Introduction
For people who are in hurry, here is the code and the steps to execute. Please also refer to my blog on Publisher/Subscriber using Spring Integration and Gemfire as the ESB.
In a Enterprise Service Bus (ESB) architecture, the “Service Bus” will become bottle neck over a period of time. In a typical ESB you write to the Bus and lot of subscribers read from the bus. Gemfire can help ESB to achieve Distributed caching, by virtue of being powerful inmemory distributed caching backbone. Claimcheck pattern is an Enterprise Integration Pattern where in a Publisher component can publish a large payload into Gemfire cache, a GUID key is generated for this payload and placed on the Topic. A subscriber in the Claimcheck pattern will be listening to the Topic for this key and get the payload from Gemfire. The Dataflow diagram is as follows,
Spring Integration Gemfire Claimcheck Pattern
Claimcheck Pattern using Spring Integration and Gemfire
There are lot of good example from David Turanski in Github to learn Spring Integration with Gemfire. In this prototype, I built a simple replicated region based server based on the idea from basic\replicated-cs example from David’s examples. In order to run this prototype, download and install Activemq and start ActiveMq and create a Topic called “MyTopic”. After that, run the Gemfire Replicated Server as below.
cd gemfire-server mvn package mvn exec:java -Dexec.mainClass="org.springframework.data.gemfire.examples.Server"
Now Maven import the claimcheck-subscriber project into STS IDE and start the tomcat instance by clicking “Run on Server” this project. The subscriber will start listening to the messages/GUID in the topic “MyTopic”
Finally publish the XML payload on to the Gemfire cache by executing below command,
cd claimcheck-publisher mvn test
In the Tomcat server console you will see below message
[Headers={timestamp=1348935448580, id=77480754-a4d8-4bc4-a529-26c9e26a7724, jms_timestamp=1348935447237, jms_redelivered=false, jms_messageId=ID:krishna-PC-62975-1348935446968-1:1:1:1:1}]
29 Sep 2012 12:17:28,702[topicContainer-1] DEBUG: com.goSmarter.gemfire.claimcheckpattern.ServiceActivator - ### PAYLOAD ###<!--?xml version="1.0" encoding="UTF-8"?-->
goSmarter
Conclusion
In this demo, I have demonstrated the claimcheck pattern. In an enterprise ecosystem, this is a basic component of claimcheck pattern. The enhancements on top of this includes various other things including,
- each subscribers doing partial checkout of payloads from Gemfire.
- it also need to have a way to work in a cluster environment.
- Implementing distribution caching
I hope this example helped you.
