Overview of Modern Application Architecture Trends and Principles

Although some methods are not the latest, they still provide valuable insights; the article will later introduce Gantner's latest application architecture trends.

Application Architecture Overview

With the continuous emergence of interrelated forces—cloud, mobile, social, and big data—organizations that do not leverage them will face serious business disadvantages in the future.

Architects should consider adapting to these new trends.

Use service‑oriented architecture (SOA), including micro‑service architecture (MSA), to build applications and integrate commercial off‑the‑shelf (COTS) and legacy systems, as well as partner applications and cloud services.

Leverage SOA to provide loosely‑coupled connections between applications and services with different budgets, schedules, requirements, and owner priorities.

Use SOA’s separation of concerns and encapsulation to integrate mobile, social, and cloud data sources with variable structured and unstructured data models.

Adopt event‑driven architecture (EDA), the most critical form of loose coupling.

Ensure development work becomes more agile and incremental.

Consider open computing through open‑source products, open standards, and open data.

Follow best practices from large‑scale websites and look for opportunities to use in‑memory computing and transaction processing based on eventual consistency models.

The following chart shows the application architecture agenda.

Abandoning Three‑Tier Architecture

The layered approach of three‑tier architecture defines applications only in one dimension (Figure 2). All data sources reside at the bottom, all UI logic at the top, and the rest of the application sits in between, creating a linear, one‑dimensional view.

Modern client applications must support a wide range of devices—PCs, netbooks, tablets, smartphones, kiosks, car dashboards, GPS devices, media players, etc.—and often need to expose functionality to other systems such as social platforms, partner applications, media sites, or mash‑ups (Figure 3). In such scenarios, the notion of a single client program directly invoking business logic becomes unrealistic.

We now have multiple dimensions on both the access side and the data‑management side. Business logic in many new applications consists of composite services that depend on multiple sub‑services. Sometimes these services run internally; other times the application must call partner or vendor services, which may be hosted in the cloud.

Given these observations about real‑world application complexity, a well‑described architecture should assume many client programs and devices accessing many business‑logic services, which in turn access other business‑logic services and multiple data‑access/management services.

Discarding Outdated Application Architecture Assumptions

Designers have long based applications on assumptions that conflict with the new paradigms introduced by mobile, social, cloud, and modern information management. It is necessary to abandon these assumptions to accommodate the interplay of cloud, social, mobile, and data.

Discard the assumption that applications depend on a homogeneous environment; design for hybrid‑cloud, highly dynamic infrastructure.

Discard the assumption that an application resides in a single location; allow processes and data to be distributed across multiple jurisdictions.

Discard the assumption that databases enforce process integrity; instead, create integrity‑aware applications that manage business outcomes.

Discard the assumption that applications only use structured data; instead, accommodate diverse media types and multiple data models for similar purposes.

Discard the “record‑centric” assumption; instead, design applications around interpersonal and social communication.

Adopting Application Patterns and Models

The term “application architecture” refers to the structure and organization of an application, including its components and the interaction/dependency model between them. Architects apply architectural patterns and use common models to design applications and define their architecture.

The most directly affected application qualities are:

Maintainability

Robustness

Versatility

Usability

Longevity

Understanding how to use application architecture to deliver these qualities involves three components: paradigms, models, and structure/organization.

Paradigm

An architectural paradigm (or style) provides a high‑level conceptual framework that influences how you design an application, helping ensure the resulting system exhibits the characteristics desired by its owners.

Model

A model is an abstract description and symbolic specification of certain aspects of the real world. Models help people grasp complex systems by presenting a high‑level representation of the most visible aspects. Designers, developers, and stakeholders create increasingly detailed models to understand functional and non‑functional behavior and inter‑dependencies.

Solution architects model four related aspects of a system:

Business capability model – what the organization needs to be able to do.

Business process model – how the organization accomplishes tasks.

Information model – the information the organization uses, processes, or creates.

Service model – the software components that perform the work.

Structure and Organization

The architecture of an application is reflected in its implementation structure and organization, influencing performance, scalability, robustness, flexibility, maintainability, and total cost of ownership.

To assess the quality of an application’s architecture, consider:

Decomposition and granularity of services and composites.

Topology used to define and describe the solution.

Inter‑dependencies among solution components.

Interface specifications and contracts.

Frameworks defined or leveraged.

Implementation details.

Source: https://architect.pub/current-trends-application-architecture