This talk explores the new possibilities for scale by using Spring Integration, Spring Batch and RabbitMQ on Cloud Foundry, the open source PaaS from VMWare.

1. Enterprise Application Integration and
Batch Processing in the Cloud
Josh Long, Spring Developer Advocate
josh.long@springsource.com @starbuxman
© 2012 SpringOne 2GX. All rights reserved. Do not distribute without permission.

2. Josh Long
Spring Developer Advocate
josh.long@springsource.com @starbuxman
2

3. Worker processes on Cloud Foundry

4. Lots of Potential
 http://blog.springsource.org/2012/05/09/using-cloud-foundry-workers-with-spring/
 lots of use cases ---
applications:
• background jobs target/appassembler/:
• headless applications name: integration-service
• batch jobs framework:
• embedded web servers name: standalone
info:
mem: 64M
description: Standalone Application
exec:
runtime: java
command: bin/main
url:
mem: 512M
instances: 1
services:
stock_rabbitmq:
type: rabbitmq
4

5. Easy to Package Multi-component Java applications
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>appassembler-maven-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>assemble</goal>
</goals>
<configuration>
<assembledirectory>target</assembledirectory>
<programs>
<program>
<mainClass>org.cloudfoundry.workers.stocks.integration.service.Main</mainClass>
</program>
</programs>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
5

6. Cloud Scale Messaging with RabbitMQ

7. First, an Introduction to
AMQP & RabbitMQ

8. Messaging Use Cases
Decoupling
producer consumer
shopping cart sending request CC merchant
NOT CONFIDENTIAL -- TELL EVERYONE 8

9. Messaging Use Cases
Bidirectional Decoupling
producer consumer
eg: remote procedure call
NOT CONFIDENTIAL -- TELL EVERYONE 9

10. Messaging Use Cases
Bidirectional Decoupling
producer producer
consumer
eg: place order and wait for confirmation
NOT CONFIDENTIAL -- TELL EVERYONE 10

11. Messaging Use Cases
Bidirectional Decoupling
producer consumer producer
consumer
eg: place order and wait for confirmation
NOT CONFIDENTIAL -- TELL EVERYONE 11

12. Messaging Use Cases
work distribution and decoupling
consumer
producer consumer
distribution can be duplicate or round-robin:
- duplication for information (logging, auditing, etc)
- round robin for scaling and load balancing
NOT CONFIDENTIAL -- TELL EVERYONE 12

13. Messaging Use Cases
 Other Things a Message Broker Can Do
• Store-and-forward of messages
• Absorbing spikes of activity (again, decoupling)
• Routing to different consumers based on message properties
NOT CONFIDENTIAL -- TELL EVERYONE 13

14. AMQP and JMS
How does AMQP compare to JMS?
When would I use one or the other?
NOT CONFIDENTIAL -- TELL EVERYONE 14

15. AMQP and JMS
AMQP JMS
Protocol API
No language Java
Industry committee, mainly finance JEE
Interoperability from client libraries Interoperability from proprietary features
Resources can be managed by clients Resources often centrally managed
Not ubiquitous in enterprise Ubiquitous through JEE
Flexible usage patterns, emphasise routing Two basic producer patterns (Queue and Topic)
Designed for large numbers of queues and exchanges Hard to manage large numbers of Destinations
NOT CONFIDENTIAL -- TELL EVERYONE 15

16. AMQP and JMS
 JMS
• standard in the Java space
• lots of open source options
• provided with Java EE application servers
• Spring JMS
Java producers Message broker Java consumers
C
P queue
C
P queue
C
16

17. JMS
 Sending JMS Messages
• Inject an instance of Spring's JmsTemplate.
• Provide the JMS ConnectionFactory in the JmsTemplate bean definition.
@Component
public class MessageSender {
@Autowired
private volatile JmsTemplate jmsTemplate;
public void send(String message) {
this.jmsTemplate.convertAndSend("example.queue", message);
}
} @Bean public ConnnectionFactory cf (){
return new CachingConnectionFactory(...);
}
@Bean public JmsTemplate template(){
return new JmsTemplate(this.cf()) ;
}
17

