intro to osgi – the microservices kernel - p kriens & t ward

OSGi – The µServices KernelA high level technical introduction to OSGi

Once upon a time in 1998 …

long before SOA …

A JSR was born …

the OSGi Service FrameworkService

Service

To prevent confusion, we coined the term …

micro-service

they did it again …

µService

because we are worth it …

Let’s go back to the beginning

Modularity

• modules have a private space and share a public space

• modules limit their visibility and exposure

• complexity ∷ parts2

A B

C D

Modularity

• modules have a private space and share a public space

• modules limit their visibility and exposure

• complexity ∷ parts2

A B

C D

Pub

Softw

are

Com

plex

ity

Moving Parts

Modularity’s Secret

A v1.0

C v1.1

B v2.3

Interfaces/API

User Class

Implementer ClassInterface

User Class


Interfaces/API

package com.api package com.provider.implpackage com.consumer.impl

User Class


Interfaces/API


DocumentBuilderYour App Xerces

User Class


Interfaces/API


User Class


Interfaces/API


User Class


priva

te

Interfaces/API

Now what?


List

en


Regi

ster

List

en


Regi

ster

Get

List

en

An honest broker …

Overhead?

µService call ≡ Method call

µService ≡ object

Closer with less irritation …

.

REST

SOA

.

REST

SOA “MICRO Service”

.

REST

SOA “MICRO Service”

µservice

.

REST

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

G

B

E

H

C

F

I

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

B

E

H

C

F

I

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

F

I

B

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

F

I

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

D

A

G

E

H

C

F

I

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

D

A

G

E

H

C

FF

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

FF

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

FF

Ba Bb

D

A

G

E

H

C

F

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

FF

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

FF

I v2.0

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

FF

I v2.0

S;1.1.0

F

Ba Bb

OSGi• Adaptive

• Flexible

• Contracts

• Robust

• Secure

• Evolution

• Distributed

D

A

G

E

H

C

FF

I v2.0

S;1.1.0

F

REST

Service Patterns• Factory

• Listener

• Discovery

• Distribution

• Dependencies

But OSGi is so complicated!

Sigh …

Complexity is in the eye of the beholder

The right tool for the job …

meet bnd(tools)

bnd(tools)• DS Component Annotation support

• Access to maven central and more

• Based on Capability model

• Extensive debugging with dynamic updating

• Executable JARs

• Release tool with semantic versioning

• Baselining

• Integration with Continuous Integration

bnd(tools)• DS Component Annotation support

• Access to maven central and more

• Based on Capability model

• Extensive debugging with dynamic updating

• Executable JARs

• Release tool with semantic versioning

• Baselining

• Integration with Continuous Integration

See

Nei

l Bar

tlet

t’s

talk

on B

ndto

ols

nex

t

OSGi enRoute

cost

of c

hang

e

functionality

cost

of c

hang

e

functionality

dynamic languages

cost

of c

hang

e

functionality

dynamic languages Java/OSGi

cost

of c

hang

e

functionality

dynamic languages

Java/OSGi

In the end, OSGi is inevitable …

OSGi Release 6• June 2nd the OSGi Core Release 6 Specification received its final

approval and will be available this week to the public for downloading.

• http://www.osgi.org/Specifications/HomePage

• The OSGi Board of Directors also approved the publication of an Early Draft Specification of OSGi Enterprise Release 6 for downloading.

• http://www.osgi.org/Specifications/Drafts

OSGi Release 6• June 2nd the OSGi Core Release 6 Specification received its final

approval and will be available this week to the public for downloading.

• http://www.osgi.org/Specifications/HomePage

• The OSGi Board of Directors also approved the publication of an Early Draft Specification of OSGi Enterprise Release 6 for downloading.

• http://www.osgi.org/Specifications/Drafts

NEW

intro to osgi – the microservices kernel - p kriens & t ward

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