This document discusses agile integration architecture from three perspectives: application integration, APIs, and messaging. It outlines how traditional centralized integration approaches are moving to more decentralized models with fine-grained deployments, application autonomy, and cloud-native implementations. APIs are shifting from system-centric to consumer-centric exposure, while messaging is evolving from self-managed to platform-managed infrastructure. Microservices require both asynchronous communications via events and synchronous APIs to fully decouple components. Agile integration architecture enables independent, scalable, and resilient digital applications and services.

1. IBM Cloud / DOC ID / Month XX, 2018 / © 2018 IBM Corporation
Agile Integration Architecture
in relation to APIs and messaging
Recording: http://ibm.biz/AgileIntegArchApiMessagingWebinar
Kim Clark
Integration Architect
Integration Portfolio

2. Integration modernization through
Agile Integration Architecture
1
A. Fine grained deployment
B. Decentralized ownership
C. Cloud native infrastructure
API API API
API
API
API
API APIAPI
Traditional application integration
(centrally provisioned and administered silo)

3. Perspectives on
Agile Integration Architecture
Application
Integration
perspective
API
perspective
M
essaging
perspective
Agile Integration Architecture

4. Perspectives
Application
Integration
perspective
API
perspective
M
essaging
perspective
Agile Integration Architecture

5. Integration modernization
Application Integration perspective
4
Traditional application integration
(centrally provisioned and administered silo)
Isolated integration deployment,
application ownership,
cloud-ready implementation

6. The fate of the ESB Pattern: Moving to agile integration architecture
http://ibm.biz/AgileIntegArchPaper
Containerization
Centralized
ESB
Fine-grained
integration
deployment
Application autonomy Polyglot runtimes
Decentralized
integration
ownership
Integration as a
microservice runtime
http://ibm.biz/AgileIntegArchWebinar

7. Perspectives
Application
Integration
perspective
API
perspective
M
essaging
perspective
Agile Integration Architecture

8. Integration modernization
API Management perspective
7Accelerate digital transformation with Cloud & AI / July 2018 / © 2018 IBM Corporation
Traditional SOA exposure
API exposure
Consumer-centric, channel optimized
Distributed gateways
Self-service discovery, developer portals
Subscription and version management
Self-provisioned and administered
Internal and external
API
Service exposure
System centric
Single gateway
Waterfall delivery
Re-use focused
Mostly internal
API API
API
API
API
API
API API
API

9. Agile integration architecture and API management
Containerization
Centralized
ESB
Fine-grained
integration
deployment
Application autonomy Polyglot runtimes
Decentralized
integration
ownership
Integration as a
microservice runtime

10. API management: More than just a gateway
Developer
Portal
API
Manager
API Gateway:
• Decoupling/routing
• Traffic management
• Security
• Translation
Developer portal:
• API discovery
• Self-service
• Onboarding
• API subscription
• Account usage analytics
API Manager:
• API/plan/product design
• Access management
• Policy administration
• API plan usage analytics
The API implementation should not be burdened with the
complexities of API exposure beyond the microservices
application boundary. Exposure should be delegated to a
separate capability providing as a minimum, a gateway, a
developer portal, and API management.
API Implementation
API gateway

11. Decentralized API ownership
Developer Portal
API Manager
API
Implementation
A
API
Implementation
B
API
Implementation
C
A B C
A B C
API gateway API gateway API gateway
on a centralized API management infrastructure
API gateway

12. On premises
Federated API gateways, centralized management
Developer
Portal
API
Manager
Public Cloud A
Private
Cloud
Public Cloud Y
Public
Cloud Z
API gateway
API gateway
API gateway
API gateway
API gateway

13. µService
µService
µService µService
µService
API gateway
API
Application
boundary
µService
Microservice
component
µService
µService
µService
API gateway
API gateway
µService
API gateway
Silo
application
API gateway
Silo
application
Managed API gateways define and enforce application boundaries
Boundaries make complex environments manageable
µService
µService
µService
API gateway
µService
µService
µService
API gateway
µService
µService
µService
API gateway