18. AMQP and JMS
 AMQP
• real standard
• a product of the the companies with the most mission critical requirements
• Spring AMQP
AMQP producers exchanges Message broker AMQP consumers
C
P X queue
C
P X queue
C
1

19. AMQP and JMS
 JMS Topic Explosion:
• Messages with fine-grained routing, e.g.
• Market data: region, country, exchange, ticker, …
• Online gambling: sport, match, event-type, …
• Message selectors are inefficient and fiddly to work with in the API
• Exponential explosion of possible combinations of interesting subscriptions
• Can implement as hierarchy of Topics
• 1000s or 10000s of Destinations
• Management nightmare
• Sweet spot for AMQP
NOT CONFIDENTIAL -- TELL EVERYONE 19

20. AMQP
 Sending AMQP Messages
• Use AmqpTemplate instead of JmsTemplate (accepts exchange and routingKey).
• Nothing changes on the listener side (just a POJO).
@Component public class MessageSender {
@Autowired
private volatile AmqpTemplate amqpTemplate;
public void send(String message) {
this.amqpTemplate.convertAndSend(
"myExchange", "some.routing.key", message);
}
}
20

21. Spring AMQP
 Java and .NET
 AMQP core abstraction plus RabbitMQ implementation (built on rabbit client libraries)
 Higher level patterns for clients: admin, producers and consumers
 RabbitAdmin – declare exchanges, queues, bindings
 RabbitTemplate – convenience methods for send and receive
 MessageListenerContainer – POJO message handler, asynchronous
 Spring Integration support
http://www.springsource.org/spring-amqp
NOT CONFIDENTIAL -- TELL EVERYONE 21

22. Spring AMQP: RabbitTemplate
public class MyComponent {
private RabbitTemplate rabbitTemplate;
public MyComponent(ConnectionFactory connectionFactory) {
this.rabbitTemplate = new RabbitTemplate(connectionFactory);
}
public void read() throws Exception {
...
String value = rabbitTemplate.receiveAndConvert("myQueueName");
...
}
}
Convenience methods
NOT CONFIDENTIAL -- TELL EVERYONE 22

23. Spring AMQP: SimpleMessageListenerContainer
 Asynchronous message receiver
 POJO handlers
 Handles re-connection and listener failure (rollback, redelivery)
 Message conversion and error handling strategies
<listener-container connection-factory="connectionFactory">
<listener ref="handler" method="handle" queue-names="my.queue">
</listener-container>
NOT CONFIDENTIAL -- TELL EVERYONE 23

24. Messaging Use Cases
 Patterns:
 spatial decoupling (aka communication)
 temporal decoupling (aka buffering)
 logical decoupling (aka routing)
 Promote: flexibility, resilience, performance, and scale
 Conclusion: There is an enormous range of applications and problems to which messaging is
an effective solution.
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25. Not confidential. Tell everyone. 25

26. Not confidential. Tell everyone. 26

27. Batch Processing in the Cloud
Not confidential. Tell everyone. 27

28. First, an Introduction to Spring Batch
Not confidential. Tell everyone. 28

29. Why we’re here...
Not confidential. Tell everyone. 29

30. ...So, What’s the Problem?
Not confidential. Tell everyone. 30

31. Job and Step
Job
* Step
*
JobInstance
Step Scope
*
JobExecution
* StepExecution
Not confidential. Tell everyone. 31

32. Getting Started
Application
Developer
implements ItemProcessor (optional)
input output (optional)
configures
ItemReader ItemWriter
Job
* StepExecutor concerns
Step
RepeatOperations ExceptionHandler
Not confidential. Tell everyone. 32

33. Spring Batch
 Supports Batch API...
• Jobs have Steps
• Steps have Readers, and optional Processors and Writers
• Readers read data
• Processors process data coming into them, optionally transforming it. Optional.
• Writers write data out
Not confidential. Tell everyone. 33

34. ItemReader
public interface ItemReader<T> {
T read() throws Exception,
UnexpectedInputException,
ParseException,
NonTransientResourceException;
}
Returns null at end of dataset
delegate Exception handling to framework
Not confidential. Tell everyone. 34

