Gossip: Evolution to Enterprise Service Bus

November 15th, 2008

I was involved in a forum discussion regarding ESB, and I’d like to share a small story here.  Once upon a time, there was a Small Bank which was, small.  It had only 8 branches.  The main transaction system was of course the one run on IBM mainframe.  Nobody got fired by using IBM.  Due to recession of economy, there were a lot of delinquencies for personal loans.  Small Bank would need to pay pretty high percentage of the collected amount if it had outsourced the phone collections.  There were also concerns that third-party collection companies were not friendly and might damage the brand image of Small Bank.  As a result, stingy top brasses of Small Bank had no choice but setup phone collection within the company.  The collection module of IBM system was way too pricy, so they decided to try out a PC-based collection system from the Smart Vendor.

A collection system is a very simple system: it fetches the data from mainframe, shows the data on collectors’ computers, stores summaries entered by collectors, and follows every promise that customers made to collectors.  If any promise was broken, it needs to take corresponding measures according to preset business rules.  Fairly easy isn’t it?  The flavors only consist a simple database, a small workflow, and a little bit of UI development.  That type of system existed long enough using client-server architecture: a database server sit on the backend, workflows were divided into DB batches and UI logic, and a VB-based program installed on every collectors’ computer.  Piece of cake no big deal.

Sounds like problem solved.  Well, was the cost low enough?  Good question.  Databases were priced by seat (at least when I were using them in the good old days).  There were at least 100 users, and the license fee tasted a bit bitter.  Installation of that VB-based client on 100 machines created great chances for collectors to take a long enough tea break, which implied hidden cost.  To make things worse, if the client software had had bugs, the computers needed to be patched, which indeed was not a smart idea.  On the other hand, if the client software was pulling too many data from the DB server, network infrastructure would require upgrade, thus another unwelcomed cost.

To assist with the cost reduction concern, Smart Vendor proposed a solution: multi-tier architecture.  There were middlewares consolidating all DB requests, so fewer seats were needed for DB software.  There were web servers hosting front-end UI, which were now web pages.  Collectors used their browsers and navigated to an URL, then they could start their work.  No more software installation, no more excuse for tea breaks.  The last step was centralizing all workflow into application servers, and streamlined app servers, web servers, DB servers, and the system could light up.  Done, cool, awesome cost-effective.

However, the great recession of economy was unforeseen and Small Bank had to take more aggressive approaches to please the Wall Street.  Small Bank was renowned for their professional banking services, not IT services.  This simple little collection system required a vast infrastructure to operate: computer hardware, software, network equipments, dedicated real estate for the equipments, business class network infrastructure, and dedicated workforce to maintain all these.  Everything in this big chain meant cost!  Could we avoid the costs?

Smart Vendor heartly understood the requirements of Small Bank and proposed a shiny, new, catchy solution: cloud computing and enterprise service bus.  Smart Vendor provided data center, equipments, software, network infrastructures, and dedicated IT staff.  All that Small Bank needed to do were to pay subscription fee and to build their DB/workflow/UI based on ESB spec.  Collectors of Small Bank might need to connect to a new URL, if that meant anything.  Done, cool, awesome cost-effective.  Small Bank could then sell the equipments, use cheaper DSL connections, layoff IT workforces, and boost stock price.  This solution was so great.  It was more cost-effective than outsourcing and traditional multi-tier systems.  The only drawback was Small Bank now married with Smart Vendor together forever, and divorsing would be as costly as hell … well, this was not really an issue.  Small Bank could never afford divorsing Smart Vendor even with the client-server system.

So the story ended.  La viva cost down!

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