Support for mobile applications is a key component of every company’s IT strategy today. For many companies, extending existing applications to support mobility can be a real challenge though, since the needs of a mobile client are so different from traditional PC-based clients.
Mobile Environment Dramatically Different from Three-Tier Architecture
Since the introduction of the web browser in the early ’90s, web applications have been developed using a traditional three-tier architecture; a web browser on the client side, with business logic running on a server accessing a database. This worked well when the web client was a PC running on a high speed LAN behind a firewall, incorporating a large display and a powerful CPU.
However, the environment that mobile applications operate in is very different. Access often occurs from outside the firewall via unreliable and slow cellular networks, and from using devices that can have reduced processing capabilities and small displays.
The average web page today is slightly more than 1.5 MB in size. While this is fine for a PC, mobile devices will choke on page loads that large—and performance and user experience suffers. Clearly, we need to rethink how web applications are built so we can support these unique needs.
A New Way to Build Mobile Applications
Forrester Research has proposed a more modern architectural approach to building mobile applications using a four-tier model that breaks the three-tier model into two layers, providing for a more fine-grained and service-oriented approach to developing business logic and delivering content.
Using the four-tier approach, developers write applications that are composed of fine-grained services, typically accessed via REST APIs. Instead of writing monolithic applications that bundle business logic, client access, and content delivery, these capabilities are implemented in separate layers. This approach makes it much easier to integrate third-party or partner content, or make changes to existing applications.
Performance is so critical to the success of a mobile application; to get great performance, you have to focus on both how you build an application and how you manage the “digital last mile,” the bridge between your internal IT systems and the devices accessing your applications over the web. One of the key benefits derived from using a four-tier architecture is the flexibility you get in handling the end-to-end flow of data and content between backend enterprise applications the mobile devices.
TIBCO’s approach to the development and integration of mobile applications in the enterprise aligns well with the core concepts Forrester presents in this paper. Take a look at it and let us know what you think. And stay tuned, we’ll be talking a lot more about this in the coming weeks.