System Admin

10-Aug-07 8:25

I'm working on a small Windows application that will, among other things, periodically connect to some databases (mostly SQL Server) to determine that the databases are available. It's basically an early warning system in case of system outages.

The problem is that some of the databases are ones that the average user doesn't use and has no access to, so connecting and opening will always fail for them.

What I need to be able to do is have the application use different credentials while still using Windows Authentication, I don't want to change the connection strings.

My first thought was to have two processes: one in the background gathering information and storing it in an XML file, the other displaying the information, but I'd prefer to have only one process involved.

I was hoping I could have the application run under some other user, but I haven't figured out how.
The closest I came required the user to type in the password of the other user, which is not a clean solution.

I also tried setting the System.Threading.Thread.CurrentPrincipal, but although it didn't fail, it also didn't work.

Any other ideas?

Dave Kreskowiak10-Aug-07 8:43

Dave Kreskowiak

10-Aug-07 8:43

Why go through the entire permissions complication at all? Create a web service that connects to the database using it's own security and connection string. The applications would, every once in a while, just ask the web service if everything is OK.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

PIEBALDconsult10-Aug-07 9:13

10-Aug-07 9:13

It adds an extra layer of complication? It would fail if IIS and/or the Web server were down even though the database server and database may be healthy?

I'd prefer to have as few layers as possible.

Dave Kreskowiak10-Aug-07 12:16

Dave Kreskowiak

10-Aug-07 12:16

PIEBALDconsult wrote:
It adds an extra layer of complication?

So does impersonating a second ID. The difference is in which one is simpler to support.

PIEBALDconsult wrote:
It would fail if IIS and/or the Web server were down even though the database server and database may be healthy?

The other problem is that your querying the database for a "health status", when if the database is down, that query will also fail, just as a normal user query would. I fail to see the benefit.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

PIEBALDconsult11-Aug-07 3:40

11-Aug-07 3:40

The users are internal, I don't want a failure simply because IIS or some other system is down.

Craster13-Aug-07 0:18

Craster

13-Aug-07 0:18

Run the health-check part of the app as a windows service. You can then specify the credentials.

PIEBALDconsult13-Aug-07 5:31

13-Aug-07 5:31

Yeah, that was my first thought, I already have some stuff like that, but I was hoping for something simpler.

PIEBALDconsult14-Aug-07 6:59

Formating &amp;amp; Reinstalling the OS [modified]

14-Aug-07 6:59

I think it's a bit kludgy, but it works...

In the Main, if the current username isn't the username under which I want to run, I instantiate a System.Diagnostics.ProcessStartInfo, set the appropriate values, and use it to start a new process.

tonymathewt8-Aug-07 23:53

tonymathewt

8-Aug-07 23:53

Does formatting and reinstalling the OS affect the hardisk or any other component of a PC anyway?

Craster9-Aug-07 0:13

Craster

9-Aug-07 0:13

Do you mean does it do it any physical harm? I suppose any write operation to a disk brings it closer to its eventual end of life, but not in any noticeable way.

tonymathewt9-Aug-07 0:39

tonymathewt

9-Aug-07 0:39

Exactly. Does formatting do anything more than just ordinary write operation?
Thankyou.

Craster9-Aug-07 0:57

Craster

9-Aug-07 0:57

I believe a full format will write once to every sector on the disk, whereas a 'quick format' will just wipe the file allocation table, so all the data remains on disk but cannot be identified by the OS.