Content regarding the Lisbon Mulesoft Meetup

1. 17/02/2021
Lisbon MuleSoft Meetup Group
Async APIs: Event Driven Architecture

2. Introductions
●About the organizers:
○ Meetup Leader: Steve Fernandes
○ Meetup Speaker: João Batista
●Sponsors:
○ Timestamp:its
2

3. Agenda
● Event Driven Architecture (5 min.)
● Why Async API? (5 min.)
● Async API Specification (15-20 min.)
● Demo (10 min.)
● Q & A
● Quiz - MuleSoft Vouchers
3

4. Event Driven Architecture

5. Event Driven Architecture (EDA)
● Events
● Trigger – change in state
● Main Concepts
● Delivery Guarantee - ACK
5
Producer
Broker
Consumer

6. Event Driven Architecture - Benefits
1. Better Scalability & Fault tolerance
2. Versality & Agility
3. Cut costs
● Event driven architecture taken by the planet’s
most successful enterprises.
● Mid 2021Fortune 100 using EDA via Kafka.
6
80% IoT
Cloud Messaging

7. Event Driven Architecture - Challenges
7
Discovery Governance Visibility

8. Event Driven Architecture - Challenges
● Protocols?
● Event Structure?
● Broker configuration?
8
Discovery Governance Visibility

9. Event Driven Architecture - Challenges
● Security?
● Access management?
● Best Practices & Convention
9
Discovery Governance Visibility

10. Event Driven Architecture - Challenges
● Information?
● Taking insights
● Preventative actions
10
Discovery Governance Visibility

11. Why Async API?

12. Why Async API?
● Necessities on message based systems (EDA, IoT, etc) –
Open Source Specification!
● Purposely based & mapped from OpenAPI Spec;
● Supported by many industry leader event-driven players
12

13. Why Async API - MuleSoft
● Design Center – Build a Specification & sharing a standard across
MuleSoft world
● Anypoint Exchange – MarketPlace for synchronous & asynchronous
APIs
13

14. Async API Specification

15. Introduction
● Async API Specification (A2S): Describe and document message-
driven APIs, protocol-agnostic. Specification format: JSON/YAML.
● Async API Schema: aggregates in main sections broker resources listing,
and API declaration into one document
15

16. Walk through over Specification…
● AsyncAPI: current version (2.0.0)
● Id: Application identifier
● Info: metadata about the API. The metadata can be used by the clients
if needed;
● tags: Helpful in addressing specifications onto different categories;
● externalDocs: links specification as part of a broader application
16

17. Walk through over Specification…
● Provides connection details about host message broker
● Support protocol (NOT Limited):
17
Servers
Servers
(queue/topic/destination
name)
url (required!)
Protocol (required!)
protocolVersion
Description
variables
security
Bindings
amqp amqps
Kafka-secure
secure-mqtt
stomp stomps ws wss
mqtt
https
http

18. Walk through over Specification…
● Provides connection details about host message broker
○ Fixed upon following fields:
18
Servers
Servers[ ]
url (required!)
Protocol (required!)
protocolVersion
Description
variables
security
Bindings

19. Walk through over Specification…
● Provides connection details about host message broker
○ Security: security mechanisms applied on server, which stands out:
19
Servers
Servers[ ]
url (required!)
Protocol (required!)
protocolVersion
Description
variables
security
Bindings

20. Walk through over Specification…
● Provides connection details about host message broker
○ Security: security mechanisms applied on server to allow the operation,
which the following ones can be applied :
20
Servers
Servers[ ]
url (required!)
Protocol (required!)
protocolVersion
Description
variables
security
Bindings
User/Password
API Key
X.509 Certificate
OAuth2
OpenId Connect
Discovery
HTTP API Key
E2E Encryption
SASL
Security Schemes

21. Walk through over Specification…
21
Server Bindings
● Aims to help with more detail about the protocol and/or the topology.
Servers[ ]
url !
protocol !
description;
protocolVersion
variables
security
bindings

22. Walk through over Specification…
● Components: Reusable components across AsyncAPI
specification.
● Must be referenced by properties outside (servers, channels,
etc).
● References: linking other components internally or externally
spec.
○ $ref – JSON reference only used for JSON/YAML specs
formats
○ Add/Extend properties is not an option
22
Components & References

23. Walk through over Specification…
● Components: Reusable components across AsyncAPI
specification.
● Must be referenced by properties outside (servers, channels,
etc).
● References: linking other components internally or externally
spec.
○ $ref – JSON reference only used for JSON/YAML specs
formats
○ Add/Extend properties is not an option
23
Components & References

