Live-updating .NET DLL's on Citrix: possible or not?

[MarnickTelenet]

We have a Windows .NET application that is running on a Citrix-server.

The application uses stored-procedures on a SQL-server.

We want to stop using stored-procedures because we want to centralise all the logic (insert/update/delete) in a business-framework written in .NET.

This means that the logic moves from the SQL-stored-procedures to DLL's (written in VB.NET).

We see one big disadvantage of this step.

Stored-procedures: we can live-update them (= while a lot of users were using the app on Citrix). Because of that, a lot of logic-updates could be done without the users knew it and without stopping the users using the app.

I'm almost sure we will not be able to live-update the DLL's. A "logic-DLL" will only be updateble after the last user has stopped using the app.

That means: if you move logic from stored-procedure to DLL, you get an update-disadvantage. For every update, even the smallest one, it wil be necessary that all users leave the application so that the DLL's become free for replacing them with a never version.

Is there a solution for this problem??? Is there a way to live-update DLL's on a Citrix-server??? (Same question on a standard terminal server)

 

[chrissie1]

The better solution (and recommend by many) would be to leave the SP's and make your bussiness framework use the SP's. Loosing the SP's will only create a performance drop.

So I suppose the sql-server is on a different server then the citrix server. So why not put the bussines logic framework on that.

Try looking at the csla.net solution lhotka provides and read his book.

Christiaan Baes
Belgium

"My new site" - Me

 

[MarnickTelenet]

Christiaan, thank you!

The configuration is: one separate SQL-server and more Citrix-servers. The application is on every Citrix-machine and connects to the data by ADO.

If we place the bussines logic framework on the SQL-server:

1. What will be the performance and load implication of the SQL-server. Do you have any experience with that?

2. Will it be in that case possible to live update the DLL's like we can easy live update a stored-procedure?

I see you are from Belgium. Me too!

 

[chrissie1]

1. Yes there will be implications, but it depends on the load you already have. It could be less but it could be more, depending on how you implement them. A third server would be nice.

2. Since the Live updat will only affect your DAO's (Data Access Objects) and not the Model (Bussiness objects) it should be possible to live update them togther with the stored procedures.

Al this off course depends on what the load is for this application and if it is really neccessary. But havin a dataaccess layer that that is separate will give you the choise where you put if fysicaly. If you can transport the dataacceslayer from one machine to the other or even put it on each client means it is a good one.

Tja de wereld is klein.

Christiaan Baes
Belgium

"My new site" - Me

 

[MarnickTelenet]

The reason is our company also has develloped web-applications that uses an already written .NET business-framework with the business-logic included in this, and NOT in stored-procedures. All of this exists of DLL's. In a web-application, you can overwrite those DLL's while users are busy, so there the problem does not exists or exist less.

But in our solution, a totally different Windows application that must run on Citrix-servers, we use stored-procedures. One of the big advantages we have is that we can update those stored-procedures live.

Stepping in the business framework means we move code from SQL-syntax (stored procedures) to VB-syntax (DLL's), but finally both wil do the same!

Our current configuration is quite simple:
- SQL-server with data and stored-procedures
- One or more Citrix-servers with the application

It looks that every way to step in the business-framework with trying to keep the advantage of live-updating makes the configuration much more complex.

Because of this motives: is it wrong to continu using stored-procedures? What's your opinion?

 

[chrissie1]

I would still use SP's (for security) and let the datacceslayer use those.

Christiaan Baes
Belgium

"My new site" - Me