PCMEF is an architecture style presented in the book Practical Software Engineering by Maciaszek and Liong. The layers are: P: Presentation C: Controller M: Mediator E: Entity F: Foundation. It is some kind of enchancement compared with MVC - architecture. I recommend it to interactice, data and communicating - oriented purposes. I...
Why do people say that business logics should be implemented on the server side code (e.g. EJB) and not on the client application code? The example that I have in mind is a business object validation on a EJB based architecture. Does it really have to be delegated to the EJB or is it ok to run it on the client before the object is sent...
I'm attempting the example from the excellent "How Do I" video for MVVM by Todd Miranda found in MSDN. I'm trying to adapt the example for my learning purpose. In the example, he has a ViewModel called EmployeeListViewModel. Now if I want to include Departments, should I create another ViewModel such as DepartmentListViewModel? Th...
Hi I want a sample that does following: Database <-> Data Access + Cache <-> Business logic <-> UI so basically everything you want from database should be accessible from cache, if it's not in cache, underlying data access layer will populate if and return it otherwise returned from cache is there any disadvantage? in what scenerios t...
I have been reading that direct access to a SQL Server database over the Internet is insecure, so I am wondering what intermediary I can and should use between the client and the server. What are the best practices in terms of security and performance? ...
Hello Everyone, we have a product that work as standalone and Clickonce , we created some components as addins in the system (based on microsoft System.addin) we need a mechanism to update this addins on the customers in the two cases stand and click once I'm thinking for the stand alone we just send the customer a CD to update the ad...
I'm making an open source C# library for other developers to use. My key concern is ease of use. This means using intuitive names, intuitive method usage and such. This is the first time I've done something with other people in mind, so I'm really concerned about the quality of the architecture. Plus, I wouldn't mind learning a thing or...
Currently my employer deploys a web application over 3 servers. DB - No public route Web Service DAL - No public route Web Server - Public route The reason for this is the theory that if the web server is compromised, they don't arrive at the DB directly, but instead arrive at the DAL box. To my mind, as the DAL box and Web Sever bo...
Assuming that I must deploy an asp.net app over the following 3 servers: 1) DB - not public 2) 'middle' - not public 3) Web server - public I am not allowed to connect from the web server to the DB directly. I must pass through 'middle' - this is purely to slow down an attacker if they breached the web server. All db access is via sto...
I want to divide business layer (BLL) of an asp.net application into multiple components. Each component is a .NET class library which is compiled as a standalone DLL. These components should have their own configuration files. For example "MyNameSpace.Users.dll" contains classes about users of the website and there's a password policy t...
Hi: I'm trying to clear up a miscomprehension of the layering of an application. Think I may have something wrong... Up till now, I've only seen smallish apps and websites, each broken down as Data Layer, Services Layer, UI Layer. When WCF was involved, A second 'services' layer was inserted, with remote Proxies. The Data layer conta...
Background I'm working on the architecture for a cloud-based LOB application, using Silverlight for the client, WCF, ASP.NET/C# for server and SQL Server for storage. The data model requires some flexibility per user (ability to add custom properties and define validation rules for them, for example), and a hybrid EAV/CR persistence mod...
Task: Create a system which can produce large amount of tasks (independent pieces of work) in a minimal amount of time. Solution: The system consists of 2 parts: Dispatcher and Worker (WCF service). Dispatcher distributes work between multiple instances (1 - n) of Workers, physically located on several machines. It is needed to distri...
Which is the best place to handle the exceptions ? BLL, DAL or PL ? Should I allow the methods in the DAL and BLL to throw the exceptions up the chain and let the PL handle them? or should I handle them at the BLL ? e.g If I have a method in my DAL that issues "ExecuteNonQuery" and updates some records, and due to one or more reason, ...
I have an MVVM application I am developing that is to the point where I'm ready to start putting together a user interface (my client code is largely functional) I'm now running into the issue that I'm trying to get my application data to where I need it so that it can be consumed by the view model and then bound to the view. Unfortu...
I have a python script that accepts a file from the user and saves it. Is it possible to not upload the file immediately but to que it up and when the server has less load to upload it then. Can this be done by transferring the file to the browsers storage area or taking the file from the Harddrive and transferring to the User's RAM? ...
I have a task to build a prototype for a massively scalable distributed shared memory (DSM) app. The prototype would only serve as a proof-of-concept, but I want to spend my time most effectively by picking the components which would be used in the real solution later on. The aim of this solution is to take data input from an external s...
I just wanted to ask if we can access an external MySQL server from Google App Engine... ...
Hi, We are designing a new version of our existing product on a new schema. Its an internal web application with possibly 100 concurrent users (max)This will run on a SQL Server 2008 database. On of the discussion items recently is whether we should have a single database of split the database for performance reasons across 2 separate ...
I am writing a design document and people on my team are willing to do the move from ASP.NET WebForm to ASP.NET MVC. This is great, but I have a hard time to understand how MVC workswith in a 3-tier (Data Layer, Business Layer and Presentation Layer) architecture. Can we say that the Model, View and Controller are part of the Presentati...