24. Walk through over Specification…
24
Bindings
● Aims to help with more detail about the protocol and/or the topology.
Servers
• mqtt
Channel
• ws, amqp
Operation
• http, amqp, kafka, amqp, mqtt, nats
Message
• http, kafka, amqp, mqtt

25. Walk through over Specification…
25
Server Bindings Examples
● Provides information needed to setup a server configuration according
protocol defined

26. Walk through over Specification…
26
Channel Bindings Examples
● Provides information needed to manage a channel specification
according protocol defined

27. Walk through over Specification…
27
Operation Bindings Examples
● Provides information needed to apply protocol priority configurations
on a publish/subscribe operations

28. Walk through over Specification…
28
Message Bindings Examples
● Provides information needed to apply protocol definitions over
messages

29. Walk through over Specification…
● Holds the relative paths to the individual channel and their operations.
Each channel documentation is enhanced by following features:
29
Channels
Channels
(queue/topic/d
estination
name)
Reference
structure ($ref)
description
Operation
(Subscribe
Publish)
Parameters
Bindings

30. Walk through over Specification…
● Holds the relative paths to the individual channel and their operations.
Each channel documentation is enhanced by following features:
30
Channels
(queue/topic/destination
name)
Reference
structure ($ref)
description
Operation
(Subscribe
Publish)
Parameters
Bindings
Channels

31. Walk through over Specification…
● Publish or a subscribe operation, sets how messages are sent and
received
31
Operation
(publish/subscribe)
operationId
Metadata
summary
description
Tags
externalDocs
bindings
traits
message
Operation

32. Walk through over Specification…
32
Operation Trait
● Aims to define/apply common patterns over operation attributes
Operation
trait
operationId
Metadata
summary
description
Tags
externalDocs
bindings

33. Walk through over Specification…
● Describes a message received on a given channel and operation.
● Headers & Payload follows a schema Object
● Message type specified by multiple messages, but valid only by one
33
title, type, required, multipleOf, maximum,
exclusiveMaximum, minimum, exclusiveMinimum,
maxLength, minLength, pattern, maxItems,
minItems, uniqueItems, maxProperties,
minProperties, enum, const, examples, if / then /
else, readOnly, writeOnly, properties,
patternProperties, additionalProperties,
additionalItems, items, propertyNames, contains,
allOf, oneOf, anyOf, not,
Schema Object
Message – Headers / Payload

34. Walk through over Specification…
● Attribute useful on tracing & tracking workflow of event
● Setting up its location upon Runtime Expressions
● Built under following expression:
34
expression = ( "$message" "." source )
source = ( header-reference | payload-reference )
header-reference = "header" ["#" fragment]
payload-reference = "payload" ["#" fragment]
fragment = a JSON Pointer
Correlation ID & Runtime Expression
Runtime Expressions

35. Walk through over Specification…
● Defines message payload. Default Schema Object.
● Supported schema formats
35
Message - Schema Format
Schemas Allowed values
AsyncAPI 2.0.0
Schema Object
application/vnd.aai.asyncapi;version=2.0.0
application/vnd.aai.asyncapi+json;version=2.0.0
application/vnd.aai.asyncapi+yaml;version=2.0.0
This is the default
when
a schemaFormat is
not provided.
OpenAPI 3.0.0
Schema Object
application/vnd.oai.openapi;version=3.0.0,
application/vnd.oai.openapi+json;version=3.0.0,
application/vnd.oai.openapi+yaml;version=3.0.0
JSON Schema
Draft 07
application/schema+json;version=draft-07,
application/schema+yaml;version=draft-07
Avro 1.9.0
schema
application/vnd.apache.avro;version=1.9.0,
application/vnd.apache.avro+json;version=1.9.0,
application/vnd.apache.avro+yaml;version=1.9.0

36. Walk through over Specification…
● Patterns/validations on Message attributes
● Message structure
36
Message - Traits
Message
Trait
headers
correlationId
schemaFormat
contentType
Metadata
Name
title
summary
description
Tags
externalDocs
bindings
Examples

37. Async API vs RAML Spec
37
1. INFO
2. Resources
3. Methods
4. Headers & Request | Response
5. Data types
6. Resource Types & Traits
7. Security schemes
1. INFO
2. Channels
3. Operation
4. Message
5. Components
6. Traits
7. Security schemes

38. Demo

39. Demo
39
flight-notifications-
publisher-api
Anypoint MQ
flight-notifications-
subscriber-api

40. Networking time
Introduce yourself to your neighbor

41. Q & A

42. Quiz - MuleSoft Vouchers

43. Thank you!