connection is already open. However, this does not happen when there is only one user using the application. What I cannot understand is that how do actions of one user affect the other in a web application?
I double checked that all my open connections are being closed after performing their operation by appending a line of text to a text file whenever a connection is opened or closed. The number of opened and closed connections was equal. Also, the connections are opened and closed from one place only, where the close method is inside a Finally() block.
I currently store ASP.net application data in XML files. Now the problem is I have asynchronous operations, which means I ran into the problem of simultanous write access on a XML file... Now, I'm considering moving to an embedded database to solve the issue. I'm currently considering SQlite and embeddable Firebird. I'm not sure however if SQlite or Firebird can handle multiple concurrent write access. And I certainly don't want the same problem again. Anybody knows? SQlite certainly is better known, but which one is better - SQlite or Firebird ? I tend to say Firebird, but I don't really know. No MS-Access or MS-SQL-express recommodations please, I'm a sane person.
View 5 RepliesI'm developing web application with concurrent user using the application. The problem i'm facing is that if the first user login his details are taken affecting the second user how is process the data in the application.How to avoid it?the best way to code to maintain concurrent users.
View 4 RepliesI am involved in designing a asp.net webforms application using .NET 3.5. I have a requirement where we need to log exceptions.
What is the best approach for exception handling, given that there would be concurrent users for this application?
Is there a need or possibility to log in exceptions at a user level? My support team in-charge wants to have a feature where the support team can get user specific log files.
To give you a background, this application is currently on VB 6.0 and we are migrating it along with some enhancements. So, today the support personnel have a provision to get user specific log files.
In my ASP.NET MVC2 web app I have a page which goes off and gets results from a number of different web service feeds. These return times vary so I want to basically display them as they return after the page loads. I also want my user to be able to kick of requests that can run concurrently with these other requests.
At the minute my page just seems to queue up the requests. The web service calls returning one at a time in the order they are called and then the user can kick of requests.
Is this a case for the asyncController or is there an easier/better way of working this?
I am trying to create a system in which there will be a single user accessing his acount from two endpoints simultanously.
I think this is possible.
1) How to restrict the user to have only one session at a time?
2) How to change it to have limited number of sessions per user at a time?
My application is windows authenticated. The application pulls JUST the userName from the current windows account. Then I provide site access to this user depending on his account privileges. If his userName belongs to the admins list he is directed to admin screens. If his username belongs to users list he is directed to users screens. I handle this security in C# and some SQL tables(No membership provider and no Active directory security in the app).
I need to be able to prevent multiple concurrent logins for the same userName.
I have an ASP.NET MVC application that use the default ASP.NET Membership Provider. My customer asked to implement a feature that prevent users to log in (for example for users that resign and leave the company). I cannot use the IsApproved flag of the Membership table because that field is used to confirm user egistration. Is there any built in functionality for doing this? What are your experiences in scenarios like this?
View 1 RepliesI need to log every user-action taken on a database using the username of the person logged into my ASP.net application as the identifier in the log. What is the easiest way to do this? I guess that for every method call to my data access layer I need to log the parameters of that call and the username and then call a new "log event" method that writes the details of the call to a table. Am I on the right track?
View 2 RepliesI have a .net web application (framework 2.o) and SQL Server 2005 as my backend. I need to design an application which fetches a particular unique pin number to a customer and then mark this record as used. The problem I face is as the no of concurrent users are more , same pin number is getting allotted to multiple users.
View 3 RepliesWe have an ASP.NET 3.5 Web application in which we have faced the below issue:
The application is working fine but suddently at one point application URL prompts for the authentication. When we (the support team) checked the server, we were able to identify that the access was denied for some of the main files (like web.config, default page). When we enabled the access the application started working fine.
concerning requests being blocked from a main window after a popup window had initiated a file download. Further requests from the same session are being queued until the download is complete. So, is there any way to override this? Is there anyway to tell asp.net to not serialize same session requests? Is there any way to tell asp.net to ignore session for a specific request...httphander(module) or otherwise?
why requests from the same session are being queued until the download is complete. please tell me the funda behind it and how to overcome it.
I have a requirement for building an instant messenger application for the selected user.
I have googled for the solution but without any sucess.My requirement is once a user initiates a chat with another user,the another user needs to get a popup of the chat window,where the two users can start chatting.
How to control concurrent requests for web sites?
View 1 RepliesI did a winforms applicaion using C#. I has 'n' number of forms.I like to track application usage time from user login to application exit.
View 1 Repliesi am new to asp.net programming i am trying to connect asp.net web application with ms access 2007 database. i have taken with two text boxes and when i enter some data in it and press submit button the data must load in access db i created with same fields.
my code is :
[code]....
Syntax error in string in query expression what is the correct way of inserting data into access db and what is the Syntax error in string in query expression.
I am trying to render an SSRS report via a link in my Web Application. If I use the following code, the report generates as expected:
[Code]....
When that code runs for a certain set of parameters, the following type of string is generated:
[Code]....
The issue is with the url string that is generated, which looks like this:
http://SomeServerPath/Test_rptAuditReport&__VIEWSTATE=%2fwEPDwULLTE2MTY2ODcyMjlkZKWE5%2ftLm5SJFKayb2vmmYGsf7Qc&__SCROLLPOSITIONX=0&__SCROLLPOSITIONY=0&__EVENTTARGET=&__EVENTARGUMENT=&rs%3aCommand=Render&AuditHeaderSK=94&SubmissionSK=122&UserSK=169&SegmentSK=2&AuditformSK=208
Notice that it has inserted some unwanted items into the url string:
&__VIEWSTATE=%2fwEPDwULLTE2MTY2ODcyMjlkZKWE5%2ftLm5SJFKayb2vmmYGsf7Qc&__SCROLLPOSITIONX=0&__SCROLLPOSITIONY=0&__EVENTTARGET=&__EVENTARGUMENT=&
It also does not seem to correctly interperet the "rs:Command", interpreting the ":" as "%3a". If I manually strip that out of the url and fix the %3a to a colon, then the report renders. I understand some of those events are "hidden fields" on a postback and that's why (I guess) they're being included in the url string, but I can't seem to find anyway to suppress them, or to get the colon interpreted correctly in the rs:Command. I've tried to remove the Viewstate with the Page Directive EnableViewState=False, but that doesn't stop the Viewstate from appearing in the string.
I have an acess db which has primal key ID - Customer, and personal data of the customer .
In another db OR the same, to have the username and login of the customers.
I want to make a login form so if u/n & pass of a customer is correct, to have access to modify (insert, delete, update) his data of the db - his ID's only.
I have my asp.net application with ms sql 2005 express.. in my localhost...
Now i have requirment with my boss i need to show this webpage to access all over the world...
i have bought asp.net webspace with hosting provider without database...
he has given me the some ip XXX.XXX.XXX.XXX where im going to log on my cpanel...
so i would like to know how to access my database with my asp.net application which is in hosting company....
i would like to know step by step configuration... to ms sql 2005 database...