Skip to main content

Microservices vs. APIs

It still surprises me just how many times I come across misconceptions around Micro Services and APIs.

Often hearing phrases like micro services are fine grained web services or API is themselves are equivalent to micro services. These all sort of show fundamental misconceptions under the covers.
So, I've written this just to really break that out and explain about what the key differences are in those two concepts.

What is an API?
An API, fundamentally Application Programming Interface, that is an interface. It's a way of making requests into a component. So it's the route that you go in to make those requests. In modern use that typically means a REST API, that's a call made using HTTP protocol using JSON data as the payload.

What are Micro Services?
So let's ensure we also have a clear crisp definition on what a micro service architecture really is. Micro-Services architecture is about breaking down large silo applications into smaller components.
That are more manageable fully decoupled pieces with the aim of gaining benefit in terms of greater agility, more dynamic scalability and more targeted forms of resilience. Really it's about the shape and the size of the component that's within the application itself.

So, Micro-Services architecture that is really about breaking things down into small components. it's really a micro component architecture. An API is/are the interfaces that could  be used to expose the functionality in those components but the two of separate concepts. They're not directly related. There's no particular reason to assume.

For example, we changed our design from a large application to that of a set of separate micro service components. It would change the number of APIs that the overall application exposes or indeed change their granularity. Those two things are completely independent of one another.
So, Micro Services are components that are used  to build up an application in a more agile framework. APIs are a way of exposing functionality of an application whether it's written as micro services or not. There's no one-to-one correlation between the two. We could easily have Micro Service exposing multiple APIs or just one or indeed none at all.

A micro service component could be working on asynchronous messages, picking messages and manipulating, enriching them and putting them somewhere else. There may be no API whatsoever. It's just a component of an application.

Micro services and APIs are related, but they are not the same. Micro service is a component. referring them as Micro-service components may improve clarity.


We've skimmed over some pretty deep concepts here. Micro Services architecture is non-trivial to understand, when you start comparing it with things came before it like service oriented architecture and trusting between them that can really get quite sensitive.
Hope this helps to understand the fundamentals!


Comments

Popular posts from this blog

Face to Face Interview for 5+ years experienced .Net Developers

Interviewer: Hi Loganathan, Good morning. How are you? Me: Great, How are you? Interviewer: I'm good. Can brief about yourself? Me: Well, I started my career with .Net framework 2.0 then worked on 3.5 and 4.0 frameworks as well. So, I can work on any frameworks. I've no chance to develop a desktop application. From the begining I'm working as a pure Web developer. Initially started with ASP.Net web applications development and moved to Silverlight applications. I've well experience in C#, SQL Server 2005/2008 and WCF. I used Microsoft Enterprise Library Application blocks and LINQ in my applications. I worked in both Waterfall model and Agile model environments. Currently working as a Senior Developer. My roles and responsibilities are developing controls in Silverlight, writing WCF methods and consuming them in our applications, writing new stored procedures or modifying, doing unit testing and code review. Interviewer: Great, Can you explain about your curren...

Large Volume of Dataset Transfer from WCF to Silverlight

Most of the times the developers, architects have the problem to retrieve large volume of data from WCF Service to Silverlight client applications. It’s a big head ache for developers. But it’s not up to that much problematic one. We can solve this problem by changing some property’s values in Web.config of WCF Service host, Silverlight application’s ServiceReference.clientconfig and Silverlight XAP hosted ASP.Net Applications. Here I’m going to explain the Web.config changes we need to retrieve large volume of data from WCF Service and also uploading large size of files to the Server. Last week, I was trying to figure out why my WCF service call always threw the generic NotFound exception when trying to retrieve large datasets. Even though, I set buffer limits to 2147483647 (int.MaxValue) in the Silverlight ServiceReferences.ClientConfig file and WCF Service configuration Section under web.config the problem was persisting. I tried so many things from Data Access Layer and UI....

Multiplication Table in SQL Server

Multiplication Table in SQL Server This query gives the multiplication table from 1 to 10. DECLARE @A INT,                   @B INT,                   @C INT,                   @D VARCHAR (100)                   SELECT @A=1                  PRINT ' MULTIPLICATION TABLE 1-10' /****************************************/ /* Created By : Loganathan V */ /* Created On: 20-Sep-2010, Monday */ /* Purpose : Multiplication Table */ /* How to : RUN THE QUERY */ /****************************************/ WHILE (@A<=10) BEGIN   ...

Unity vs MEF in Prism

Prism offering two injection containers named Unity and MEF. Both the containers have their own capabilities. Before choosing the container decide your environment needs. Some of the capabilities provided by both ( Unity & MEF ) containers include the following: Both register types with the container. Both register instances with the container. Both imperatively create instances of registered types. Both inject instances of registered types into constructors. Both inject instances of registered types into properties. Both have declarative attributes for marking types and dependencies that need to be managed. Both resolve dependencies in an object graph. Unity provides several capabilities that MEF does not: Unity resolves concrete types without registration. Unity resolves open generics. Unity uses interception to capture calls to objects and add additional functionality to the target object. MEF provides several capabilities that Unity does not:...

One or more ActiveX controls could not be displayed because..... in Outlook

Some times We've facing this problem in Microsoft Outlook. While trying to add the images to our mails or Opening some emails. 1) Your current security settings prohibit running ActiveX controls on this page, or 2) You have blocked a publisher of one of the controls As a result, the page may not display correctly. To resolve this problem follow these steps. In Microsoft Outlook : Go to Tools > Options > Mail Format > Message Format Check the options " Use MS Office Word to ....". Happy Mailing..........................