Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

Need Information on ASP.NET Application Thead Safety

Posted on 2014-09-20
1
Medium Priority
?
313 Views
Last Modified: 2014-10-09
Greetings,

I will be building an ASP.NET application to process orders in a multi-user environment, and I am thinking about thread safety considerations with the class model and usage in my design.   This application will access a DB2 database on an IBM iSeries platform on the back-end, using the IBM DB2 data provider for .NET.  

In a nutshell, the page (UI) classes will create local instances of business-layer classes (order, customer, etc.), which in turn, will contain references to data-layer classes that utilize the IBM .NET data provider to read and write data.  So, the overall design of the program flow will be:
 
Web UI (page classes) --Ref--> Business Classes (DLL) --Ref--> Custom Data Layer (DLL) --Ref--> IBM .NET Data Provider --accesses-->) DB2 database (IBM i Series)
 
With this design model, I need to know what considerations should be addressed regarding thread safety, to avoid problems in a multi-user environment.  I have only a few shared public functions in a global module, but these do not affect data in any way.  They are used to perform fixed calculations or return static information from fixed lists, config file settings, etc.  
 
In my page code-behind, I'll be creating class instances that will handle the actual work and business logic.  These will be private to the page, and destroyed at the completion of the page life cycle.  Example:  The EnterOrder class (EnterOrder.aspx) references three business objects…
 
Public Class EnterOrder
    Inherits ProtectedOEWebPage   <--- (custom class; inherits from System.Web.UI.Page)
 
    Protected cobjOrder As Order    <---- (classes in referenced business object DLL)
    Protected cobjCustomer As Customer
    Protected cobjItem As Item

 
Then, in the Page_Load event, to load data for an existing order:
 
    cobjOrder = New Order()
    cobjOrder.Load(OrderID)   <-- Passed in query string for existing order
 
In the Order.Load event:

   iDB2Connection connection = new iDB2Connection(ConnectionString);   <-- from web.config
   iDB2Cmd = new iDB2Command("CALL oeGetOrder( ? )", connection);  <-- OrderID passed as input, stored procedure on IBM i Series
   iDB2DataReader driDB2Reader = iDB2Cmd.ExecuteReader();

  ... <process data reader and return record to calling function> ...


Do I need to be concerned with thread safety using this model, when multiple users are accessing the application, since business object variables are declared as protected within the page class?  Would IIS not create a separate, protected instance of each page class and referenced objects for each user session?  This application will, for the most part, be using Ajax posts to update and retrieve data, instead of page post backs. For example, user types a customer ID, and tabs out of that field.  An Ajax post is triggered, the customer ID is validated with a database call, and if valid, the ID is updated in the order table and the customer name is also refreshed on the page.  I need to ensure that this kind of end-to-end process is thread safe and without potential for conflict between users.

To summarize:

1.  Is this design thread-safe?
2.  As IIS handles multiple instances of the application and requests to read/update data from the users, will it segregate/protect instances of objects that are created for each session?
3.  If static shared functions or methods are used, should they be used sparingly, and if so, in what situations are they considered acceptable?
 
Thank you in advance.
0
Comment
Question by:bm5034
1 Comment
 
LVL 25

Accepted Solution

by:
apeter earned 2000 total points
ID: 40356402
1. It is thread safe. You are following common practice 3tier model.
2. For each user request, there will be a separate thread to process so the object instances are safe across users.
3.static methods are thread safe by default.

Just thought will reiterate which you might have already doing.

Dispose your connection objects or any resources consumed throught the project.
Cache static values in the sever to minimise the database hits.
0

Featured Post

Windows Server 2016: All you need to know

Learn about Hyper-V features that increase functionality and usability of Microsoft Windows Server 2016. Also, throughout this eBook, you’ll find some basic PowerShell examples that will help you leverage the scripts in your environments!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

When it comes to security, close monitoring is a must. According to WhiteHat Security annual report, a substantial number of all web applications are vulnerable always. Monitis offers a new product - fully-featured Website security monitoring and pr…
No other job is as rewarding and demanding as building an iPhone app is. It is not really in the hands of the developer for the success of an iPhone app. Many factors operate jointly for every iOS application's success in the market.
This video teaches users how to migrate an existing Wordpress website to a new domain.
Learn how to set-up custom confirmation messages to users who complete your Wufoo form. Include inputs from fields in your form, webpage redirects, and more with Wufoo’s confirmation options.
Suggested Courses
Course of the Month13 days, 7 hours left to enroll

578 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question