Introduction to Apache Synapse
Hiranya Jayathilaka([email protected])
What to Expect…
• The problem and the solution– Integration problems in enterprise
• Introducing Apache Synapse– Architecture and the functional components
• Case Studies– Synapse in action
• Finishing touches– Extension points and next steps
The Problem & The Solution
Software in Enterprise
• Large enterprises have many software systems– Enterprise resource planning applications– Management information systems– Decision support systems– Executive support applications
• The systems are often independent• But they are all parts of a larger business
process
Need for Enterprise Integration
• Individual software systems cannot achieve much
• Systems should be integrated to work together– Enables free data flow across the firm– Each application becomes aware of the ‘big
picture’– Improves operational and management
efficiency
Easier Said Than Done!
• Integrating a multitude of complex applications is no child’s play
• Systems are diverse (way too diverse)– Different platforms (OS and program runtime)– Different programming languages– Different messaging standards and protocols– Different QoS requirements
Is It Possible at All?
ESB to the Rescue!
• A software architecture construct that provides fundamental services for complex architectures– Message routing– Message transformation– Protocol switching– Adding QoS to message flows– And everything else integration architects
would ever need
ESB Explained!
• An architectural style or an piece of software that resembles a physical data bus
• Applications communicate via the bus, which acts as a message broker
• Replaces direct contact between software – Reduces coupling
• Based on industry standards
ESB Saves the Day!
Introducing Apache Synapse
What is Apache Synapse?
• A high performance ESB implementation– Fast– Lightweight– Low resource usage
• Easy to configure and deploy• Developed as a middleware with many
extension points• Very mature and stable code base
Key Features
• Supports many messaging standards – SOAP 1.1/1.2 and WS* standards– REST/POX
• A wide range of communication protocols– HTTP/S, JMS, Mail, VFS, FIX, AMQP
• Load balancing and fail over support• Task scheduler and the eventing mode• JMX monitoring support
Architecture
• Non blocking HTTP transport– Network IO do not hog server worker threads– Based on Apache HTTP Core NIO
• Multithreaded mediation engine• Streaming model
– The byte stream coming over the wire is ‘streamed’ through the mediation engine
– Powered by Apache AXIOM
Functional Components
• Responsible for processing messages inside the ESB and coordinating bus activities
• Can be combined, mixed and matched to implement complex message flows and enterprise integration patterns
• The task of configuring Synapse is most of the time putting the right set of functional components together
Mediators
• The simplest functional component• Takes an input message, performs some
action on it and outputs the processed message
Sequences
• A cascading chain of mediators• Input messages are sent through all the
child mediators of the sequence• Resembles an industrial pipeline
Endpoints
• Defines an endpoint reference (EPR) to which messages can be sent/forwarded from Synapse
• Various operational constraints can be enforced on endpoints– Timeout configuration– Message format (SOAP 1.1/1.2, POX)– QoS expectations (WSSecurity, WSRM)
Proxy Services
• Acts like a virtual service that can accept requests from clients
• Received client requests are processed and forwarded to an actual service implementation
• Response from the backend service is processed and routed back to the clients
Other Components
• Scheduled Tasks– Used to run a programmed activity periodically
• Event sources– Enables Synapse to act as an event broker in an
event driven architecture
• Local entries– Used to store small configuration/data items
• Registry– A metadata store for your SOA
Configuration Model
• Synapse configuration language is used to define, configure and combine functional components
• XML based• Very intuitive – Easy to learn, understand
and remember• Entire configuration goes into the
synapse.xml file
Case Studies
Case Study 01
• Problem:– How to expose an existing service over a
different schema?
• Solution:– All the incoming requests should be transformed
into the format expected by the service– All the responses should be transformed to the
format expected by the client
Solution Structure
Demonstration
Case Study 02
• Problem:– How to expose an existing HTTP service over
JMS?
• Solution:– A new (virtual) service should be created to
accept messages over JMS– The virtual service should forward the
messages to the existing service over HTTP
Solution Structure
Demonstration
Want to Try More?
• Apache Synapse is shipped with a large number of sample configurations that you can try out of the box
• Follow the samples guide included in the distribution or refer the online version of it: – http://synapse.apache.org/Synapse_Samples.html
• Java and Apache ANT are required to try out the samples
Finishing Touches
Extension Points
• Custom mediators• Custom tasks• Script mediator• POJO command mediator• Spring mediator• Transport receivers and senders• Load balance algorithms• Message formatters and builders
Feel Like Contributing?
• Project website– http://synapse.apache.org
• Code base– https://svn.apache.org/repos/asf/synapse
• Mailing lists– http://synapse.apache.org/maillists.html
• JIRA Issue tracker– http://issues.apache.org/jira/browse/SYNAPSE
Questions?
Thank You!