Is it acceptable to cache an instance of the database connection on application start?
Looking at the MSDN documentation on thread safety, I quote:
Any public static [...] members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Given that, is it acceptable/safe for code such as this example below:
[code]...
In our ASP.NET application we perform some initializations upon the Application Start event.When the application is started in visual Studio 2010 with 'Debug->Start new instance' the ASP.NET Development server does not start new, and my Application's Start event is not fired.My workaround is to manually stop the development server - is there a setting to force this automatically?
View 1 Repliesi 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.
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?
I want to start a new thread to query a database while my web application continues running. I was under the impression that by using threads I can run the querying process independently while the normal web application page cycle carries on, but I could be wrong.
public class DbAsyncQuery
{
Dictionary<string, object> serviceResults = new Dictionary<string, object>();
public void UpdateBillingDB()
{
QueryAllServices();
foreach (KeyValuePair<string, object> p in serviceResults)
{
IEnumerable results = (IEnumerable)p.Value;
IEnumerable<object> sessions = results.Cast<object>();
DbUtil.MakeBillingDBEntry(sessions, p.Key);
}
}
public static string[] servicesToQuery = new string[] // Must go in config file ultimately
{
"xxx.x.xxx.xx"
};
public delegate void Worker();
private Thread worker;
public void InitializeThread(Worker wrk)
{
worker = new Thread(new ThreadStart(wrk));
worker.Start();
}
public void InitializeQuery()
{
Worker worker = QueryAllServices;
InitializeThread(worker);
}
private void QueryAllServices()
{
Dictionary<string, DateTime> lastEntries = DbUtil.GetLastEntries();
foreach (string ip in servicesToQuery)
{
string fullServicePath =
"http://" + ip + ":800/MyWebService.asmx";
//object[] lastEntry = new object[] { lastEntries[ip] };
object[] lastEntry = new object[] { new DateTime(2011, 1, 1, 0, 0, 0) };
object obj = WebServiceHandler.CallWebService
(fullServicePath, "MyWebService", "GetBillingDBEntries", lastEntry);
serviceResults.Add(ip, obj);
}
}
}
It seems to basically stall and wait to finish the query before loading the page (which can be thousands of rows, so it takes awhile). I put this in the following section of Global.asax:
protected void Application_Start(object sender, EventArgs e)
{
DbAsyncQuery query = new DbAsyncQuery();
query.UpdateBillingDB();
}
This is one of my first web pages, and I'm new to threading. I understand there is a difference between creating your own thread and using the ThreadPool. In this method, I am using my own thread, I think. Not sure if that's the best way. The querying process can be completely independent, and its only going to occur on scheduled intervals (every 8 hours or so). The user doesn't need to have up to the minute data, so it can take awhile. I just don't want the site to wait for it to finish, if that's possible.
I am trying to register the route collection in .net based on each session. The code I have works fine, you goto website/username and it loads the correct sub pages, but you have to restart the application to goto website/username2 to load those sub pages. But when the application is restarted the second one works, but then not the first one. Is there some way to create a different route collection per session not per application using system.web.routing.
View 3 RepliesI finished an intranet application using webconfig to store my connection string to an Access database which has linked tables to SQL Server 2005.
Everything works perfectly, but when I publish the application on a IIS server service, it seems like all connections fail... :(
I looked up on internet but found nothing on this. I think my webconfig file is correct :
[Code]....
I would like to start a System.Threading.Timer in my application when it launches (maybe deploy is the correct word). I have seen that you can use Application_Start() but this is only fired once the first request comes to the application. I need the timer to start as soon as the application is running so that it can check for work to process even if a user is not interacting with the site. How can I get the application to start the timer once it is up and running?
View 4 RepliesI am trying to run the 15 minutes movies MVC application but I got the following error:
Object reference not set to an instance of an object.
Description:
An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
[Code]....
I have a web service that calls another web service (not my design).The wrapper web service is our code the underlying web service is 3rd party.The issue is that when one of our apps calls the web service wrapper.. it opens a new connection to the underlying web service and that login time is around 10seconds! (3rd party issue)... the calls after the login are fast in testing.SO we are trying to have ONE login for all the calls to the underlying services. However our wrapper service is called one by one..I was thinking if there was a way to store the underlying web service connection in a cache (netbean?) I could reuse it for all web service connections to the 3rd party...
View 1 RepliesI just installed sql server 2008 R2 on my computer. I am trying to connect to sql server throught my C# code and everytime I run the C# program,
I get this error "A network-related or instance-specific error occurred while establishing a connection to SQL Server.
The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) "
The connection string that I used in my web.config file is
[Code]....
I am not sure what am I doing wrong, but I followed this article below step by step and still I am getting the same error
http://blog.sqlauthority.com/2009/05/21/sql-server-fix-error-provider-named-pipes-provider-error-40-could-not-open-a-connection-to-sql-server-microsoft-sql-server-error/
My instance name is MSSQLSERVER and the server that I am using is on my local machine and it has my computer name in it.
What is the right approach when users (authenticated domain admins) should be able to start batch jobs (usually exe files) from an IIS (7.x) aspx (c#) page? This is an intranet site. The batch jobs have to run on the web server as Domain Admins. The website pool is executed by network service or some similar restricted account in AD.
Approaches I can think of (and their disadvantages):
1. Start exe file with System.Diagnostics.Process.Start with another account. This feature is disabled in IIS 7.x, how do I allow it?
