Large monolithic applications can always be modularized around business capabilities too, although that's not the common case. Certainly we would urge a large team building a monolithic application to divide itself along business lines. The main issue we have seen here, is that they tend to be organised around contexts. If the monolith spans many of these modular boundaries it can be difficult for individual members of a team to fit them into their short-term memory. Additionally we see that the modular lines require a great deal of discipline to enforce. The necessarily more explicit separation required by service components makes it easier to keep the team boundaries clear.
One company organised in this way is . Cross functional teams are responsible for building and operating each product and each product is split out into a number of individual services communicating via a message bus.
This emergency plan is designed to be carried out by building-based first responder teams, specifically teams trained for onsite medical emergency response (the team members are building security employees).
A powerful teambuilding exercise for medium sized groups. Participants must touch the randomly placed numbers, in sequence, within a given time frame in multiple attempts.
A team building exercise based on the icebreaker "". Groups are challenged to juggle as fast as possible. Invite group to "tender" a time they can deliver.
Perhaps the apogee of decentralised governance is the build it / run it ethos popularised by Amazon. Teams are responsible for all aspects of the software they build including operating the software 24/7. Devolution of this level of responsibility is definitely not the norm but we do see more and more companies pushing responsibility to the development teams. Netflix is another organisation that has adopted this ethos. Being woken up at 3am every night by your pager is certainly a powerful incentive to focus on quality when writing your code. These ideas are about as far away from the traditional centralized governance model as it is possible to be.
For the microservice community, overheads are particularly unattractive. That isn't to say that the community doesn't value service contracts. Quite the opposite, since there tend to be many more of them. It's just that they are looking at different ways of managing those contracts. Patterns like and are often applied to microservices. These aid service contracts in evolving independently. Executing consumer driven contracts as part of your build increases confidence and provides fast feedback on whether your services are functioning. Indeed we know of a team in Australia who drive the build of new services with consumer driven contracts. They use simple tools that allow them to define the contract for a service. This becomes part of the automated build before code for the new service is even written. The service is then built out only to the point where it satisfies the contract - an elegant approach to avoid the 'YAGNI' dilemma when building new software. These techniques and the tooling growing up around them, limit the need for central contract management by decreasing the temporal coupling between services.
Teams building microservices prefer a different approach to standards too. Rather than use a set of defined standards written down somewhere on paper they prefer the idea of producing useful tools that other developers can use to solve similar problems to the ones they are facing. These tools are usually harvested from implementations and shared with a wider group, sometimes, but not exclusively using an internal open source model. Now that git and github have become the de facto version control system of choice, open source practices are becoming more and more common in-house .
Working with Team Results, I.T. department staff identified a key area of choice and control – they could take charge of ensuring their own high-value marketability across the I.T. community, the business community and the business media after a very successful sale and handover of the Yellow Pages business. The team then focused on using the program to develop tested and proven strategies for the short-term unification of a group of professionals to achieve world-acclaimed performance.
An academic paper was written on this work by Team Results and delivered at Johns Hopkins University, leading to a collaborative project in cutting-edge team dynamics research with UCLA. This paper, and further information on current Team Results’ thought- and practice- leading research activities, can be found in the section.
We cannot say there is a formal definition of the microservices architectural style, but we can attempt to describe what we see as common characteristics for architectures that fit the label. As with any definition that outlines common characteristics, not all microservice architectures have all the characteristics, but we do expect that most microservice architectures exhibit most characteristics. While we authors have been active members of this rather loose community, our intention is to attempt a description of what we see in our own work and in similar efforts by teams we know of. In particular we are not laying down some definition to conform to.
These frustrations have led to the microservice architectural style: building applications as suites of services. As well as the fact that services are independently deployable and scalable, each service also provides a firm module boundary, even allowing for different services to be written in different programming languages. They can also be managed by different teams .