35. ItemProcessor (Optional)
public interface ItemProcessor<I, O> {
O process(I item) throws Exception;
}
Delegate Exception handling to framework
Not confidential. Tell everyone. 35

36. ItemWriter
public interface ItemWriter<T> {
void write(List<? extends T> items) throws Exception;
}
expects a “chunk”
delegate Exception handling to framework
Not confidential. Tell everyone. 36

37. All Together...
<job id="skipJob" incrementer="incrementer"
xmlns="http://www.springframework.org/schema/batch">
<step id="step1">
<tasklet>
<chunk reader="fileItemReader"
processor="tradeProcessor"
writer="tradeWriter"
commit-interval="3" skip-limit="10">
</chunk>
</tasklet>
<next on="*" to="step2" />
<next on="COMPLETED WITH SKIPS" to="errorPrint1" />
<fail on="FAILED" exit-code="FAILED" />
</step>
...
</job>
Not confidential. Tell everyone. 37

38. Partitioning Overview
Job
Step
Step
Step
Not confidential. Tell everyone. 38

39. Partitioning Overview
Job
Slave
Step
Slave
Slave
Master
Slave
Slave
Step
Slave
Not confidential. Tell everyone. 39

40. Requests
We Have a Cloud, Let’s Scale!
 Spring Batch supports Remote Chunking over AMQP
• http://labs.bsb.com/2011/11/remote-partitioning-with-spring-batch/
• http://bit.ly/wrb8Ch
master
step execution results
RabbitMQ
Step Execution
Requests
slave 1 slave 2 slave 3
Not confidential. Tell everyone. 40

41. Simple Strategy SPI for Distribution and Aggregation
Not confidential. Tell everyone. 41

42. Application Integration (in the Cloud)
Not confidential. Tell everyone. 42

43. Integration's More Common Than You Think
channel
System A
System A
System A System B
Not confidential. Tell everyone. 43
6

44. Nobody Builds Systems in a Vacuum
do NOT reinvent
the Wheel!
Not confidential. Tell everyone. 44

45. Don't over extend your architecture!
Not confidential. Tell everyone. 45

46. Rooted in Classic Patterns
• By Gregor Hohpe & Bobby Woolf
• Published 2003
• Collection of well-known patterns
• http://www.eaipatterns.com/eaipatterns.html
• Icon library provided
Not confidential. Tell everyone. 46

47. What is Spring Integration?
• Light-weight messaging framework
• Provides an adapter-based platform
• Pipes and Filters at the core of Spring Integration’s architecture
– Endpoint (Filter)
– Channel (Pipe)
– Message
Not confidential. Tell everyone. 47

48. DEMO
• Spring Integration Primer
@starbuxman slideshare.net/joshlong

49. Spring Integration @Gateway
 Gateways...
• hide one system from the messaging semantics of another
• Support all the message exchange patterns
• Request
• Request asynchronous (fire-n-forget)
• Request/Reply
• Request/Reply asynchronous (fire-n-forget)
public class CustomerService {
void addCustomer( Customer customer )
throws CrmException;
}
Not confidential. Tell everyone. 49

50. Spring Integration @Gateway
MessageChannel crmChannel = ...;
MessagingOperations operations = .... ;
operations.sendAndReceive( crmChannel ,
MessageBuilder.withPayload(new Customer(..)).build() );
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51. Spring Integration @Gateway
public interface CustomerService {
@Gateway
void addCustomer( Customer customer )
throws CrmException;
}
Not confidential. Tell everyone. 51

52. DEMO
• using Spring Integration gateways
@starbuxman slideshare.net/joshlong

53. Summary
 RabbitMQ is readily available Messaging in the Cloud
 Spring Integration makes integration over AMQP easy
 Spring Batch Makes Batch Jobs Easy
• Remote Chunking Makes Using AMQP as the Coordination Fabric Easy
Not confidential. Tell everyone. 53

54. springsource.org | cloudfoundry.org
Questions?
Say hi!
@starbuxman slideshare.net/joshlong
@starbuxman josh.long@springsource.com