Memory allocation for application called from Command Line

shaimil · Post by **shaimil** » Wed Mar 16, 2005 9:50 am

Can anyone explain the following.

I am making a call to an application called QAS (address cleansing) from within Datastage, using the command line stage. When this runs it is allocated upto 3MB of memory.

When I make the same call from the Windows command line the QAS app is allocated upto 300MB.

I've worked around this, but was just curious as to the difference.

Regards
Shay

ArndW · Post by **ArndW** » Wed Mar 16, 2005 10:36 am

Shaimil,

if the QAS application does the same thing in both cases, it probably uses the same amount of memory - but due to the different calling methodologies you might be seeing different amounts displayed. How are you ascertaining how much memory both processes are using (please don't tell me you are using the Task Manager

)? You can use the Administrative Tools -> Performance monitoring to get a bit more information on the types and amounts of memory used.

shaimil · Post by **shaimil** » Wed Mar 16, 2005 10:57 am

A bit of everything, but QAS actually launched a front-end showing the throughput and memeory usage. We have also checked this against the Performance Monitor.

Not only this, but visibly (in duration) it takes hours longer from within DS then from the command line.

ArndW · Post by **ArndW** » Wed Mar 16, 2005 12:04 pm

That is strange behaviour indeed. DataStage doesn't really do any magic; it just opens up a cmd shell and executes the command. If you wish to try it, you can TELNET to your DS server, login to datastage (use the "UV" account when it prompts you for it), then from the ">" prompt execute a "DOS" command to put you into a shell and see how long your QAS run takes. This is almost exactly what DS does in the background. Perhaps you are getting some sort of contention, although I can't imagine what.