2. Create a sheduled task and call scheduled task-api. This unmanaged dll is giving VS compiler warnings because it's unsafe to call from managed code.
3. I suppose there's a better approach, because the previous suggestions doesn't appear safe or robust.
I have 3 Databases that I am pulling data from for my web site. 2 of the databases are in the same SQL instance, however the 3rd one is in a different SQL instance. Both of the SQL instances are installed on the same server, one of them is a Named instance and the other is installed under the default instance. So my connection strings look something like this:
<add name="ABCConnectionString" connectionString="Data Source=BobDataDB;Initial Catalog=Bob;User ID=*******;Password=*********;" ProviderName="System.Data.SqlClient"/>
<add name="BCDConnectionString" connectionString="Data Source=BobDataDB;Initial Catalog=Sue;User ID=*******;Password=*********;" ProviderName="System.Data.SqlClient"/>
<add name="EFGConnectionString" connectionString="Data Source=Bob;Initial Catalog=Sue;User ID=*******;Password=*********;" ProviderName="System.Data.SqlClient"/>
I'm in the process of moving this application from the Development Server to the Production Server when I noticed this issue. Previously the ABC and BCD connectionStrings where pointing to a different server and instance. So my question is how do I get this wo work with the server names being the same but the instances being different?
on desktop start has disappeared, getting above issue on double clicking/running any application.have VS2005 installed with sp1 and all other relevant updates as per MS..., i read some forums which states because of VC++ the system files may be currupted....have not installed VC++can anyone guide me the issue here and its solution...
View 3 RepliesI know that ASP.NET MVC has error filter attribute to handle specified error type. However, this feature cannot catch any error that occurs when application start. Therefore, I need to add some code to "Application_Error" method for handling this error like the following code.
public void Application_Error(object sender, EventArgs e)
{// At this point we have information about the error
var ctx = HttpContext.Current;
var exception = ctx.Server.GetLastError();
[code]...
i m running asp.net example code in my vs 2005. I am using following datasource. I have no sql express edition, but i have developer edition of sql server 2005.
[code]...
i have .mdf file and i got following error message.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I have this view:
@model MatchGaming.Models.ProfileQuery
@{
ViewBag.Title = "Index";
[code]...
I am using VS2008 and oracle 10g ODP.Net. The oracle database that I used in the connection is working and tested it using sql plus.The connection string when used in a GriDView works perfectly. Now when I created a new listview control with the same connection it gives an error.Database schema could not be retrieved for this connection. Please make sure connection settings are correct and the database is online
Object reference not set to an instance of an object at VSDataObjectSupport (478,6)
I have an appliaction that works fine and connect to the database.but when view the event log I can see that every minute I get this:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Shared Memory Provider, error: 40 - Could not open a connection to SQL Server)
On web.config yo can find:
[Code]....
I am using sql server fulll edition.any idea how should I solve this issue, I search on net but not found any helpful answer.
View 4 RepliesWhen I load the asp.net config tool in vs2010 it loads the page up fine but as soon as I click on security I get the following error:-
Code:
There is a problem with your selected data store. This can be caused by an invalid server name or credentials, or by insufficient permission. It can also be caused by the role manager feature not being enabled. Click the button below to be redirected to a page where you can choose a new data store.
The following message may diagnose the problem: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. I have tried a blank project with a login control on but get the same.
I have a class instance which is created by using Activator.CreateInstance() method. That class instance contains helper methods which are frequently used throughout the application. In order to avoid creating the instance multiple times, I'm just thinking about implementing an appropriate caching mechanism. The following consideration should be taken into account:
1) I can't use static class and methods.
2) There are around 6 instances (1 instance per class) per App Domain.
just wanna ask what is acceptable size of ViewState per page? What is the level I should start worried. Is there any objective measurement for viewstate size?
View 6 RepliesI am using Asp.Net MVC 2.0 for creating a user and assigning properties to the user at the same time. I am using my Windows account to access database on my local computer. I am using pre-installed MVC code o create a user with unique user name and password. User is created OK. Then I want to add profile properties like First and Last name at the same time.
I am creatingProfileBase object:
ProfileBase profileBase = ProfileBase.Create(profileInformation.UserName);
where profileInformation is a RegisterModel and has user info.
When I am trying to:
profileBase.SetPropertyValue(.....);
I am getting the following error # 2147467259 A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Shared Memory Provider, error: 40 - Could not open a connection to SQL Server)"}
Why is my connection string works fine the first time and not working now? And how to configure connection to use TCP-IP?
I have SQL Server Browser running ander Local account and openned port in my Firewall.
I am logged in as the administrator when I installed an application named pdflatex.exe on my server. This application works as a converter from LaTeX input file to Pdf file. I host an Asp.net MVC 3 application running under an Application Pool Identity with Load User Profile = True. The Asp.net MVC 3 code contains a code that executes pdflatex.exe using System.Diagnostic.Process instance as follows:
Process p = new Process();
p.EnableRaisingEvents = true;
p.Exited += new EventHandler(p_Exited);
p.StartInfo.Arguments = "-interaction=nonstopmode " + inputpath;
p.StartInfo.WorkingDirectory = @"c:mydomain.comworking";
p.StartInfo.UseShellExecute = false;
p.StartInfo.FileName = "pdflatex.exe";
p.Start();
p.WaitForExit();
From the scenario above, the web application runs under a restricted acount but it executes an external application under a default account that I don't know. Can an application running under a less privileged account start a process executing another application under an administrative account?