A look at the searches related to the term “microservices” on Google Trends revealed that the top searches are now technology driven. This implies that the time of general search terms such as “What is microservices?” has now long passed. Not only are software vendors (for example, IBM and Microsoft) using microservices and DevOps practices, but also content providers (for example, Netflix and the BBC) have adopted and are using them. I report on experiences and lessons learned during incremental migration and architectural refactoring of a commercial mobile back end as a service to microservices architecture. I explain how we adopted DevOps and how this facilitated a smooth migration towards Microservices architecture.

1. Microservices Architecture Enables DevOps:
Migration to a Cloud-Native Architecture
Armin Balalaie, Abbas Heydarnoori
Sharif University of Technology
Pooyan Jamshidi
Imperial College London

2. Trend (DevOps-Microservices)
A. Balalaie, A. Heydarnoori, P. Jamshidi, Microservices Architecture Enables
DevOps: Migration to a Cloud-Native Architecture, IEEE Software, will appear
in May/June 2016 special issue on Software Engineering for DevOps.
Please drop me an email for the pre-print.
2 IEEE SOFTWARE | PUBLISHED BY THE IEEE COMPUTER SOCIETY 0 7 4 0 - 7 4 5 9 / 1 6 / $ 3 3 . 0 0 © 2 0 1 6 I E E E
Microservices
Architecture
Enables DevOps
Migration to a Cloud-Native
Architecture
Armin Balalaie and Abbas Heydarnoori, Sharif University of
Technology
Pooyan Jamshidi, Imperial College London
// This article reports on experiences and lessons learned
during incremental migration and architectural refactoring of
a commercial mobile back end as a service to microservices
architecture. It explains how the researchers adopted
DevOps and how this facilitated a smooth migration. //
A LOOK AT the searches related to
the term “microservices” on Google
Trends revealed that the top searches
are now technology driven. This im-
plies that the time of general search
terms such as “What is microser-
vices?” has now long passed. Not
only are software vendors (for ex-
ample, IBM and Microsoft) using
microservices and DevOps practices,
but also content providers (for exam-
ple, Netflix and the BBC) have ad-
opted and are using them.
In addition, Google Trends re-
veals that both DevOps and mi-
croservices are growing concepts,
with an equal rate of growth after
2014 (see Figure 1). Although Dev-
Ops can also be applied to mono-
lithic software systems, microservices
enable effective implementation of
DevOps by promoting the impor-
tance of small teams.1 (For more on
DevOps and Microservices, see the
related sidebar.)
A microservices architecture is a
cloud-native architecture that aims
to realize software systems as a
package of small services. Each ser-
vice is independently deployable on
a potentially different platform and
technological stack. It can run in
its own process while communicat-
ing through lightweight mechanisms
such as RESTful or RPC-based
APIs—for example, Finagle. (REST
stands for Representational State
Transfer.) In this setting, each ser-
vice is a business capability that can
utilize various programming lan-
guages and data stores and is devel-
oped by a small team.2
Migrating monolithic architec-
tures to microservices brings in
many benefits. In particular, it pro-
vides adaptability to technological
changes to avoid technology lock-in
and, more important, reduced time-
to-market and better development
team structuring around services.3
Here we explain our experiences
and lessons learned during incre-
mental migration of Backtory (www.
backtory.com), a commercial mo-
bile back end as a service (MBaaS),
to microservices in the context of
DevOps. Microservices help Back-
tory in various ways, especially in
shipping new features more fre-
quently and providing scalability for
the collective set of users from differ-
ent mobile-app developers.
Furthermore, we report on migra-
tion patterns we developed on the
basis of our observations in migra-
tion projects. Practitioners can use
these patterns to migrate monolithic
software systems to microservices. In
addition, system consultants can use
FOCUS: DEVOPS

3. Popular Search Terms on Google
building microservices
docker microservices
java microservices
microservice
microservices architecture
microservices example
microservices fowler
netflix microservices
soa microservices
spring microservices
agile devops
chef devops
cloud devops
devops aws
devops engineer
devops jobs
devops puppet
devops reactions
devops tools

4. Microservices
A cloud-native architecture

5. Developing a single application as a suite of
small services
Source: http://martinfowler.com/articles/microservices.html

6. There is a bare minimum of centralized
management of the services (Polyglot-ness)
Source: http://martinfowler.com/articles/microservices.html

7. SSaaS (Server Side as a Service)
A platform that makes mobile application development easier

8. Features of SSaaS
• Mobile application developers can use server-side capabilities
without knowing any server-side programming languages
• RDBMS as a Service
• Define data models in SSaaS dashboard
• Use the models’ objects in mobile application development
• Built-in user management
• Chat as a Service
• Integration with RDBMSaaS user authentication

9. Architecture of SSaaS before the migration

10. Reasons for migration
• On-demand capability of Chat as a Service
• The need for a reusable resource manager
• Management of resources like relational database instances, e.g. MySQL.
• The need for decentralized data governance
• Chat service’s metadata needed a dedicated place
• The need for automated deployment
• The need for built-in scalability

