The document summarizes a meetup discussing custom policies and asynchronous APIs in MuleSoft. The meetup included presentations on developing custom policies for Mule 4 applications and introducing asynchronous APIs. The custom policy presentation covered topics like inbound and outbound custom policies, error handling, and YAML configuration. The asynchronous API presentation provided an introduction to event-driven architecture and asynchronous APIs, their benefits, and how they are supported in Anypoint Platform. The meetup concluded with a networking session for attendees.

1. 29-JAN-2022
Noida MuleSoft Meetup Group
Custom Policy & Async API

2. 2
● Introductions
● Custom Policy.
● Async API
● Networking time
Agenda

3. 3
Organizer
Speakers
Introductions
A SHOW OF HANDS:
Who is new to this Meetup?

4. Mihir Sao
Lead Engineer at Apisero
Custom Policy

5. 5
Agenda
Prerequisites & Setup
01
Inbound Custom Policy
02
Outbound Custom Policy
03
Exception Handling from Custom policy
04
YAML configuration File &
Classloading Isolation
05

6. 6
The current workflow to get a working policy for Mule 4 that can be applied in Anypoint Platform
consists of:
○ Develop the policy.
○ Package the policy.
○ Upload the resulting policy assets to Exchange.
○ Apply the policy to any API through API Manager.
Steps

7. 7
Configuring Maven’s settings.xml with the following section:
Setting up a project with the archetype

8. 8
Configuring Maven’s settings.xml with the following section:
Setting up a project with the archetype

9. 9
Inbound custom policy event flow
<A1> -> <F1> -> <A2>

10. 10
Multiple Inbound custom policy event flow
<A1> -> <B1> -> <F1> -> <B2> -> <A2>

11. 11
Mule message propagation in source policies

12. 12
Mule message propagation in source policies

13. 13
Mule message propagation in source policies

14. 14
Outbound custom policy event flow
<F1> -> <A1> -> <http:request> -> <A2> -> <F2>
<http-policy:proxy name="policy-A">
<http-policy:operation>
<A1 />
<http-policy:execute-next/>
<A2 />
</http-policy:operation>
</http-policy:proxy>

15. 15
Mule message propagation in operation policies
<http-policy:proxy name="scope-payload">
<http-policy:operation>
<set-payload value="Policy Message" />
<http-policy:execute-next/>
</http-policy:operation>
</http-policy:proxy>
Consumer
Provider

16. 16
Mule message propagation in operation policies
<http-policy:proxy name="scope-payload">
<http-policy:operation>
<http-policy:execute-next/>
<set-payload value="Policy Message"
/>
</http-policy:operation>
</http-policy:proxy>
Consumer

17. 17
Mule message propagation in operation policies
<http-policy:proxy name="scope-payload"
propagateMessageTransformations="true" >
<http-policy:operation>
<http-policy:execute-next/>
<set-payload value="Policy Message"
/>
</http-policy:operation>
</http-policy:proxy>
Consumer

18. 18
Inbound and Outbound custom policy EF
<A1> -> <F1> -> <A3> -> <http:request> -> <A4> -> <F2> -> <A2>

19. 19
Multiple Inbound and Outbound custom policy EF
<A1> -> <B1> -> <F1> -> <A3> -> <B3> -> <http:request> -> <B4> -> <A4> -> <F2> -> <B2> -> <A2>

20. 20
<flow name="flow">
<http:listener />
<F1 />
<F2 />
<error-handler>
<on-error-continue>
<FEH />
</on-error-continue>
</error-handler>
</flow>
Error Handling in custom policy
Error occurs on P1: <P1> -> <PEH>
<flow name="flow">
<http:listener />
<F1 />
<F2 />
<error-handler>
<on-error-propagate>
<FEH />
</on-error-propagate>
</error-handler>
</flow>
Service 1
Service 2

21. 21
<flow name="flow">
<http:listener />
<F1 />
<F2 />
<error-handler>
<on-error-continue>
<FEH />
</on-error-continue>
</error-handler>
</flow>
Error Handling in custom policy
Error occurs on F1 in Service 1: <P1> -> <F1> -> <FEH> -> <F2> -> <P2>
<flow name="flow">
<http:listener />
<F1 />
<F2 />
<error-handler>
<on-error-propagate>
<FEH />
</on-error-propagate>
</error-handler>
</flow>
Service 1
Service 2

22. 22
<flow name="flow">
<http:listener />
<F1 />
<F2 />
<error-handler>
<on-error-continue>
<FEH />
</on-error-continue>
</error-handler>
</flow>
Error Handling in custom policy
Error occurs on F1 in Service 2: <P1> -> <F1> -> <FEH> -> <PEH>
<flow name="flow">
<http:listener />
<F1 />
<F2 />
<error-handler>
<on-error-propagate>
<FEH />
</on-error-propagate>
</error-handler>
</flow>
Service 1
Service 2

23. 23
YAML configuration File

24. 24
HandleBars {{{}}}
{{{exposeHeaders}}}

25. 25
Classloading isolation

27. Vyshnavi Jaksani
Lead Engineer at Apisero
Async API

28. 28
Agenda
Introduction to Event driven Architecture
01
Introduction to Async API
02
Async API in Anypoint Platform
03
Benefits of using Async API
04

29. Event Driven Architecture
29

30. Need for Event Driven Architecture
30

31. Example of Event Driven Architecture
31

32. Issues in Synchronous processing
32

33. Issues with Event Driven Architecture
Developers lack visibility into existing events, their current use, and details on how to reuse
an existing event.
IT teams lack industry-standard best practices and conventions for defining machine and
human-readable event driven APIs.
Developers need to work with multiple protocols(JMS, MQ, Kafka, SNS etc) which can be
challenging.
33

34. 34
Async API

35. Async API support in Anypoint Platform
35
Design: In Design Center , we can create Async API specification or import one from Anypoint
Exchange.
Publish: In Anypoint Exchange, we can add non-managed instances to our Async API asset.
Note: Anypoint Studio and Flow Designer do not support Async API. If we try to import Async API
in Anypoint studio, an error message will be displayed.

36. Components of Async API
36
Events: Message or data to be shared with other services.
Channels: Destination of the message to be sent or received.
Transport: Technology that transports the message, such as Rabbit MQ, Kafka, Anypoint MQ etc.

37. Discover Reusable Assets
37

38. Demo

40. TAKE AWAY

41. 41
● Kickstart to understand Event Driven Architecture.
● Advantages of using Event Driven Architecture.
● Challenges of using Event Driven Architecture.
Take away

42. 42
● Share:
○ Tweet using the hashtag #MuleSoftMeetups
○ Invite your network to join: https://meetups.mulesoft.com/noida/
● Feedback:
○ Fill out the survey feedback and suggest topics for upcoming events
○ Contact MuleSoft at meetups@mulesoft.com for ways to improve the program
What’s next?

43. Introduce yourself to your neighbor
Networking time

44. Thank you
For investing your time and participating