Carbon 5 is the next generation of the WSO2 Carbon middleware platform. It has been re-architected using microservices and containers to improve modularity, scalability, and multi-tenancy. Key changes include moving from Apache Axis2 to a lightweight OSGi-based kernel, using Kubernetes for container orchestration instead of Stratos, and releasing initial products like the Microservices Server and Gateway built on this new kernel. The first general availability release of Carbon 5 and these products is planned for December 2015.

1. Carbon 5 : A Preview
Next-generation WSO2 Carbon Platform
Sameera Jayasoma
Software Architect
WSO2

2. Carbon 5 (C5)
• Next-generation WSO2 Carbon platform.
• Completely re-architected to keep up with the
technology changes.
• Light-weight Carbon kernel providing a componentized
server development framework.
• To provide a streamlined and even more powerful
middleware platform than ever.
• Supports multi-tenancy and autoscaling

3. Why C5?
• Carbon 4.x and previous versions enabled us to build an
enterprise-grade middleware platform with 20+
products to date.
• Started way back in 2008, Carbon revolutionized WSO2’
s middleware space.
But it’s time to make a change. why?

4. Why C5?...
• Common message model is SOAP Infoset
• XML is more native than JSON.
• Tight coupling with,
• e.g. Apache Axis2,
• Apache Synapse.
• Server building concepts are from Axis2. Removing these
couplings is not easy, hence require a Major release of
the Carbon platform and it will not be compatible with
previous releases.
• In-JVM multitenancy is not optimal for runtime isolation.

5. History of Carbon

6. Carbon Platform Releases
• Carbon Product = Subset of platform features + Carbon
kernel.
• All products belong to a single platform release are
compatible with each other.
• Platform releases are named after Turing award winners. e.g.
next carbon platform is called Hamming.

7. Carbon Platform
• OSGi and P2 gives modularity
and composability to the
platform.
• Carbon Kernel - base runtime.
• Set of core features for
middleware products.
• Middleware features
• Carbon products as packaged
collections of features

8. Carbon Kernel - 5.0.0
• Light-weight base runtime for the next generation WSO2
Carbon Platform.
• Modularity and composability are inherited from OSGi :
Dynamic module system for Java and Equinox P2 (Provisioning
platform for OSGi based applications)
• Carbon Kernel features
• Composable Server Architecture
• Transport Management
• OSGi Startup order resolver
• Artifact Deployment Engine
• Managed runtime model.

9. Carbon Kernel Architecture

10. Composable Server Architecture
Souce: https://en.wikipedia.org/wiki/Composability

11. Composable Server Architecture...
• Composable middleware system vs “Suite” of products.
• provides a consistent solution to cross-cutting functions,
usability, manageability etc.
• Benefits of adopting OSGi + P2 .
• Carbon Feature Plugin.
• To build features, products, products with multiple
profiles, mix-and-match components, etc.

12. Managed Transports
• Transports in a Carbon based product can be managed
centrally.
• Maintenance mode concept to handle upgrades.
• New transports can be plugged in easily.
• Implement the org.wso2.carbon.kernel.transports.CarbonTransports
interface and register it as an OSGi service at runtime.
• Start all the transports once all the transport services are
available and once the server is ready to serve requests.

13. Managed Transports...

14. Artifact Deployment Engine
• Manages the artifact deployment in Carbon
based products.
• Scheduler : Responsible for the scheduling the
deployment tasks periodically.
• Repository Scanner : Scans deployer directories
for artifact updates.
• DeployerServiceListener : An OSGi service
component, which listens to deployer
registrations/unregistrations from other
components (CustomDeployers) at run-time.
• Periodically checks the repository for changes
and invoke relevant deployers

15. Startup Order Resolver
• Startup order resolving mechanisms in OSGi.
• In Carbon, these standard mechanisms are not enough.
• Intra-component dependencies
• e.g. all transports need to be initialized only when all of
them are ready.
• Inter-component dependencies.
• e.g all transports should be started after all the deployers
are initialized.

16. Startup Order Resolver
• Provided-Capability vs Require-
Capability.
• Declaring the capabilities provided
by your bundles
a. Using the Provide-Capability OSGi
MANIFEST header
b. Implementing the
CapabilityProvider and providing
it as an OSGi service

17. Execution Multi-tenancy with
Containers
• Issues with in-container multi-tenancy (in-JVM)
• Isolation is very hard to achieve. One application can interfere
with another application in many ways.
• Even though in-container multi-tenancy claims to optimize
resource utilization with higher tenant density, it has many
other limitations.
• Container based multi-tenancy provides true isolation
compared to in-container multi-tenancy.

18. Docker and Kubernetes for Scalability and multi-
tenancy
• Not for static scale deployments without execution multi-
tenancy.
• C5 marries a PaaS framework for scalability and multi-tenancy
• Moving away from Apache Stratos to Kubernetes as default
PaaS framework
• K8S namespaces for multi-tenancy
• K8S elastic scaling (work in progress)

19. WSO2 Microservices Server 1.0.0
• A lightweight, high performance microservices runtime
• One of the first products to be released with Carbon kernel
5.0.0.
• Reusable lightweight micro service engine.
• Multiple modes: Standalone, Server mode
• Leverages Deployment engine, Transport framework and
startup order resolver from kernel.

20. WSO2 Gateway 1.0.0
• High-performance, lightweight, and configuration-driven
message gateway
• Another product to be released with Carbon kernel 5.0.0.
• Protocol handling layers and message processing layers are
fully decoupled
• Leverages the Transport framework in Kernel with support
from startup order resolver.
• Foundation for the upcoming series of WSO2 Gateway*
products. e.g. WSO2 API Gateway, WSO2 File Gateway, WSO2
Security Gateway etc.

21. WSO2 Application Server 6.0.0
• App Server architecture moving from “Carbon underneath” to
“Carbon as needed”
• Issues in migrating from Tomcat to WSO2 AS.
• Classloading complexities etc.
• WSO2 AS 6.0.0 = Apache Tomcat + Libraries to leverage WSO2
Platform features.
• Security, SSO, DAS integration, classloading
improvements etc.
• OSGified Tomcat will be available as a middleware feature for
webapp hosting within a Carbon 5.0.0 runtime

22. Carbon Kernel 5.0.0 - Release Plan
• We released alpha last week. Just before the con :)
• Download alpha version from https://github.
com/wso2/carbon-kernel/releases/tag/v5.0.0-alpha.
• Source code is available in https://github.com/wso2/carbon-
kernel/tree/5.0.x
• GA will be released in December 2015 with product-mss and
product-gw.

23. Thank You