I know that Martin is enjoing the article on Microservices now.
I believe this requires a VERY accurate thinking. The first question to answer is whether Microservice has any relation to SOA Services.
It is not the first time when IT developers and Mr Fowler try to screw SOA - first time it was with Web Services, then, with DDD, now - with Microservices. I believe that IT developers do this subcontiously becuase they want to be associated with a 'cool stuff', their role in SOA is #16 - architects took everything from developers.
I commented on this articel some time ago in the Yahoo SOA User Group. I also contacts Anne Thompson - the SOA lead of Catalist, one of the most known and respectful thinker in SOA world, not a VP in Gartner - regarding her presentation and article on Microservices. I know her for 7-8 years already and see how she stands upside-down in order to talk about Microservices in the most natural manner rather than simply say that theyare not SOA services and do not compliant with the Principles of Service-Orientation (PoSO).
Microservices as much services as Web Services and REST. Moreover, thier compositions form not a service (as ANY composition of real service would do, but an application, which ignores PoSO. An idea of creating an application from idependent elements at the enterprise and cross-enterprise level is as new as EJB. The only difference here between eJB and Microservices is the same as between CORBA Service and Web Services - a communication protocol and related constraints.
I have noticed that Microservices play exactly the same game with managers and decision-makers - they hear word 'services' and believe it is about services. Well, it is impractical to try to convince them in the wrong thinking until they fail with thier projects (becuase taking Microservies as services and promissing business values that do not present there).
Here is a very simple example: your company is in a serious finiancial business that depends on the behaviour of the stocke in the exchnages; your developer loves APIs and Microservices accessible via APIs; the developer uses Microservice that promis to return certain dynamics of the stocks in the Exchange A. Everything is fine, you are in business. The disaster (in business sence) happens to you when you find that either the dynamics of the stocks either does not come on time and you setup several trades on your business clients or dynamics of the stocks has come from another Exhange becuase that Microservices provider decided temporary to switch the source of its data. It is not a problem to him - he has no obligations to you.
Another example, you are working in a regulated market, you use a Microservice that operates in your locale and you suggest it is compliant with the Governmnet regulations. However, the regulation does not apply to the Microservice and it, in turn, utilises another Microservice that operates under the rules that contradict your local regulation. You are in fault, but the Microservice does not care, it is a stupid brainless API and it is 'micro' - get off its back!
Sent: Saturday, September 12, 2015 at 4:39 PM
From: "Ken Laskey" <firstname.lastname@example.org>
To: "Martin Smith" <email@example.com>
Cc: "firstname.lastname@example.org" <email@example.com>
Subject: Re: [soa-rm] Microservices
I did some reading earlier this year and I see to remember a Martin Fowler post — I think, http://martinfowler.com/articles/microservices.html
. The Open Group has had a committee discussing this. I had intended to follow more closely but haven’t.
We can discuss on Wednesday.
Dr. Kenneth Laskey
MITRE Corporation, M/S F510 phone: 703-983-7934
7515 Colshire Drive fax: 703-983-1379
McLean VA 22102-7508
Sad to say, I hadn't noticed this term (apparently originated in 2005!) until recently.
Fits under the heading of "pros and cons of service granularity", I guess.
Martin F Smith, Principal
BFC Consulting, LLC
McLean, Va 22102
703 389-3224 mobile