High Speed SOA with Apache Synapse

Paul FremantleVP, Apache Synapse

CTO, WSO2pzf@apache.org

Contents• What is Apache Synapse• History of the project• Some examples• Delving into the model• Performance• Connectors, Adaptors• Getting started• Getting involved

What is Apache Synapse?

• Is it?– A highly performant XML Gateway– An Enterprise Service Bus– An HTTP proxy server– A protocol switcher– A way of hosting message manipulation

logic

What is Apache Synapse?• A lightweight Enterprise Services Bus (ESB)

– Available as a WAR file, NT Service, Linux Daemon – Runs as a process with its own Listeners, Tasks and

Senders– Can be deployed standalone or part of a cluster or

distributed network– High performance, asynchronous, streaming design– Can initiate work – scheduled tasks– Supports multiple transports including HTTP, JMS, TCP,

SMTP and (S)FTP– Simple to extend

HTTP8080

HTTPS8443

JMS

SMTP

inflow

log xslt send

outflow

send xslt log

HTTP8080

HTTPS8443

JMS

SMTP

Flows

Synapse startup Using Bouncy castle JAR for Java 1.5Starting Synapse/Java ...Using SYNAPSE_HOME: C:\SYNAPS~1.1\bin\..Using JAVA_HOME: c:\jdkUsing SYNAPSE_XML: -Dsynapse.xml="C:\SYNAPS~1.1\bin\..\repository\conf\synapse.xml"2007-11-12 12:16:58,250 [-] [main] INFO ServerManager Using the Axis2 Repository C:\

SYNAPS~1.1\bin\..\repository2007-11-12 12:17:01,921 [-] [main] INFO SynapseInitializationModule Initializing Synapse at :

Mon Nov 12 12:17:01 GMT 20072007-11-12 12:17:01,937 [127.0.0.1-pzfdell] [main] INFO SynapseInitializationModule Loading

mediator extensions...2007-11-12 12:17:01,937 [127.0.0.1-pzfdell] [main] INFO SynapseInitializationModule

Initializing the Synapse configuration ...2007-11-12 12:17:01,968 [127.0.0.1-pzfdell] [main] INFO XMLConfigurationBuilder Generating

the Synapse configuration model by parsing the XML configuration (some deleted)2007-11-12 12:17:04,359 [127.0.0.1-pzfdell] [main] INFO HttpCoreNIOSender HTTP Sender

starting2007-11-12 12:17:04,968 [127.0.0.1-pzfdell] [main] INFO HttpCoreNIOListener HTTPS Listener

starting on port : 84432007-11-12 12:17:04,968 [127.0.0.1-pzfdell] [main] INFO ServerManager Starting transport

https on port 84432007-11-12 12:17:05,046 [127.0.0.1-pzfdell] [main] INFO ServerManager Ready for processing

History of the project• August 2005 Kicked off as an incubator

proposal• December 2005 Milestone 1 released• July 2006 Milestone 2 released• December 2006 Synapse 0.90 released• January 2007 Graduates from Incubator• May 2007 Released 1.0• December 2007 Becomes a Top Level

Project• January 2008 Synapse 1.1.1 released

A really simple exampleExposing an existing SOAP endpoint as

XML/HTTP, XML/JMS<definitions> <proxy name=“example" transports=“http jms"> <target> <endpoint> <wsdl uri=“http://remote.com/service?wsdl“ service=“RemoteService" port=“RemotePort"/> </endpoint> <outSequence> <send/>

</outSequence> </target> </proxy> </definitions>

Some other things you can do “out of the box”

• Content-based routing– Direct messages based on properties or XPath expressions

• Convert from existing formats (CSV, Fixed records, etc) to and from XML

• Transform XML – Using XSLT or XQuery

• Validate using XML Schema• Update databases and enhance messages with extra data

– DBLookup and DBReport mediators – any JDBC database• Switch between SOAP and non-SOAP, any transport

