|D. Britton Johnston|
For a while it was assumed that persistent broadband wireless connectivity would solve the problem of application access for mobile users. With a "wireless everywhere" infrastructure and an Intel Centrino-enabled notebook, workers anywhere were supposed to be able to connect to their centralized applications. Today, however,
Thus, the ball is back in the court of the application developer. Without the assumption of persistent connectivity to the centralized data center, applications must be architected to sustain "roaming" in and out of constant connection. Applications should store updates locally and intelligently synchronize with the data center when connected. So instead of populating the user screen with error messages or making the application totally unavailable, the enterprise application is brought on the road. After all, with most key business processes supported by critical enterprise applications, it makes little sense for them to be unavailable or unstable when used in mobile capacities.
Moving forward, application architectures must adapt to the new realities of the enterprise and become inherently mobile. These "mobilized" applications will reduce the role of the network from "application lifeline" to "application change conduit," and enable workers to always have access to their applications, independent from the state of network connectivity. This architecture also ensures that remote offices are not impacted by technical issues in the network, or the corporate data center, so they can stay up and running at all times.
There are a number of market forces at work today that are breaking down these barriers to the distributed application model. For one, cheap disk storage and powerful PCs make it possible and cost-effective to distribute, store and process vast amounts of data anywhere in the enterprise. Databases used to be centralized out of necessity. Today, however, it is quite possible to, for example, put the entire customer database on a salesperson's notebook. Additionally, today's corporate emphasis on disaster recovery and high availability, combined with slashed IT budgets, makes an inherently redundant decentralized application infrastructure far more attractive and cost-effective than the typical "fail-over" or "hot-standby" capital-intensive backup schemes used today.
Finally, open source databases and application servers enable companies to overcome the cost barriers inherent in traditional vendor licensing schemes, making it economically possible to deploy these system components in multiple locations at the edge of the network.
In concert, these factors prime the landscape for a new breed of mobilized applications, in which applications and their data can be distributed locally to remote offices and end-user platforms to eliminate persistent connectivity as a critical architectural component. The main question is, how?
How to MobilizeThe birth of heterogeneous bi-directional replication technologies provides the most powerful way yet developed for distributing and synchronizing databases across the enterprise. The fact that these technologies are now available as general-purpose software allows a new approach to building distributed software solutions, so they are totally mobilized. The heterogeneity of these technologies enables cost-effective distributed architectures, since companies can use any combination of databases, and because they are bi-directional, they enable companies to create incredibly redundant architectures populated by perfectly replicated systems.
This new class of distributed database applications does not eliminate the need for large centralized databases, but rather provides a robust environment in which data can be distributed across an enterprise providing end users with better quality of service and eliminating the dangerous single point-of-failure inherent in centralized database application architectures. By doing this, companies can preserve their investment in their current application architecture, but enhance it so it is fully mobilized using bi-directional heterogeneous replication technology.
It's time for business applications to get out of the centralization time warp. Developers should take a long, hard look at their applications and evaluate the benefits of mobilizing them. Would end-users benefit if your applications could continue to operate disconnected from a central database? Do you need to provide mobile workers full-function applications and see no way to do so in a world dominated by centralized databases? Examine your application architecture, and you may find that the assumptions you have made about data are no longer valid.
In a world where advanced bi-directional heterogeneous replication technologies let you move data to the user, and keep that data synchronized without writing complex application code, and without having the build a reduced function application, the centralized application model seems as archaic as its forebear – the mainframe architecture. This concept of mobilized applications may seem new today, but technology evolution, combined with market opportunity and competitive pressure, will make it commonplace tomorrow. And at that point, all end-users will expect their critical applications to run disconnected from the network. They will expect to be able to take the enterprise on the road.
About the author:
D. Britton Johnston, Chief Technology Officer, PeerDirect Corporation
Britt has been creating software products for enterprise customers for over 20 years. Today, Britt is spearheading the PeerDirect Distributed Enterprise product line that allows Occasionally Connected Computing (OCC) applications to be deployed globally and managed centrally. PeerDirect's products help organizations overcome challenges directly related to deploying and managing applications in complex environment through the use of distributed computing, data replication, and OCC management technology.
This was first published in June 2004