11. Target Architecture of SSaaS

12. Migration Steps
Incremental steps

13. Preparing the Continuous Integration Pipeline

14. Transforming DeveloperData to a Service

15. Introducing Continuous Delivery

16. Introducing Edge Server

17. Introducing Dynamic Service Collaboration

18. Introducing Resource Manager

19. Introducing ChatServices and DeveloperInfoServices

20. Clusterization

21. Monitoring

22. Delivery Pipeline

23. Team Formation

24. Lessons Learned
Experiences in migrating to microservices

25. Deployment in the development
environment is difficult for a
typical developer

26. Service contracts are double
important

27. Distributed system development
needs skilled developers

28. Creating service development
templates is important

29. The research on Microservices has started only in 2015,
Plenty of opportunities ahead!
1. Kratzke, N.: About microservices, containers and their underestimated impact on network
performance, CLOUD (March 2015).
2. Levcovitz, A., Terra, R., Valente, M.T.: Towards a technique for extracting microservices from
monolithic enterprise systems,VEM (September 2015).
3. Rahman, M., Gao, J.: A reusable automated acceptance testing architecture for microservices in
behavior-driven development,SOSE (March 2015).
4. Stubbs, J., Moreira, W., Dooley, R.: Distributed systems of microservices using docker and
serfnode, IWSG (June 2015).
5. Viennot, N., L´ ecuyer, M., Bell, J., Geambasu, R., Nieh, J.: Synapse: A microservices architecture
for heterogeneous-database web applications, EuroSys (April 2015).
6. Knoche, H., Sustaining Runtime Performance while Incrementally Modernizing Transactional
Monolithic Software towards Microservices, ICPE (2016).
More details? http://arxiv.org/abs/1507.08217

30. Migration Transition Graph

31. Cloud Migration through Pattern Composition
• The migration patterns can be seen as a sequence of activities by which
an application is gradually migrated to the micro-services.
• The migration patterns can be composed (i.e., executed sequentially) to
move a monolithic application to micro-services.

32. Migration Pattern Selection
Objective MP1 MP2 MP3 MP4 MP5 MP6 MP7 MP8 MP9 MP10 MP11 MP12 MP13 MP14 MP15
Time to market -- -- -- -- --
New capabilities -- -- -- --
Reduce operational cost -- -- -- -- -- --
Leverage investments -- -- --
Free up on-premise resources
Scalability -- -- -- -- -- -- --
Operational efficiency -- -- -- -- -- -- -- --
Re-host
Cloudification
Relocation
Refactor
Rebinding
Replacement
Modernization

33. Assembly-based Situational Migration
Objective MP1 MP2 MP3 MP4 MP5 MP6 MP7 MP8 MP9 MP10 MP11 MP12 MP13 MP14 MP15
Time to market -- -- -- -- --
New capabilities -- -- -- -- --
Reduce operational cost -- -- -- -- -- -- --
Leverage investments -- -- -- -- -- --
Free up on premise resources
Scalability -- -- -- -- -- -- --
Operational efficiency -- -- -- -- -- -- -- --

34. Assembly-based Migration Plan Construction
Objective MP1 MP2 MP3 MP4 MP5 MP6 MP7 MP8 MP9 MP10 MP11 MP12 MP13 MP14 MP15
Time to market -- -- -- -- --
New capabilities -- -- -- -- --
Reduce operational cost -- -- -- -- -- -- --
Leverage investments -- -- -- -- -- --
Free up on premise resources
Scalability -- -- -- -- -- -- --
Operational efficiency -- -- -- -- -- -- -- --

35. Migration Pattern Meta-Model

36. Migration Patterns in the context of Cloud-RMM
P. Jamshidi, A. Ahmad, C. Pahl, "Cloud Migration Research: A Systematic Review", IEEE Transactions on Cloud
Computing, 2013, DOI:10.1109/TCC.2013.10.
Migration patterns
Primarily facilitate
planning
Enable Auto-Deployment of
Multi-Tier Systems
in Hybrid Cloud Environment

37. Developing asingle application asasuite of
small services
Source: http://martinfowler.com/articles/microservices.html
Architecture of SSaaSbefore the migration
Target Architecture of SSaaS
Clusterization
Servicesare built around businesscapabilities
Source: http://martinfowler.com/articles/microservices.html
Servicesare independently deployable by
fully automated deployment machinery
Source: http://martinfowler.com/articles/microservices.html
There isabare minimum of centralized
management of the services(Polyglot-ness)
Source: http://martinfowler.com/articles/microservices.html
Transforming DeveloperData to aService Introducing ContinuousDelivery
Introducing Edge Server Introducing Dynamic Service Collaboration Introducing Resource Manager
Deployment in the development
environment isdifficult for a
typical developer
Service contractsare double
important
Distributedsystemdevelopment
needsskilleddevelopers
Creatingservicedevelopment
templatesisimportant