Conference ulysse::rdb_vms_competition

1062.0. "Adabas to VAX migration" by WDFRT1::BREWMN::BREWIS () Fri Jan 17 1992 14:08

Hello,

I have a customer interested in determining how difficult it would be to 
migrate (pickup and move with minimal changes to the application) an 
Adabas/Natural/Complete application running on an IBM 4381 running DOS 
under CICS to the VAX platform.

The customer has minimal information available to him about the details 
of the application because this will be a power play move on his part to 
migrate the application from its current home (big blue haven) to the 
sometimes treacherous waters of VAXdom.

So, my customer would like to know the following:

1.	Has Digital or its customers ever done this before?  If so with 
	what amount of success?

2.	The application is using abnout 3 Mips of an 8 Mip 4381, how 
	much VAX will he needed in terms of VUPS?  (His question, not 
	mine).  

	Please save your breath on the speech about MIPS, VUPS, 
	comparisons of the two and the importance of throughput as the 
	real measurement of acceptable performance: I understand and 
	agree,  HOWEVER, if anyone has information in general about how 
	much of an IBM the application used to use and then how much of 
	the VAX the migrated application now uses we may be able to give 
	the guy a feel for his task.  I've already set the stage that 
	these types of comparisons are greatly lacking of any real 
	significance.  He understands and does not plan to purchase a 
	processor based on a statement about comparative Vups to Mips, but 
	does need to have this information to convince the rest of the 
	corporation (IBM-oriented folks) that he is getting a much 
	better deal using the VAX.

3.	He likes Rdb and has RTO at his site.  However, to make his coup 
	attempt successful he is somewhat concerned about the time it 
	would take to convert the Natural application and the database 
	to Rdb.  So two questions:

	a.  How quickly could an Adabas/Natural/Complete application be 
	    migrated to the VAX using the same products/tools?  Any 
	    known gotchas?

	b.  How would that same migration proceed if the database were 
	    to be Rdb instead of Adabas?


4.	They use Complete (Adabas's TP Monitor, I think) on the IBM.  
	What types of problems might this cause for migration of the 
	application from IBM to VAX?  If usinng Adabas and Natural or if 
	using Natural and Rdb?

5.	Is there anyone who has done some portion of this before?  
	Digital employee or customers are acceptable.

Thank you,

Rick

    Your questions are more appropriate for Software AG. They are the
    people who should have the most experience on both the platforms you
    mentioned. 
    
    Also, try contacting Chris Butler in Fredricton, New Brunswick Canada
    (he is in ELF). A customer of his recently put their Natural/Adabas
    applications on the VAX platform.

Ken,

Thanks for your reply.  I contacted Adabas right after entering this note. 
The contact said that Natural/Adabas applications port very easily from 
the IBM to VAX environment without modifications to the Natural application
or the database.  The contact also indicated that the application migration 
can occur independent of Software AG's Complete product.

Side note:	Complete is like TSO and/or ROSCOE on the IBM system.  IT
		runs independent of CICS (in other words, not as a CICS
		transaction).  Complete is available on the IBM platform only.

My contact said that they use a product called Convert to read the IBM EBCDIC
tape to convert the Natural Application and the Adabas database to ASCII. Once
Convert is completed, just compile and complete a few manual steps to finish 
the setup.  Most of these center around the creation of directories, 
subdirectories, logicals, and symbols.

Performance

Natural/Adabas performance is purportedly comparable to the figures we publish
for active (not subscribers) ALL-IN-1 users supported by our processors.  He
recommended about 1/2 MB memory per user and, of course, the usual cautions
about spreading database I/O across as many spindles as you can.

Rick