Building Modular Cloud Applications in Java - Lessons Learned
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The document discusses the experience of building modular cloud applications in Java, particularly for the Pulseon educational system in the Netherlands. It highlights the importance of modularity for agility, outlines architectural principles, and explores deployment challenges and solutions. Additionally, it emphasizes tools and frameworks such as OSGi and AMDATU, while advocating for personal development in cloud-based applications.
Building Modular Cloud Applications in Java - Lessons Learned
- 1. Building Modular Cloud Applications in Java Lessons Learned
- 2. Bert Ertman Fellow at Luminis in the Netherlands JUG Leader for NLJUG and a Java Champion Paul Bakker Architect at Luminis Technologies @BertErtman @pbakker a presentation for
- 3. The case PulseOn Educational system focussed on personalized learning Used in high schools in the Netherlands Expand to other countries in the near future
- 4. Re: Cloud Applications Some characteristics: Application as a service over the internet Impact on some non-trivial non-functionals Availability Scalability Extensibility
- 5. Observations Extremely agile Architecture (and code base) should be able to cope with change
- 6. The case for modularity Modularity is the ultimate agile tool! Small, disposable, components Prevents code rot on the architectural level Isolate problems, focus work
- 7. Prevent (tight) coupling What we learned about OO design in university : Promote cohesion coupling cohesion
- 8. Whatdoweneed? design consequences High-level enterprise APIs Architectural focus on modularity Runtime dynamic module framework Right now, OSGi is the only option let’s not reinvent the wheel
- 9. OSGi is the de-facto standard module system for Java OSGi != modularity What about Jigsaw?
- 10. OSGi is the de-facto standard module system for Java OSGi != modularity What about Jigsaw? remember! Modularity is an architectural principle
- 11. OSGi is the de-facto standard module system for Java OSGi != modularity What about Jigsaw? remember! Modularity is an architectural principle Modularity does not come for free with a framework
- 12. demo
- 13. Profiles Rest Profiles API Profiles Service MongoDB Progress Rest Progress API Progress Service MongoDB Curriculum API Curriculum Service MongoDB ... Rest ... API ... Service modularity in action...
- 14. Back to the cloud...
- 15. HTML 5 + JavaScript RESTful services OSGi services Mongo Apache Felix S3 Typical architectureRequirements: Modern web app UI mostly offloaded to clients or devices Document driven interaction Integration via REST API Web scale data store Multi-tenant Elasticity
- 16. HTML 5 + JavaScript RESTful services OSGi services Mongo Apache Felix A m d a t u S3 Typical architecture Let’s Add AMDATU to our stack Architectural focus on modularity Runtime dynamic services High level API
- 19. PaaS Offerings out there: Not good: Proprietary platform Vendor lock-in White list / black list OS Limitations No support for modular runtime
- 20. Solution: roll our own PaaS Modular PaaS: IaaS image OSGi runtime Deployment/provisioning PaaS Building blocks Pro: freedom Con: no vendor support Amazon EC2 Apache Felix Apache ACE Amdatu
- 21. Deployment Load Load Balancer PulseOn node PulseOn node PulseOn node School A Mongo Mongo Mongo Load Load Balancer PulseOn node PulseOn node PulseOn node School B Mongo Mongo Mongo
- 23. Horizontal scaling requires stateless nodes HTML5 clients need less server side state Any state should go to some kind of store Horizontal scalability
- 24. Auto scaling Considerable higher loads during school hours Enough capacity Without paying for idle servers at night...
- 25. Load Balancer small node Cluster per school Always use a load balancer because we don’t want downtime during scaling
- 26. Early morning... Load Balancer small node
- 27. Early morning... Load Balancer small node large node large node
- 28. End of the day... Load Balancer small node large node large node
- 29. End of the day... Load Balancer small node
- 30. But how do we install our software on a node?
- 31. Some numbers 190 bundles in a deployment 120 PulseOn bundles
- 34. Provisioning servers Node AWS Auto Scaling 1. Start Load Balancer Apache ACE 2. register 3. register 4. provision deployment package
- 35. ./as-‐create-‐launch-‐config demo -‐-‐image-‐id ami-‐0ee8e07a -‐-‐instance-‐type m1.small -‐-‐region eu-‐west-‐1 -‐-‐group sg-‐ce1420ba -‐-‐user-‐data-‐file userdata.txt ./as-‐create-‐auto-‐scaling-‐group demo -‐-‐launch-‐configuration demo -‐-‐min-‐size 1 -‐-‐max-‐size 1 -‐-‐availability-‐zones eu-‐west-‐1a -‐-‐load-‐balancers demo -‐-‐tag "k=Name,v=demo,p=true"
- 36. Or by UI configuration...
- 37. Provisioning servers Nodes are completely disposable Automated cluster recovery Nodes do not require maintenance No “big” container
- 38. Developer Tools
- 39. Educational system focussed on personalized learning Used in high schools in the Netherlands Expand to other countries in the near future Development tool stack IDE with fast turn arounds Version Control Continuous Integration Server Issue tracker WIKI what do we need?
- 40. Continuous integration All BndTools projects support headless builds Build on git push Measure test coverage (both unit and integration tests)
- 41. Wrap up
- 42. what have we learned? Modularity is the ultimate agile tool Modularity is no longer difficult (BndTools / Amdatu) Stateless architecture is the only scalable way Cloud deployments made easy with a provisioning server
- 43. Shameless self-promotion... Our book Building Modular Cloud Applications in Java Published by O’Reilly Due: end of summer this year under construction
- 46. Want to try this yourself? Tomorrow: 10 AM - 12.30 Hands-on Lab: Building Modular Cloud Applications in Java Venue: Hotel Wyspiański ul.Westerplatte 15 31-033 Kraków
- 47. Cloud provisioning http://ace.apache.org/ Eclipse OSGi plugin http://bndtools.org/ That’s us http://luminis.eu/ Bert Ertman bert.ertman@luminis.eu @BertErtman Cloud OSGi services http://www.amdatu.org/ Amdatu Paul Bakker paul.bakker@luminis.eu @pbakker