Bringing experience to 3000 migrations
March 20, 2006
A request for migration advice drew broad and ample response on the 3000 Internet newsgroup this month. The caliber and quantity of the response shows the community is moving along on its transition path, a good deal more openly and frankly than in 2004 and earlier. Nearly everybody was caught by surprise at the pace of migration among the 3000 customers — except the customers, who knew how integrated the 3000 has become with their business success.
A lot of the users' reports about databases revolved around swapping in Eloquence. John Pitman, writing from the IT operations of Ryco Hydraulics, said his company is working through the move from IMAGE on the 3000 to the Eloquence database on HP's Unix servers:
We have started down the Eloquence/C path on HP-UX some time ago. Having many C programs already under MPE, that decision was pretty easy. We got a free copy of Gnu C, and once we worked out how the libraries worked, it got easy. Some of the IMAGE access routines had some OS conditional code added; now we have over 100 programs with only a few conditional compiles in them that compile and run on either system. This is what you should head for with whatever language you use, so you don’t have two source bases to maintain continuously while you convert.
Pitman said he's been working with test versions of the main databases, "STOCK.TEST” as well as “STOCK.PRODN.” Each program’s open routine for HP-UX demands a variable exist to specify which base to open, which for normal users is done by the logon menu, so we can have both bases coexist safely."
Users agreed that creating Eloquence databases is easy and quick, though Ryco hasn't moved its largest 4Gb database. "Marxmeier are also pretty responsive to requests for help with the product," he added, "and it's certainly much cheaper than Oracle and others." He outlines the complications:
The only traps we have met so far are the need for all DBGETs to read complete records, item list subsets are/were not supported — a feature we used heavily in our old Basic code. Due to the level at which we have the C calls come in, there is a problem using TPI sequenced retrieval, but I don’t think it will be too hard to correct.
John Hohn, a migration consultant and vendor of a database migration tool at Comp Three, noted that moving to SQL from IMAGE might seem daunting, but it can deliver opportunities as a reward for the hard work. Contrary to some advice, Hohn said doing a complete job the first time through has benefits not easy to see at first:
As long as you’re in there re-engineering, do it right the first time; the downstream payoffs (some known now; most to be realized as the industry continues to evolve) are enormous.
I think people are afraid of writing SQL, but it’s not that hard once you get used to it. There are many advantages to SQL; one that we found is, by rewriting our complicated reports to not use cursors (doing intermediate summations with unions instead of programmatic adding up of numbers inside cursor loops) we can complete reports in seconds (yes, seconds!) that used to take 20-30 minutes on the HP3K.
But the real reason to go with SQL are the tools — which will get better and better and remain cheap or free.
Dave Waroff of the San Juan Unified School District testified to the comfort in making Eloquence the first migration landing spot:
Eloquence is the most direct replacement for TurboImage outside of MPE. If you’ve got COBOL programs with VPlus, conversion can be a trivial effort (given tools that are available). JCL can be replaced with native scripting on any system.
This combination provides the easiest porting, and an environment most similar to the original. It’s more comfortable.
Bookware's Peter Osborne even noted that his organization (bookware3000.ca) has moved 800,000 lines of 3000-based COBOL code and IMAGE/SQL access to Eloquence on Debian Linux. "This combo isn’t usually considered for larger operations," he said," as they like to be backed by large vendors.
Ray Shahan of School Specialty said that a migration of under a year "no matter what solution you go with for the migration... is a bit of an aggressive (umm, dare I say...unrealistic) goal."
School Specialty is "looking to see if anyone else has outsourced and succeeded — so we can see if outsourcing our legacy system maintenance is another option we can add to the analysis regarding what to do about migrating." As for advice on where to go or what to do, he says:
Listen to all of the sales people that you can, and about every product/solution that you can find the time for. All salespeople represent some part of a good solution, but the trick is to weed through all the good to find the bad parts of each solution (and many salespeople seem to lack the understanding of the negatives of their product/service).
I mean no disrespect to sales folks (I consider them a vital necessity), but salespeople will almost always have a slanted view of their product/service, so you need to listen to all of them to get a better overall picture. If you listen to only the first salesman, then you may pay for a dump truck when all you needed was a pickup, but the final result will actually be a shovel.
Finally, try to locate any user forums (like this list) for the products/services you are looking at to see what info you can find.