[DUG] DataSnap/Midas App Server Error

Stacey Verner stacey at cjntech.co.nz
Fri Sep 2 09:48:15 NZST 2005


We have an DataSnap/Midas app server which fails randomly.
 
We can't make it happen no matter how hard we try, but it happens fairly
regularly on our production machine.
 
A little bit of info on the app and app server:

*	The applicaiton is a normal database application.
*	The application also needs to get information from a settings
(metadata) database such as:

	*	Which databases they have access to
	*	What permissions they have on the database etc

*	Instead of connecting directly to the settings database we use
the app server which shares one database connection between all clients.

	*	This means that there is one database connection for
each application instead of 2 which reduces licencing costs

*	We use the borland socket server and a socket connection to
connect to the app server.

	*	When we used a normal DCOM connection each client got
its own copy of the app server, so the settings database connection is
not shared and in effect each application had two connections to the
database.

Sometimes the app server locks up and the clients can't connect.
 
We have a work around that will try app servers on other machines if
this fails which works OK, but if it never gets a connection the all
sorts of odd things happen.
 
Firstly, does anyone have any thoughts on this. Debug ideas etc?
Secondly, when the connection to the app server fails it takes forever
(minutes) to return no matter what I set the socket connection timeout
to.
 
Thanks
 
Stacey
 
Stacey Verner             Ph:   +64-9-4154790
Software Developer        Fax:  +64-9-4154791
                          DDI:  +64-9-4154797
CJN Technologies Ltd.     Email: stacey at cjntech.co.nz
<mailto:stacey at cjntech.co.nz> 
PO Box 302-278, North Harbour, Auckland 1330, New Zealand
12 Piermark Drive, North Harbour, Auckland, New Zealand
Visit our website at http://www.cjntech.co.nz/
<http://www.cjntech.co.nz/>  
 
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