Polling-based APIs or the RESTful APIs were the main building blocks of traditional integration stories. But with the need to respond to events in real-time, integration architecture has shifted from being polling-based to event-driven. With the emergence of reactive event-driven architecture, the asynchronous APIs were able to hold their distinct position in modern-day integrations. Even though the event-driven APIs provide their own advantages such as high resiliency, high responsiveness, and more, management of asynchronous APIs continues to be a challenge to the organizations. The AsyncAPI specification plays a major role in the event-driven world by providing a specification to describe and document the asynchronous APIs. These slides will explore the entire flow from creating an asynchronous API to exposing it as a managed API by adhering to the AsyncAPI specification.

1. Managing Asynchronous APIs
October, 2021

2. Hello!
Lasantha Samarakoon
Associate Technical Lead @ WSO2
lasanthas@wso2.com

3. Event-Driven Architecture (EDA)

4. Why Event-Driven Architecture?
● RESTful APIs are the mainstay
● But not a quite fit for modern microservices based applications
● So the solution is the Event-Driven Architecture (EDA)
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5. What is EDA?
● EDA uses events to trigger and communicate among decoupled services.
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6. What is EDA?
● Main components of EDA:
⦿ Event Producer
⦿ Event Router
⦿ Event Consumer
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7. Benefits of EDA
● Help dealing with Microservice based architecture
● Scale independently. Fail independently.
● Easier to audit
● Easier to develop
● Cut costs
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8. Applications of EDA
● Data replication
● Enable parallel processing
● Monitoring and alerting
● System integration
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9. AsyncAPI

10. AsyncAPI
“A project used to describe and document, message driven APIs in both human and
machine readable format.”
● Protocol agnostic
● Opensource
● Now the AsyncAPI 2.0
● Either JSON or YAML supported
● The specification can be found at:
https://www.asyncapi.com/docs/specifications/v2.0.0
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11. AsyncAPI
Some of the main parts of the AsyncAPI specification are:
● Server
● Channel
● Operation
● Message
● Etc.
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12. OpenAPI vs. AsyncAPI
OpenAPI:
● Only support HTTP protocol
AsyncAPI:
● Many protocols/bindings available, such as HTTP, MQTT, AMQP, Kafka, JMS,
etc.
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OpenAPI AsyncAPI
Single client connecting to a single server Information is frequently shared with many consumers
at the same time
The client request information from the server No requests, instead the server proactively send
notifications
Only support HTTP protocol Many protocols/bindings available, such as HTTP,
MQTT, AMQP, Kafka, JMS, etc.

13. How to define an AsyncAPI?
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14. Manage an AsyncAPI
● As the AsyncAPIs are getting popular and being a major part of the integration
world, one the challenge is managing these APIs.
● It includes,
⦿ Enforcing security
⦿ Rate limiting
⦿ Monetization
⦿ Etc.
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15. Demo

16. It’s a Pizza Store…
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17. It’s a Pizza Store…
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18. It’s a Pizza Store…
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19. The Solution
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20. The Solution
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21. The Solution
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22. The Solution
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{
"event": {
"orderId": 1,
"status": "pending"
}
}

23. The Solution
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The docker-compose of this demo can be found at:
https://github.com/lasanthaS/wso2-asyncapi-demo

24. Question Time!

25. wso2.com
Thanks!