– HTTP, HTTPS, SMTP/POP3, XMPP, JMS, TCP, Filesystem, FTP, AMQP

• Add or handle WS-* support including– WS-Security, WS-SecureConversation, WS-Trust, WS-

ReliableMessaging• Load balancing, failover, throttling

Registries and Dynamism

Synapse “Registry”HTTP

extensible

readand cache

notify

“Transactional updates”-existing flows continue to use old config

Also graceful restart -switch off transport cleanly-restart Synapse when all work is done

A more detailed example

NY

VariableFormat records

London

Existingtrade

database

D2243578XX910D6233578YYYY9

<FEED> <CAK>2243578</CAK> <AccNo>3289019</AccNo> <CAT>AK</CAT> …</FEED>

WS-Security (encryptionand digital signature)

MQ

Validation

Overview of the flow<sequence name=“new york”> Flatpack with Variable record config E4X script to reformat XML

Send to London</sequence><sequence name=“london”>

DBreport Filter Send to MQ

</sequence>

Results• Replicated a 3 month project is 3 days

– Included enhancing the Flatpack mediator to support Variable Records

– Added WS-Security over original scenario– 1200 lines of config reduced to less than 300– Much more maintainable – clean separation of

concerns between departments

Google Spreadsheet and CSV

Google.com

CSV

Synapse

HttpPollerJob

CSV to XML Atom

Esper• Event Stream Processing project

– http://esper.codehaus.org

• Allows you to define queries on sets of “events”SELECT AVG(price) FROM

OrderEvent.WIN:TIME(30 sec)

• EsperMediator for Synapse makes it simple to add CEP to your SOA

Ganglia, Quartz, Esper

Synapse

QuartzScheduler

Gangliagmond

telnet 8649

<GANGLIA_XML>GMondPoller

Job

EsperMediator

SELECTAVG(CPU_USER)FROM GANGLIA

urn:gmond

Alertnotification

IMAtom

orJMS

urn:cpu

<definitions xmlns="http://ws.apache.org/ns/synapse"><task class="org.fremantle.gmond.GMonTask“ name=“Gmon”> <trigger interval="5000"/> <property name="hostname" value="localhost"/>

<property name="port" value="8649"/> <property name="to" value="urn:gmond"/> </task>

<in> <filter source="get-property('To')" regex="urn:gmond">

<log/> <class name="org.fremantle.esper.EsperMediator"> <property name="Configuration"

value=“./repository/conf/esper.conf.xml"/> <property name="statement"

value="select avg(cpu_user) from Ganglia.win:length_batch(10) "/> <property name="EventToAddress" value="urn:cpu"/> </class> </filter> <filter source="get-property('To')" regex="urn\:cpu">

<send> <endpoint>

<address uri="http://localhost:9090/notfication"/> </endpoint> </send> </filter> </in></definitions>

Performance

• Non-blocking IO– Apache HTTPCore – http://hc.apache.org/httpcomponents-cor

e/httpcore-nio/index.html

• Streaming XML and Binary– Apache Axiom– http://ws.apache.org/commons/axiom

Non-blocking graphically

Thread2

Incoming req

Socke

t open

Thread1Socke

t open

Requestprocessing

Responseprocessing

Outgoing resp

Outgoing req

Incoming resp

Synapse

This model means:1. Synapse threads never blocked during normal processing2. Number of sockets open >> number of threads

TIM

E

Demonstrating Performance• Synapse by default runs

– 2 listener threads– 2 sender threads– 8 worker threads

• Added a 100ms thread sleep to the server

• Ran 250 concurrent clients for 10000 runs– Simply would not have run without NIO

• Also did a simple test comparing:– 346 bytes in/ 1,170 bytes out– Direct to Axis2: 7.4ms– Via Synapse: 8.1ms – diff = 0.710ms!!