14. Microservice
component
Inter-microservice vs. inter-application communication
Microservices
application
Microservice
component
Microservice
component
Microservices
application
Exposure Gateway
Inter-application communication
• Crosses organizational boundaries
• Potentially on different platform
• API management advised
Inter-microservice communication
• Within an organizational boundary
• Microservices on shared platform
• Service mesh (e.g. Istio) for complex
routing
• API management optional
Note: the protocol used for the communication may be the
same in both cases, (e.g. JSON/HTTP). It is the way that
the interfaces are exposed and managed that is different.
JSON/HTTP
JSON/HTTP

15. Perspectives
Application
Integration
perspective
API
perspective
M
essaging
perspective
Agile Integration Architecture

16. Integration modernization
Messaging perspective
15Accelerate digital transformation with Cloud & AI / July 2018 / © 2018 IBM Corporation
Traditional application pervasive, self-
managed messaging topologies Self-provisioned, platform-managed, secure, reliably
and transparent communication in a multi-cloud
environments. Delivering an event driven enterprise.

17. Local vs Remote messaging
16
Local message store/forward,
ensures “put” is always possible
Additional process alongside application to enable inter-process
communication – against best practice for containers.
Local persistence required, which
complicates HA/DR scenarios
Messaging is a local component
Network connectivity assumed/required for “put”, moving
burden of local store/forward on client if network fails
Application is standalone single process,
so well suited to containers
No local persistence requirement, enabling
simplistic stateless HA/DR for application
Messaging can be consumed as-a-service

18. asynchronous(messaging,events,…)
trad. on premisescloud platform
cloud platformcloud platform
private cloudSaaS platform
iPaaS/iSaaS
SaaS platform
cloud platform cloud platform
The asynchronous backplane (messaging, events)
The asynchronous backplane provides reliable message/event storage and a
distribution network that can traverse application and cloud boundaries robustly.

19. Microservice Application
Creating truly independent digital applications requires
asynchronous communications as well as APIs
SoR SoR SoRSoR
APIs
invocations
EventStreams
Truly independent, decoupled microservice components enable
• Agility: Innovate rapidly without affecting other components
• Scalability: Scale only what you need, and only when you need to
• Resilience: Fail fast, return fast, without affecting other components
To provide those benefits they need to be independent of the systems of record
• APIs: Are simplest to use, but create a real-time dependency
• Event streams: Enable microservices to build decoupled views of the data
µService
µServiceµService
µService µService
µService µServiceµService
µService
API gateway
Enterprise integration

20. Source / Target
Request / Reply
Stream History
Transient Data
Persistence
Immutable Data
Scalable
Consumption
Targeted
Reliable Delivery
Events
(notifications)
Messaging
(commands)
ü
19

21. Perspectives on
Agile Integration Architecture
Application
Integration
perspective
API
perspective
M
essaging
perspective
Agile Integration Architecture

22. Agile integration architecture eBooklet
https://www.ibm.com/cloud/agile-integration-architecture
summarises the following source material
Public material
on integration
modernization
The evolving hybrid integration reference architecture
https://ibm.biz/HybridIntRefArch
http://ibm.biz/HybridIntRefArchYouTube
“Microservices, SOA, and APIs: Friends or enemies?”
https://ibm.biz/MicroservicesVsSoa
http://ibm.biz/MicroservicesVsSoaWebinar
Agile Integration Architecture
http://ibm.biz/AgileIntegArchPaper
http://ibm.biz/AgileIntegArchWebinar
The fate of the ESB
http://ibm.biz/FateOfTheESBPaper
Useful links on agile integration architecture
http://ibm.biz/AgileIntegArchLinks
https://developer.ibm.com/apiconnect/blog
https://developer.ibm.com/integration/blog
https://developer.ibm.com/messaging/blogs
Staying up to date:

23. 22Think 2018 / DOC ID / Month XX, 2018 / © 2018 IBM Corporation