Carbon 5 (C5) is the base of the next generation of WSO2 middlewere platform. 10 years back WSO2 re-achitected the middleware platform, which allowed us to develop comprehensive middleware functionality. Though the 10-year old Carbon kernel enabled WSO2 to build enterprise-grade middleware products, it’s now almost outdated. Generic server concepts, APIs and implementations from Apache Axis2 are now obsolete. Also In-JVM multitenancy is not the optimal solution in today’s container focused world. In this session, Sameera will talk about Carbon 5 – a complete redesign of the existing Carbon kernel. Carbon 5 provides a composable server architecture for you to build enterprise-grade servers. Based on OSGi, Carbon 5 allows you to develop componentized/modular servers. Pluggable runtimes, Artifact Deployment engine, Transport framework, light-weight repository and clustering framework are some of the features of Carbon 5.

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