A SMALL RIDE WITH CAMELSunitha Raghurajan

WHAT IS APACHE CAMEL

Apache Camel is a powerful Open Source Integration Framework based on known Enterprise Integration Patterns

http://camel.apache.org

INTEGRATION PATTERNS

 A design pattern is a general reusable solution to a commonly occurring problem within a given context in software design

Patterns don’t desribe a problem, and don’t describe how to solve it-they tell you what to do to solve it (Ref:Enterprise Integration Pattern)

WHY THE NAME CAMEL

Concise Application Messaging Exchange Language

http://camel.apache.org/why-the-name-camel.html

WHO ARE CAMEL’S PARENTS

WHAT IS APACHE SERVICE MIX

Lightweight Open Source ESB and SOA Container

Built on JBI Specification

Supports OSGi

Can run as a standalone ESB provider or as a service within another ESB

ESB

Platform

Architecture Component

Product

ESB

Simplifies Integration and flexible reuse of business components using Service Oriented Architecture

Glue that holds the compound application together

WHAT IS ESB

http://i.msdn.microsoft.com/Cc487894.bddfbe7f-6ee2-4072-91f1-402c87ee92ad(en-us,MSDN.10).png

ESB ARCHITECTURE ESB Delivers messages from one point to another

Bus architecture uses a central messaging backbone (bus) for message propagation.

Applications would publish messages to bus using adapters.

These messages would flow to subscribing applications using message bus.

Subscribing applications will have adapters which would take message from bus and transform

the message into a format required for the application.

BUS ARCHITECTURE

Messaging Backbone

App AAdapter

App BAdapter B

App CAdapter C

Adapter KApp K

Adapter GApp G

Adapter ZApp Z

ESB ARCHITECTURE

WHAT IS SOA

Service-Oriented Architecture (SOA) is an architectural style.

Applications built using an SOA style deliver functionality as services that can be used or reused on a network.

Each service would achieve a predefined business objective and perform discrete units of work.

The services are independent and do not depend on the context or state of the other services. They work within distributed systems architecture

WHAT IS A SERVICE

A service is a reusable component that can be used as a building block to form larger, more complex business-application functionality.

A service may be as simple as “get me some person data,” or as complex as “process a disbursement.”

WHY MESSAGING

Asynchronous operation − Send and Forget Approach

− Sender doesn’t have to wait for the receiver to receive and process the message

Variable Timing

Disconnected Operation

Loose Coupling− Systems connected via messaging need not be

aware of each other, or use the same technologies

− Key messages can easily be routed to many systems Message broker is buffer in case of downtime

WHY MESSAGING

Remote Communication

Platform/Language Integration communicate different systems running

different platforms, using different languages

WHY MESSAGING

Parallelize Work − Messages in a single stream can be

handled in parallel by many client threads or systems

Throttle Work − A large amount of work can be split

across a small number of threads or systems to throttle effort

MESSAGING CONCEPTS

Each message is sent to a particular named “destination” (a topic or queue) Each message to a queue is processed by exactly one consumer Typically, one of many connected

consumers Each message to a topic is processed by all

the consumers connected to that topic − May even be saved for consumers that

happen to be disconnected at the moment

MESSAGE BROKER  

Message Broker

Decouple the destination message from the SenderAnd maintain central control over the flow

Of messages

MESSAGING CONCEPTS

MessageProducer

Message Consumer

Message Consumer

Message Consumer

Message BrokerMessage Broker

Topic Queue

ACTIVE MQ

Apache ActiveMQ is an open source (Apache 2.0 licensed) message broker which fully implements the Java Message Service 1.1 (JMS)

JMS The Java API for messaging

CHARACTERISTICS OF ESB

TransactionManagementTransaction

ManagementService Orchestration

Service Orchestration

Message ProcessingMessage

Processing

Service MappingService MappingMessage Transformation

Message Transformation

RoutingRouting

SecuritySecurity

Message Enhancement

Message Enhancement

Protocol Transmission

Protocol Transmission

OSGI

The Open Services Gateway Initiative (OSGi) Dynamic Module System for Java Architecture for modular application development.

JBI

JBI is a java based standard to build integrations systems by using plug-in components which interoperates through mediated normalized message exchanges.

The message exchange model is based on the web services description language (WSDL).

BACK TO CAMEL RIDE

50 Enterprise Integration Patterns

http://camel.apache.org/eip

APACHE CAMEL (INSIDE THE BOX)80 COMPONENTS

activemq cxf flatpack jasypt

activemq-journal

cxfrs freemarker javaspace

amqp Dataset ftp/ftps/sftp jbi

atom Db4o gae jcr

bean direct hdfs jdbc

bean validation ejb hibernate jetty

browse esper hl7 jms

cache event http jmx

cometd exec ibatis jpa

crypto file irc jt/400

http://camel.apache.org/components.html

CAMEL (WHAT IS INSIDE )18 DATA FORMATS

bindy protobufcastor serialization

csv soapcrypto syslogdozer tidy markup

flatpack xml beansgzip xml securityhl7 xstreamjaxb zipjson

CAMEL(INSIDE THE BOX)15 EXPRESSION LANGUAGES

BeanShell Python

EL Ruby

Groovy Simple

JavaScript SpEL

JSR 223 SQL

OGNL XPath

MVEL XQuery

PHP

Domain Specific Language

Domain-specific language ● Routing can be defined in DSL ● Java DSL Fluent API that allows code completion by your IDE ● Spring DSL Custom namespace with XML tags for routing ● Scala DSL Adding some Scala features on top of the Java DSL

Questions

REFERENCES

http://ggatz.com/images/Enterprise_20Integration_20-_20SOA_20vs_20EAI_20vs_20ESB.pdf

Camel in Action http://manning.com/ibsen