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forums.inprise.com · Guest

I got a very strange problem with a datasnap (midas) application written in
Delphi 4.02 :

The application uses midas socket connections with Tclientdataset (connected
with datasource, dbgrid and other stuff) for the client side. On the server
side (physically on a separate "big" computer), we have several COM servers
(based on TRemotedatamodule components) connected to a local Paradox
database, using a BDE Alias. Of course, scktsrvr.exe is running on this
server computer. It may have up to 10 or 20 clients computers simultaneously
connected to the server, each one using up to 4 or 5 Tmidasconnection
connected to scktsrvr. In fact, no more than 10 concurrent connections to
the socket server are really effective.

We had had some problems wih paradox but all were solved, step by step,
sometimes by using workarounds (like systematically reindexing tables, or
periodically stopping the Com server in order to free ther memory).

But there's a new stange problem : sometimes the application hangs on the
sever. And it's very strange. The application seems to be freezed but in
fact, it is running, but, suddenly, very very slowly. It 's looks like when
a process is using 100% of the cpu but no such process at all can be found
in the windows task manager. Windows (2000, up to date) itself is affected
and all become slow (menu, reduce or change windows, etc.)

If I kill the server processes runing on the server it's ok all is coming
back OK. So it comes from my app : midas, BDE, mabe my code ....

Do yo know what can be the reason on this strange problem ?

In some other times. The application become really frozen. And in this case,
I'm sure that it come from the BDE. Indeed, if I run dbd32.exe or
bdeadmin.exe they both ar running (seen in task manager) but in a frozen
mode and the suddenly reappears on the desktop when I stop one of my Com
processes running on the server (and frozen too). It is not always the same
Com process that resolve the problem when it is killed.

Same question ? have you an idea of the cause ? How can I investigate ?

I'm trying to migrate the App on Delphi 6 and plan to get rid of the BDE
(using Advantage Server or other database) and I have another question :

What is the quickest way to migrate from midas to datasnap.
I used some Tmidasconnection connected to D4 RDM with Tclientdataset
connected to Tprovider components.
Now I have to use Tsocketconnections connected to D6 RDM wih Tclientdatast
connected to Tdatasetprovider (no Tprovider in D6).
I try do make my own Tprovider inherited from Tdatasetprovider because
bdeprov.pas doesn't exist in D6. Is is a correct way ? Is there another
better ?

Thanks for your help.

Esteban Pacheco · Guest

Hello,

I will try to give my input bellow: