Tango V8 – An Implementation of Microservices ArchitectureV

Introduction
Our broadly used Tango software is an implementation of a microservice architecture.  Tango was not initially designed to be “microservice”, it was more properly designed to implement a transactional, mission critical, Service Oriented Architecture “that works” (SOATW!). By “that works” I mean, performant, scalable, avoiding contentions and anarchic leeway and sustainable. It is clear that to make it sustainable, a SOA system must include major concepts: a data bus or universal messaging layer to anarchy (meaning the ability to define as many interfaces than relations between services) and a load-balancer in order to avoid contentions or stress points. Some state that these 2 concepts are the key differences between SOA and microservice. However, the definition of microservice is not so clear and sometimes it is nothing more than: “it is not a monolithic architecture”. So, the first thing we will do is define it, then we will outline what applies and what does not apply in Tango and finally we will present Tango v8.

What is a microservice architecture?
A microservice application is a collection of autonomous services, each of them doing one thing well and when combined, work together to provide a global service. Instead of a single complex system (monolithic architecture), the aim is to build and manage a set of relatively simple services that might interact in complex ways. These services collaborate with each other through a messaging protocol.

The idea is quite simple: Having a collection of little ships instead of a huge one. That metaphor is not totally wrong. Lots of little ships are easy to maneuver; if one is delayed the others can progress. However, you can quickly cover more space with your multiple ships and if one is sunk (bad feature, bad design…) the others can still fight. Of course, there are some intrinsic difficulties: first a light fleet requires more coordination; second it is not as easy to make it a robust battleship.

Anyway, microservices promise a better way to sustainably deliver business impact. Rather than a single monolithic unit, applications built using microservices are made up of loosely coupled, autonomous services. Building services that do one thing well avoids the inertia and entropy of large applications.

Properties of microservices are:

• A single microservice should be highly cohesive: it should be responsible for some single capability within an application. Likewise, the less that each service knows about the inner workings of other services, the easier it is to make changes to one service — or capability — without forcing changes to others.
• A microservice owns its data store, if it has one. This reduces coupling between services because other services can only access data they don’t own through the interface that a service provides.
• Microservices themselves, not the messaging mechanism that connects them nor another piece of software, are responsible for “choreography” and collaboration — the sequencing of messages and actions to perform some useful activity.
• Each microservice can be deployed independently. Without this, a microservice application would still be monolithic at the point of deployment.
• A microservice is replaceable. Having a single capability places a natural boundary on size; likewise, it makes the individual responsibility, or role, of a service easy to comprehend.

An exception to our design are the concepts (load balancer and Databus) that are introduced above, which are not accepted by all publications, however, the differences with SOA are more shades than key points. For instance, microservices are responsible for coordinating actions in a system while this can be external in SOA (complex orchestration can be externalized). Others say that Microservices design is driven by business and SOA design is driven by technique (technical layers…). This is an expert’s debate…

Read the entire story at: https://www.lusispayments.com/news/tango-v8-an-implementation-of-microservices-architecture#

Lusis Tango runs successfully on the HPE Nonstop.  Lusis Payments has several customers realizing huge performance advantages running Lusis Tango on the HPE Nonstop.  In addition, our systems are highly scalable and available which is imperative in the mission critical environment. Second, we are not realizing apps, projects or custom development. We are designing and developing software that has to be economically competitive. This means for instance, that all development must look like the others, be written in the same way, with the same style, as we can’t afford “specialist developer” for this work.  This is close to the CBSD model of development that I won’t expound upon here but to say it is fundamental in our development approach.

Philippe Preval, CEO Lusis Payments