WSO2 Gateway is a high performance message gateway that encapsulates messaging between disparate systems. It uses a fully decoupled architecture with the Carbon Message as the data carrier between protocol handling layers and the message processing engine. The gateway supports thousands of concurrent HTTP/S connections using Netty and Disruptor for high performance. It can route messages using Apache Camel and define REST APIs. Performance tests show it is around 10x faster than the existing WSO2 ESB and can handle more concurrent connections. The gateway is targeted for use in API gateways, load balancers and other integration patterns.

1. WSO2 Gateway
Kasun Indrasiri
Software Architect
WSO2

2. Outline
• Introduction to WSO2 Gateway
• Motivations/Objectives
• High level architecture and design
• Features
• Message flow
• Performance comparison.
• Use cases
• Conclusion.

3. Introduction to WSO2 Gateway
• WSO2 GW encapsulates the messaging between source and
target systems which are built with disparate technologies,
protocols and standards.

4. Motivations
• Paradigm shifts in Non-blocking IO, message/event processing,
concurrent programming - Netty, Disruptor, Java 8, Reactive
Programming.
• Research work - Siddhi CEP based ESB, axis2-Netty transport.
• Overcome the limitations of axis2, synapse etc.
• Reuse the prior knowledge and experience of building high
performance messaging systems to build a better message
Gateway from the ground up.
[1] https://github.com/kasun04/siddhi-esb

5. Objectives
• To build a high performance, lightweight and reusable message
Gateway based on Gateway Pattern[1]
• To be used as the foundation component of ESB, API GW, Load
Balancer, Security GW, File GW etc.
[1] http://martinfowler.com/eaaCatalog/gateway.html

6. WSO2 Gateway – Architecture
• Fully decoupled protocol handling layers from message processing layer.
• Carbon Message - Data carrier between protocol handling and message
processing layers, contains message attributes and reference to message
content, Message Consumers - protocol handling of inbound messages.
• Message Producers/Senders - protocol handling of outbound messages.
• Message Processing Engine - process/mediate the messages.

7. WSO2 Gateway 1.0 – Features
• Ultra high performance and low latency HTTP/S messaging.
• Supports thousands of concurrent connections/clients.
• Header-based routing using Apache Camel as the message mediation
engine.
• Defines REST services/APIs using Camel REST DSL
• Lightweight and stateless service orchestration.
• Load balancing and failover messaging.
• Error handling support.

8. WSO2 Gateway – Message Flow
• Message receiving, processing and sending are handled with the use of
Callbacks. (No notion of Inflow and Outflow.).
• Message consumer sets consumerCallback which is called by the Engine,
when the response message is ready to be sent to the client (i.e. when
mediation is completed.).
• Engine sets the engineCallback which gets called by Producers when the
response for a given request has arrived

9. WSO2 Gateway – HTTP Messaging
• WSO2 Gateway uses Netty based HTTP transport implemented on
message WSO2’s Pass-Thru (PT) architecture [1].
• Overcoming the consumer/producer contention in PT shared
buffer/pipe with a new blocking queue and ring buffer architecture
(Disruptor).
[1] http://wso2.com/library/articles/2013/12/demystifying-wso2-esb-pass-thru-transport-part-ii/

10. WSO2 Gateway – HTTP Transport
• Netty HTTP Transport - Using executors

11. WSO2 Gateway – HTTP Transport
• Netty HTTP Transport - Using Disruptor

12. WSO2 Gateway – Mediation Engine
• Using Apache Camel as the mediation engine.

13. WSO2 Gateway – Performance
• Performance comparison for fast backend.
• WSO2 GW - with Camel mediation for header based routing.
• WSO2 GW is nearly 10x faster than existing WSO2 ESB’s transport.

14. WSO2 Gateway – Performance
• Handling concurrency with slow backend (5s delay).
• NHTTP/BR failed at c=4k, PTT failed at c=8k, GW can go upto c=12k.
• We are further enhancing high concurrency support in GW

15. WSO2 Gateway – Performance
• Latency comparison

16. Use case I – Header-based Routing
• Camel configuration for Header-based routing.

17. Use case II – Using REST
• Defining REST services for existing web APIs.

18. Gateway in Microservices Architecture
• API Gateway is used in most real world microservice
implementations to front microservices.
– Eg Netflix API GW[1]
[1] Source : http://microservices.io/patterns/apigateway.html

19. Resources
• Download WSO2 GW 1.0.0-Alpha
• Source Code - https://github.com/wso2/product-gw
• Getting Started guide.
• Public Jira - https://wso2.org/jira/browse/WGW
• WSO2 GW – 1.0.0 GA is on early December.

20. Thank You