Microservices and API Management

Microservices

Agenda1. Microservices

I. Need for Microservices

II. Definition

III. Function & Features

IV. Microservices vs SOA

V. Areas of caution

2. API management

I. API and how its used ?

II. API management function & features

III. Examples

Need for Microservices In Monolithic Architecture the large monolithic code base intimidates developers,

especially ones who are new to the team. The application can be difficult to

understand and modify. As a result, development typically slows down

There are not hard module boundaries, modularity breaks down over time, to

implement a change or to deploy new versions of services frequently is difficult and

the quality of the code declines over time

Overloaded IDE - the larger the code base the slower the IDE and the less productive

developers are

Requires a long-term commitment to a technology stack

Fault isolation was required. one misbehaving component of a monolithic architecture

can bring down the entire system

Definition Microservices is a software architecture style in which complex applications are

composed of small, independent processes communicating with each other using

language-agnostic APIs.

These services are small, highly decoupled and focus on doing a small

task, facilitating a modular approach to system-building.

These services are built around business capabilities and independently deployable

by fully automated deployment machinery.

Microservices Architect the application by functionally decomposing it into a set of collaborating

services. Each service implements a set of narrowly, related functions.

Services communicate using either synchronous protocols such as HTTP/REST or

asynchronous protocols such as AMQP.

Services are developed and deployed independently of one another.

Each service has its own database in order to be decoupled from other services. When

necessary, consistency is between databases is maintained using either database

replication mechanisms or application-level events.

Microservices

The services are easy to replace

Services are organized around capabilities, e.g. user interface front-end,

recommendation, logistics, billing, etc.

Services can be implemented using different programming languages, databases,

hardware and software environment, depending on what fits best

Architectures are symmetrical rather than hierarchical (producer - consumer)

Microservices Features

Microservices vs SOA Microservices must be independently deployable, whereas SOA services are often

implemented in deployment monoliths.

Classic SOA is more platform driven, so microservices offer more choices in all

dimensions

Services in micro-service systems are smaller than most of those in SOA designs,

but most importantly micro services are stand-alone and are a manifestation of

the Single responsibility principle.

A service in SOA may have many responsibilities and thus may be as hard to evolve

as any monolithic application.

SOA initially started with XML/WSDL, but microservice architecture uses REST api.

Microservices vs SOA

Microservices vs SOA

Areas of Caution Developers must deal with the additional complexity of creating a distributed

system.

Testing is more difficult

Deployment complexity for different service types.

Increased memory consumption.

The tangled dependencies might make it difficult to decompose your monolithic

application into a set of services.

API Management

API Application programming interface (API) is a set of routines, protocols, and tools

for building software applications. An API expresses a software component in

terms of its operations, inputs, outputs, and underlying types.

API A good API makes it easier to develop a program by providing all the building

blocks. A programmer then puts the blocks together.

APIs do all this by "exposing" some of a program's internal functions to the outside

world in a limited fashion.

An API specification can take many forms, including an International Standard, such

as POSIX, vendor documentation, such as the Microsoft Windows API, or

the libraries of a programming language, e.g., the Standard Template Library in C+

+ or the Java APIs.

How API is used? API in procedural languages: API specifies a set of functions or routines that

accomplish a specific task or are allowed to interact with a specific software

component

API in object-oriented languages: is a description of how objects work in a given

object-oriented language expressed as a set of classes with an associated list of class

methods

API libraries and frameworks: An API can also be related to a software framework a

framework can be based on several libraries implementing several APIs

API and protocols: When an API implements a protocol it can be based on proxy

methods for remote invocations that underneath rely on the communication

protocol

The role of the API can be exactly to hide the detail of the transport protocol

API Management API management is a system in which an enterprise publishes application

programming interfaces (APIs) in a secure environment. The enterprise maintains

the APIs in a registry and exposes them to consumers inside or outside the

enterprise.

API Management FunctionsAPI management software tools typically provide the following functions:

Automate and control connections between an API and the applications

that use it

Ensure consistency between multiple API implementations and versions

Monitor traffic from individual apps

Provide memory management and caching mechanisms to improve

application performance

Protect the API from misuse by wrapping it in security procedures and

policies

API Management Features Documentation – Sounds boring, right? Still, one of the most common problems of

developers is figuring out how an API works. An API management service has to provide

an easy way to read the documentation and enable developers to “try before they buy”.

Analytics and Statistics – It is critical to understand how people use your API and get

insights for your business.

Deployment – Should be flexible and support public or private clouds, on-premises

implementations, or combinations.

Developer engagement – Engaging with your API consumers, developer or partners is

important. Getting an easily accessible developer portal will significantly facilitate

onboarding.

API Management Features Sandbox environment – This feature will increase both the value of an API and

its adoption rate. What better than being able to develop and test your code.

Traffic management and caching abilities.

Security – APIs carry sensitive data, so it is important to protect the exposed

information. The service has to at least provide identity and access

management for users and developers.

Monetization – Provide the capability to monetize your API.

Availability – Should be available, scalable and redundant. An API environment

can become demanding and the service should be able to deal with any kind of

errors, problems or temporary traffic spikes.

Support of Legacy systems.

API Examples The developer of a game app, for instance, can use the Dropbox API to let users

store their saved games in the Dropbox cloud

Sign In into many apps and Web sites using their Facebook ID—a feature that

relies upon Facebook APIs

Companies can shut down services and APIs that your applications depend on—or

they can go out of business entirely like Google regularly shuts down when it

doesn't see any profit in them—like Google Health or more recently, Google

Reader.