Modular Architectures using Micro Services

Modular Architectures using Micro Services

About Me

Director at Luminis Technologies Member at the Apache Software Foundation

@m4rr5

Marcel Offermans

Agenda• Modular Architectures

• Micro Services

• OSGi in 60 seconds

• Amdatu

• Demo

Modular Architectures

The case for modularity

Maintainability

Adaptability

Quest for Reuse

Copy / Paste

Object OrientedQuest for Reuse

Component Based

Quest for Reuse

Micro Services

The term "Microservice Architecture" has sprung up over the last few years to describe a particular way

of designing software applications as suites of independently deployable services. While there is no precise definition of this architectural style, there are certain common characteristics around organization around business capability, automated deployment,

intelligence in the endpoints, and decentralized control of languages and data.

Source: http://martinfowler.com/articles/microservices.html

http://martinfowler.com/articles/microservices.html

Business Capabilities

• Should be leading when splitting an application into components

• Different from more traditional technology driven “layering” (UI, application logic, database)

Conway’s Law: Any organization that designs a system will produce a design whose structure is a

copy of the organization's communication structure. !

Melvyn Conway, 1967

Component owns Data• Each service manages its own data

• Can lead to polyglot persistence

• Leverage Domain-Driven Design: bounded context often maps naturally to components

• Use transaction-less coordination between services: build for eventual consistency and have a reversal process to deal with mistakes

Products

• Make the team responsible for the whole life cycle of a product or component

• Brings developers closer to the customers

Amazon:”You build it, you run it!”

Services• Provide a public, versioned contract for a

component

• Have their own life cycle, so they can be separately deployed

• Hide all implementation details

Dumb Pipes

• HTTP request/response

• lightweight messaging

Decentralized• Services decouple and abstract away components,

leaving us free to choose implementation languages

• Less focus on formal standards, more on proven, open source technology

Automated Deployment

• Continuous Integration

• Continuous Deployment

Design for Change• How to break a system into components? Consider

rate of change, high cohesion, low coupling, …

• Version your services, and make them tolerant to change

• Stay flexible!The only constant is change.

Design for Failure• Applications need to be able to deal with failures

• Services can always fail or become unavailable

• Monitoring is an important aspect

Netflix: Chaos Monkey to introduce random instance failures

Michael Jordan: I’ve missed more than 9000 shots in my career. I’ve lost almost 300 games. 26 times, I’ve

been trusted to take the game winning shot and missed. I’ve failed over and over and over again in

my life. And that is why I succeed.

OSGi in 60 seconds

What is OSGi?• Provides components that can be easily deployed

and versioned

• Hides implementation details and leverages a service registry that allows components to publish and consume services

• It’s the de-facto module system for Java: proven technology, works on all Java versions, usable from embedded to enterprise

META-INF/MANIFEST.MFstore/Store.classstore/Key.classstore/fs/StoreImpl.classstore/fs/FileSystem.classstore/fs/StreamUtil.classstore/fs/osgi/Activator.classlib/fsutil.jar

META-INF/MANIFEST.MF Bundle-SymbolicName: store.fsBundle-Version: 1.0.2

Bundle-Classpath: ., lib/fsutil.jar

Bundle-Activator: store.fs.osgi.Activator

Export-Package: store;version="2.5"Import-Package: org.foo.log;version="[1, 2)"

OSGi

META-INF/MANIFEST.MFstore/Store.classstore/Key.classstore/fs/StoreImpl.classstore/fs/FileSystem.classstore/fs/StreamUtil.classstore/fs/osgi/Activator.classlib/fsutil.jarstore/fs/osgi/Activator.class





class Activator implements BundleActivator { ServiceRegistration sr; public void start(BundleContext bc) { sr = bc.registerService(Store.class.getName(), new StoreImpl(), null); } public void stop(BundleContext bc) { sr.unregister(); }}


OSGi

META-INF/MANIFEST.MFstore/Store.classstore/Key.classstore/fs/StoreImpl.classstore/fs/FileSystem.classstore/fs/StreamUtil.classstore/fs/osgi/Activator.classlib/fsutil.jarstore/fs/osgi/Activator.class







OSGi


store/Store.classstore/Key.class

store/fs/osgi/Activator.class






Export-Package: store;version="2.5"

store;version="2.5"resolver

bundles


OSGi









Export-Package: store;version="2.5"Import-Package: org.foo.log;version="[1,2)"

META-INF/MANIFEST.MForg/foo/log/Log.classorg/foo/log/syslog/SysLogImpl.classorg/foo/log/syslog/Activator.class

store;version="2.5"

org.foo.log;version="1.3"resolver

bundles


OSGi









Export-Package: store;version="2.5"Import-Package: org.foo.log;version="[1,2)"

META-INF/MANIFEST.MForg/foo/log/Log.classorg/foo/log/syslog/SysLogImpl.classorg/foo/log/syslog/Activator.class

store;version="2.5"

org.foo.log;version="1.3"resolver

service registry

bundles

sr = bc.registerService(Store.class.getName(), new StoreImpl(), null);

store.Store { service.id = 1 }


OSGi

Remoting

java virtual machine

OSGi framework

bund

le

bund

le

bund

le

service registry


OSGi framework

bund

le

bund

le

service registry


OSGi framework

bund

le

bund

le

bund

le

service registry

bund

le

Amdatu

What is Amdatu?Amdatu is an open source community effort focussed on

bringing OSGi to the cloud. It contains components to create RESTful, scalable and distributed web applications that use

NoSQL data stores, transparent multi-tenancy and much more.

Development Model• Modular design based on OSGi

• Fast deployment using Bndtools

• Git fork/merge based workflow

• Extensive Atlassian tool support

• Apache ACE integrated with build servers

• Gradle based build

Demo

Wrapping Up

We’ve…• …explored modularity and micro services

• …introduced OSGi and Amdatu

• …seen how to develop and run a modular application

• …seen how OSGi allows you to be flexible in how you group and deploy components

Eclipse OSGi plugin!http://bndtools.org/ !

Provisioning Server!http://ace.apache.org/!

That’s us!http://luminis-technologies.com/

Demo code!https://bitbucket.org/marrs/javaone-2014-microservices/

Cloud OSGi services!http://www.amdatu.org/

TakkGrazie

Thank!you

Obrigado

MahaloDankeDank U

Merci

Gracias