Microservices architecture redefined the concept of a modern application as a set of independent, distributed, and loosely coupled services running in the cloud. Spring Cloud Stream is a framework for building these services and connecting them with shared messaging systems. In this hands-on session, we’ll look at some of the new features and enhancements that are already part of the 2.0 line, and discuss what we’re working on and what to expect. Presenter : Oleg Zhurakousky, Pivotal

1. Spring Cloud Stream - developer
recipes, what’s new and what’s next?
Oleg Zhurakousky
@z_oleg
1

2. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Disclaimer - fine print
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3. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Scope
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• What is Cloud?
• What is Event and Event driven Architecture?
• Streaming
• Putting it all together with Spring Cloud Stream
• What’s new in 2.0?
• What’s next?

4. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Cloud
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• Ecosystem that integrates platforms and middleware into one cohesive hybrid
runtime.
• Messaging (JMS, AMQP, Kafka, etc.)
• File Systems
• Databases
• Etc. . .
• Outsources infrastructure concerns to the cloud provider via cloud connectors/
services
• Provides mechanism for applications services (clients) to interact with cloud
services.
• Event oriented

5. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Events
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• Event - representation of a state change
• Always in past tense
• Events are delivered in a form or protocol specific records using some Messaging
middleware.
• Many delivery mechanisms
• HTTP (REST)
• Publish/Subscribe
• variation of pipes-and-filters pattern
• multiple subscribers
• Events contain meta-data (i.e., event type)
• Event = Message
Message

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Stream
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• Stream - processing graph
• Event (Message) is injected into the graph operators
• Graph operators pass events between one another
• Processing graphs could run in sequence or parallel
︎
︎
stream.flatMap(event -> multipleEvents).map(event -> newEvent). . .︎

7. Putting it together
Spring Cloud Stream

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Spring Integration
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• Messaging framework which provides implementation of EIP
on top of Spring Messaging

9. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Integration
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• Pros/Cons
• Handles message dispatching while exposing POJO-based flexible
application development model
• Shares resources

10. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Cloud Stream
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• Framework to build highly scalable event-driven and/or streaming microservices.
• Provides boot-driven integration with Messaging Brokers using Destination Binders
• Leverages native features of brokers while also providing a workaround for not
supported features.
• Partitioning
• Consumer Groups
• Message Headers
• Destination provisioning
• Honors application configurations by the underlying frameworks (spring-integration,
spring-kafka etc.)
• Kafka & Rabbit are currently supported

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Spring Cloud Stream
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• Transparent content-type negotiation and argument resolution
• Ability to connect microservices to external systems
• Kafka
• Rabbit MQ
• JMS
• Etc. . .
• Provides flexible programming model
• Built on familiar Spring idioms - Spring Messaging
• Supports pub/sub semantics, consumer groups, stateful partitions and other messaging paradigms
• Message centric
• Supports Imperative and Declarative programming models
Message

12. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Cloud Stream - programming model
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• Imperative
• Declarative

13. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Cloud Stream
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14. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Cloud Stream - programming model
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• Spring Cloud Stream - Spring Boot app
• Flexible configuration (i.e., Annotation, XML, hybrid)
• Binders
• Streaming
• KStream
• Channel-based
• Kafka
• Rabbit
• Seamless integration with the rest of the Spring Cloud stack
• Metrics
• Sleuth
• Config
• Circuit Braker
• Etc.

15. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Cloud Stream - summary
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• Durable Publish-Subscribe messaging
• For easily creating complex topologies
• Consumer groups
• Multiple instances can be competing consumers when scaling
• Declarative data partitioning
• Colocating related data in consumer instances (Kafka, Rabbit etc)

16. Putting it together
Spring Cloud Stream - DEMO

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What’s new in 2.0?
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• Improved Content-type negotiation
• Default content-type
• User-defined message converters
• Polling Consumer
• New Actuator endpoints for Binding control
• Metrics - based on Spring Boot support for Micrometer
• Native support for Apache Kafka streaming
• https://youtu.be/YPDzcmqwCNo (Josh Long)
• Web support is now optional
• Deprecation of Java-based serialization
• Revamped user guide

18. Where do we go from here?

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Things to think about. . .
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• Bridge-based binding
• source/target to SI channels
• user must be aware of Spring, SI and other (dispatching, message immutability etc)
Rabbit queue -> SI channel -> Argument Resolution -> user code -> SI channel -> conversion to wire - target exchange
• Spring Cloud Stream infrastructure mixed with functional code
• @EnableBinding
• Complex message processing use cases (batching/windowing, transactions etc)
• Serverless (Java 8 Functions)
• Event based
• Dynamic resource utilization "scale to 0"
• Focus on business logic
• Easy integration with platform services (binders)
• Cross platform (SCF adapters AWS, Azure, Openwhisk etc)
• Source/Sink conceptual mismatch (is source and app or just a source?)

20. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/
Spring Cloud Stream - programming model
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• Imperative
• Declarative

21. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Source/Sink conceptual missmatch
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Type to enter a cap/on.

22. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Serverless/Functions
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Type to enter a cap/on.

23. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Direct Binding & Function composition
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Type to enter a cap/on.

24. Unless otherwise indicated, these slides are © 2013-2017 Pivotal Software, Inc. and licensed under a Creative
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Spring Cloud Functions - cross platform
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Type to enter a cap/on.

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Spring Cloud Stream - Links
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• http://cloud.spring.io/spring-cloud-stream
• https://github.com/spring-cloud/spring-cloud-stream
• https://github.com/spring-cloud/spring-cloud-stream-binder-kafka
• https://github.com/spring-cloud/spring-cloud-stream-binder-rabbit

26. Learn More. Stay Connected.
Thank you!
@z_oleg
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