XSLT performance

Extending Synapse• Java Mediators

– Implement a simple Java API• Java Commands

– Pure POJO with mapping into messages using XPath• Scripts

– Using the Apache BSF project you can write scripts in JavaScript, Groovy and Ruby

• Synapse extensions– First class mediators with their own “Domain” XML configuration– Simply drop the JAR into the classpath

• Tasks– Repetitive jobs can be run at set intervals

• Registries– Synapse can dynamically load its configuration from a remote registry

• Transports– Create new connectors to remote systems

Simple Mediator: CSV->XMLpublic boolean mediate(MessageContext mc) {

DataHandler dh = PayloadHelper.getBinaryPayload(mc);BufferedReader br;new BufferedReader(new InputStreamReader(dh.getInputStream()));CSVReader csvReader = new CSVReader(br);

OMFactory fac = OMAbstractFactory.getOMFactory();OMElement el = fac.createOMElement("csv", csvNS);// create element to hold datawhile ((nextLine = csvReader.readNext()) != null) {

rownum++;// add elements to XML

}br.close();PayloadHelper.setXMLPayload(mc, el);return true;

}

Tasks – Quartz integration• Simple repetitive actions• Can also be used to start a long-running activity at

startup• Uses the Quartz Scheduler to run items

– www.opensymphony.com/quartz

• Tasks must implement the Task interfacepackage org.apache.synapse.startup;

public interface Task

{

public abstract void execute();

}

• Tasks may implement the ManagedLifecycle interface• Properties are set by injection (String and XML)

Sample task - MessageInjectorpublic class MessageInjector implements Task, ManagedLifecycle{

public void setTo(String url) { to = url; }public void setMessage(OMElement elem) { message = elem; }public void execute() { MessageContext mc =

synapseEnvironment.createMessageContext(); mc.setTo(new EndpointReference(to)); PayloadHelper.setXMLPayload(mc,

message.cloneOMElement());synapseEnvironment.injectMessage(mc);

}}

Script example<script language="js"><![CDATA[ var rowset = mc.getPayloadXML() var ns = new Namespace("http://..."); var d6 = rowset..ns::row.(@recordname=="D6"); var output = <FEEDS/> for (var i=0; i<d6.length(); i++) { var row = d6[i]; var cak = row.ns::entry.(@name==“CAK").text(); … var feed = <FEED> <CAK>{cak}</CAK> <AccNo>{accno}</AccNo> </FEED>; output.appendChild(feed); } mc.setPayloadXML(output); </script>

Community Site for extensionshttp://esbsite.org

Connectors, Adapters, Other projects

• CSV, Fixed and Variable records – FlatPack, OpenCSV

• FIX transport using QuickFix/J• AMQP transport using Apache QPid• Complex Event Processing based on Esper• Atom using Apache Abdera• Rules using Drools• EDI using Smooks• BPEL using Apache ODE• Hessian Binary XML using Hessian• URLRewriter • IM Mediator MSN, ICQ, Yahoo, Jabber

User quotes"Synapse's simplicity of configuration, ease of

extensibility, and integration were the key factors in our choice. Synapse's speed and stability, non-blocking I/O support, and responsive development community thensealed the decision,"

"Synapse passed all our performance benchmark, loadand memory leak tests with flying colours."

“Thanks for the quick fix. Synapse continues to rock.”

Futures• We continue to add new mediators and transports• Better support for complete HTTP Proxy

– Jointly done with HTTPCore• More work on a non-XML DSL for Synapse• Better support for REST

– DELETE and PUT support• Unifying support for events

– WS-Eventing, Atom, RSS, XMPP• Improved cluster management

– Graceful restart• Improved JMX management

– Better granularity

Getting Started

Getting Involved• Join us

– dev@synapse.apache.org– user@synapse.apache.org

• Raise a JIRA for an improvement you would like– http://issues.apache.org/jira/browse/SYNAPSE

• Submit a patch• Contribute a mediator or a task definition

Questions?