Modularity in the cloud

A case study

Jan Willem JanssenLuminis Technologies

@j_w_janssen

Sander MakLuminis Technologies

@sander_mak

http://branchandbound.net

The case: PulseOn

Educational system focussed on personalized learning

Used in high schools in the Netherlands

Expand to other countries in the near future

Requirements

Easy software

updates

Cross deviceiPad/android/

desktop...

Different set of components per

school

Scalability(both up and

down)

Personal dashboard

Learningcontent

Adaptive recommended

Learning

How to build software

when nobody can tell you

exactly what to build?

Divide and conquer, prevent the ripple effect

Modularity

Modularity in practice

Program to interfaces, not

implementations

Rate of change

of modules

http://geekandpoke.typepad.com

Modules

Ok, but how to create an instance of a hidden

class?

MyInterface myI = new MyImplementation();

YOUDON’T!

Service Lookups

Cross device HTML 5 + JS

RESTful web services

OSGi services

Mongo

Apache Felix

Amdatu

S3

course.gadget

contentsequencer.rest

content.mongo content.storage

Mongo S3

UI

REST API

JavaAPI

course.gadget

contentsequencer.rest

contentsequencer.engine profiling.mongo

content.mongo

profiling.rest

AJAX AJAX

Java Java

Java

Java

Some numbers

190bundles

in a deployment

120PulseOn

bundles

Amdatu: OSGi Cloud components

JAX-RSMongo DBBlobStoresSchedulingMulti-tenancySearchOpenSocial...

Apache Licensed

open source

project

Amdatu MongoDB

Most data is

exposed using

REST

The profiler generates a LOT

of data

The recommender

needs powerful queries

Amdatu OpenSocial

How to separate UI elements in modules?

Each functional part is an

OpenSocial gadget

Modularity in the UI

School B

Load

Deployment

Load Balancer

PulseOn nodePulseOn node

PulseOn node

Load Balancer

PulseOn nodePulseOn node

PulseOn node

School A

MongoMongo

Mongo

MongoMongo

Mongo

Auto scaling

Considerable higher loads during school hours

Enoughcapacity

Without paying for idle servers

at night...

Load Balancer small node

Cluster per school

Always use a load balancer because we don’t want downtime during scaling

Load Balancer small node

Early morning...

Load Balancer small node

large node

large node

Early morning...

End of the day...

Load Balancer small node

large node

large node

End of the day...

Load Balancer small node

But how do we install

our software on a node?

Provisioning servers

ace screenshot

Node

AWS Auto Scaling

1. Start Load Balancer

Apache ACE

4. register

2. register

3. provisiondeployment

package

Provisioning servers

Tooling and frameworks are

now mature enough

How does this fit other applications?

The architecture fits most

modern web applications

Works in the cloud

(but not a requirement)

amdatu.org

Cloud provisioning

http://ace.apache.org/Cloud OSGi services

http://www.amdatu.org/

Eclipse OSGi pluginhttp://bndtools.org/

@Sander_Mak

http://luminis.eu/en/

There is more...