[tl;dr Enterprise modularity is the state-of-the-art technologies and techniques which enable agile, cost effective enterprise-scale integration and reuse of capabilities and services. Standards for these are slowly gaining traction in the enterprise.]
Enterprise Modularity is, in essence, Service Oriented Architecture but ‘all the way down’; it has evolved a lot over the last 15-20 years since SOA was first promoted as a concept.
Specifically, SOA historically has been focused on ‘services’ – or, more explicitly, end-points, the contracts they expose, and service discovery. It has been less concerned with the architectures of the systems behind the end-points, which seems logically correct but has practical implications which has limited the widespread adoption of SOA solutions.
SOA is a great idea that has often suffered from epic failures when implemented as part of major transformation initiatives (although less ambitious implementations may have met with more success, but limited to specific domains).
The challenge has been the disconnect between what developers build, what users/customers need, and what the enterprise desires – not just for the duration of a programme, but over time.
Enterprise modularity needs several factors to be in place before it can succeed at scale. Namely:
- An enterprise architecture (business context) linked to strategy
- A focus on data governance
- Agile cross-disciplinary/cross-team planning and delivery
- Integration technologies and tools consistent with development practices
Modularity standards and abstractions like OSGi, Resource Oriented Computing and RESTful computing enable the development of loosely coupled, cohesive modules potentially deployable as stand-alone services and which can be orchestrated in innovative ways using many technologies – especially when linked with canonical enterprise data standards.
The upshot of all this is that traditional ESBs are transforming..technologies like Red Hat Fuse ESB and open-source solutions like Apache ServiceMix provide powerful building blocks that allow ESBs to become first-class applications rather than simply integration hubs. (MuleSoft has not, to my knowledge, adopted an open modularity standard such as OSGi, so I believe it is not appropriate to use as the basis for a general application architecture.)
This approach allows for the eventual construction of ‘domain applications’ which, more than being an integration hub, actually hosts the applications (or, more accurately, application components) in ways that make dependencies explicit.
Vendors such as CA Layer7, Apigee and AxWay are prioritising API management over more traditional, heavy-weight ESB functions – essentially, anyone can build an API internal to their application architecture, but once you want to expose it beyond the application itself, then an API management tool will be required. These can be implemented top-down once the bottom-up API architecture has been developed and validated. Enterprise or integration architecture teams should be driving the adoption and implementation of API management tools, as these (done well) can be non-intrusive with respect to how application development is done, provided application developers take a micro-services led approach to application architecture and design. The concept of ‘dumb pipes’ and ‘smart endpoints are key here, to avoid putting inappropriate complexity in the API management layer or in the (traditional) ESB.
Microservices is a complex topic, as this post describes. But modules (along the lines defined by OSGi) are a great stepping stone, as they embrace microservice thinking without necessarily introducing distributed systems complexity. Innovative technologies like Paremus Service Fabric building on OSGi standards, help make the transition from monolithic modular architectures to a (distributed) microservice architecture as painless as can be reasonably expected, and can be a very effective way to manage evolution from monolithic to distributed (agile, microservice-based) architectures.
Other solutions, such as Cloud Foundry, offer a means of taking much of the complexity out of building green-field microservices solutions by standardising many of the platform components – however, Cloud Foundry, unlike OSGi, is not a formal open standard, and so carries risks. (It may become a de-facto standard, however, if enough PaaS providers use it as the basis for their offerings.)
The decisions as to which ‘PaaS’ solutions to build/adopt enterprise-wide will be a key consideration for enterprise CTOs in the coming years. It is vital that such decisions are made such that the chosen PaaS solution(s) will directly support enterprise modularity (integration) goals linked to development standards and practices.
For 2015, it will be interesting to see how nascent enterprise standards such as described above evolve in tandem with IaaS and PaaS innovations. Any strategic choices made in these domains must consider the cost/impact of changing those choices: defining architectures that are too heavily dependent on a specific PaaS or IaaS solution limits optionality and is contrary to the principles of (enterprise) modularity.
This suggests that Enterprise modularity standards which are agnostic to specific platform implementation choices must be put in place, and different parts of the enterprise can then choose implementations appropriate for their needs. Hence open standards and abstractions must dominate the conversation rather than specific products or solutions.