DCOM how to? please help

[trungluu]

Hi,

Could you please describe clearly to me what is a DCOM process? i mean when a client call a DCOM (on server) by Createobject(...) statement. What will happen? and When client call a method of Object. What will happen? Is DCOM use a message queqe? Do i care about concurrency on multiple user envirement or not (The COM will take care it, is it right? Do I need to lock record when I edit it in a COM?).

I have a DCOM. When the client call it many times (about 3000 times). It will be shutdowned. could you please tell me why?

Thank you very much,

Trung Luu

[deja]

hi there,
DCOM (Distributed COM) is an application protocol designate for communication between COM objects running on remote machines.
DCOM uses RPC above TCP/IP to transfer binary data between clients and server components (the original name is ORPC - Object RPC).
there r various ways to use DCOM (explicitly or implicitly).
for instance, when u put COM object under COM+ application, then produce proxy and install it on a client machine, the MSI installation program automatically create CLSID with keys that points to the remote computer (with COM+).
u can also register AcitveX EXE on a server (or put DLL in a surrogate just like COM+ does) and take care by yourself to configurating the clients.
the main consideration with DCOM is performance. since your clients invoke methods or properties on the remote server, each call is very expensive, so when ever possible reduce the calls u make to server. it means that pass paramters in methods instead of using properties calls.
also do not pass arguments by ref, only by val. because COM use marshaling technique, passing parameter byref causing the values go forth and back. use it only when u have to chabge the value at the server.

[trungluu]

Hi Deja,

Thank you very much for your help.

Trung Luu