DCOM and XP SP2

watty

Actually most network multi-user apps that use DCOM seem to do because they were standalone apps with COM inside bits of them. Rather than anay understanding of Disitributed Applications or Client / Server.

I wouldn't use DCOM for "TRUE" Client / Server as it is really a "Peer" to "Peer" protocol. Quote " The DCOM "server" application must "logon" to the DCOM "client" application PC."

Thus some DCOM based socalled Client / Server apps I have had misfortune to set up are written without any understanding of DCOM or Security APIs. Often they need lots of "mad" DCOMCOnfig configuration to work.


So will these or most of them "stop working" on XP SP2?

What you think?

P.S. If you can write a VB program calling DCOM to open an instance of Excel on a remote PC, then your PC user acounts / security settings are seriously flawed. (Makes no difference if Domain Controller or not). Note that such a scenario is more likely to work if Peer to Peer file sharing is working BOTH WAYS between the two PCs.

MS claim (in one place) that only PCs that are Domain Members can particapate in DCOM applications..

Actually, create account with SAME NAME and Password on client machine as the DCOM "server" is logged in with, Login iun once with that to make it a "real" account, Make sure you can log in "local" on Console on the DCOM "server" with your client name / password.

Now logon "server" with its normal account and your own PC with its normal account and DCOM will work, EVEN if these two PCs belong to different Domains. With no trust relationships or anything.

watty

Please, I would like some educated comments on this topic.

Also as far as I can see....

DCOM = OLE

Why?
COM was a renaming of OLE with a few extra APIs in the 16bit to 32 bit changeover.

MS claim most COM applications will work as DCOM by adding registry entries.

Obviously DCOM as compared to COM uses extra bits of the OS. But the point is that for the application this is hidden. I think this is a bad route.

I'd rather use ODBC for Client/Server data and any approriate TCP/IP protocol for anything else distributed.
* It work better
* Security easier to understand
* Platform independent (even ODBC is available on non-Windows now)
* More or less secure as required by programmer

How would you tackle security when writing :

* Multiuser Document Management
* Client / Server Database
* Multiplayer game

10000maniacs

Hi Watty,
DCOM is just an extention of the COM model to support communication across networks and the WWW.
When client and component reside on different machines, DCOM simply replaces the local interprocess communication with a network protocol. Neither the client nor the component is aware that the wire that connects them has just become a little longer. A typical security mechanism for DCOM would involve passing some kind of username and password (or a public key)—usually encrypted—to some kind of logon method.
COM+ is just an improved version of COM and Microsoft Transaction Server. Ie Hundreds of bug fixes.

Originally posted by watty


So will these or most of them "stop working" on XP SP2?

Microsoft don't recommend using DCOM for Windows XP. COM+ is the way to go.
Even better .Net encapsulates the COM+ security implementation to make it easier to enable applications work on other machines.