Do we need ESB any more?

Artur Karaźniewicz

About me

• Artur Karaźniewicz - Chief Integration And Solution Architect, Integration Team Leader - Allianz Poland

• Working with Java since 1999 (JServ anybody?)

• Experience in Financial Services

First things first, but not necessarily in that order. First things first, but not necessarily in that order. -- Doctor Who-- Doctor Who

What’s an ESB?

What’s an ESBEnterprise Service Bus - term first coined by Gartner around 2002 (although few others claim They coined the term before)

(Enterprise Service Bus) Universal integration backbone. An (Enterprise Service Bus) Universal integration backbone. An ESB acts as a shared messaging layer for connecting ESB acts as a shared messaging layer for connecting

applications and other services throughout an enterprise applications and other services throughout an enterprise computing infrastructure. It supplements its core computing infrastructure. It supplements its core

asynchronous asynchronous messaging backbonemessaging backbone with intelligent with intelligent transformation and routingtransformation and routing to ensure messages are passed to ensure messages are passed

reliably. Services participate in the ESB using either reliably. Services participate in the ESB using either web web servicesservices messaging standards or the Java Message System messaging standards or the Java Message System

(JMS).(JMS).

What’s an ESBSonic Software, one of the first ESB bandwagon members has it's own definition

An ESB is software infrastructure that simplifies the An ESB is software infrastructure that simplifies the integration and flexible reuse of business components using a integration and flexible reuse of business components using a

service-orientedservice-oriented architecture. An ESB makes it easy to architecture. An ESB makes it easy to dynamically connect, dynamically connect, mediatemediate and control services and their and control services and their

interactions.interactions.-- source -- source http://www.businessreviewonline.com/blog/archives/2005/12/does_sonics_esb.htmlhttp://www.businessreviewonline.com/blog/archives/2005/12/does_sonics_esb.html

What’s an ESBIONA has little bit different perception what ESB actually is

In general we agree with Sonic's requirements for an In general we agree with Sonic's requirements for an ESB, at a technical level when it comes to how to ESB, at a technical level when it comes to how to

meet those requirements we think they have got it meet those requirements we think they have got it all wrong. [...] Specifically, he said that Iona believes all wrong. [...] Specifically, he said that Iona believes

Sonic's ESB is "overly JMS [Java Message Service] Sonic's ESB is "overly JMS [Java Message Service] and broker based".and broker based".

-- source http://www.businessreviewonline.com/blog/archives/2005/12/does_sonics_esb.html-- source http://www.businessreviewonline.com/blog/archives/2005/12/does_sonics_esb.html

What’s an ESBPolarLake, another ESB Vendor adds another view

Great to see Sonic Software's definition converge Great to see Sonic Software's definition converge towards ours. In particular, they are correctly towards ours. In particular, they are correctly

identifying that identifying that mediationmediation - a term we have used for - a term we have used for quite some time - is the core feature of an ESB.quite some time - is the core feature of an ESB.

-- source -- source http://www.businessreviewonline.com/blog/archives/2005/12/does_sonics_esb.htmlhttp://www.businessreviewonline.com/blog/archives/2005/12/does_sonics_esb.html

Odd that we think definitions are definitive. Odd that we think definitions are definitive. -- Larry Wall, Perl Creator-- Larry Wall, Perl Creator

So what’s ESB after all?

So What’s an ESB, after all?

Messaging BackboneMessaging Backbone

Routing and mediationRouting and mediation

WS StackWS Stack Adapters/ConnectorsAdapters/Connectors

Legacy SystemsLegacy Systems

• A little bit of distribution mechanisms

• Bus Architecture vs. Hub And Spoke

• Strong monitoring and management capabilities

• With little pinch of flexibility...

So What’s an ESB, after all?

What ESB is not?• It’s not an Application Server!

• It’s not centralized nor monolithic

• It’s not BPMS (Business Process Management Suite)

• It’s not MOM

For every complex problem, there is a solution that is simple, For every complex problem, there is a solution that is simple, neat, and wrong.neat, and wrong.

-- Henry Louis Mencken -- Henry Louis Mencken

What’s wrong with ESB, then?

What’s wrong with ESB?

ESB

What’s wrong with ESB?

• It looks Great!..

• ...But in practice - most ESBs are typical 80/20 solutions (or simple, neat and wrong)

• 80% of (simple) things are very easy to implement using of the shelve ESB

• 20% of things are extremely difficult to implement using of the shelve ESB

We have 80% of Perl6 done and we are now working on the next 80%.We have 80% of Perl6 done and we are now working on the next 80%.-- Anonymous Coward, slashdot.org, Perl 6 discussion-- Anonymous Coward, slashdot.org, Perl 6 discussion

Examples?Excerpt from (some) ESB documentation

The Oracle Database adapter does not The Oracle Database adapter does not support the following data types: support the following data types: * PL/SQL TABLE * PL/SQL TABLE * TABLE * TABLE * VARRAY * VARRAY * OBJECT* OBJECTetc..etc..

Examples?Excerpt from (some) ESB documentation

The Oracle Database adapter accepts a The Oracle Database adapter accepts a character data for a NUMBER field character data for a NUMBER field without throwing an error. In the without throwing an error. In the database, the character is stored as 0.database, the character is stored as 0.

What’s wrong with ESB?

• Lack of sound community• “Community driven” vs. “consultants driven”

• Extremely proprietary solutions

• Proprietary extensions to standards

No standard or clause in a standard has a divine right of existenceNo standard or clause in a standard has a divine right of existence-- -- A Microsoft PKI architect explaining Microsoft's position on standards compliance.A Microsoft PKI architect explaining Microsoft's position on standards compliance.

What’s wrong with ESB?

• Focused on Vendor Background• Application Servers Vendors base their ESB on their

Application Servers

• EAI Vendors base ESB on their EAI

• Messaging Vendors base ESB on Message Brokers

• Some solutions became ESB for one night...

The trouble is that things The trouble is that things nevernever get better, they just stay the same, only more so. get better, they just stay the same, only more so.-- Terry Pratchett, "Eric" -- Terry Pratchett, "Eric"

Steve Vinoski, chief engineer of product innovation for IONA

Frankly, if I were an enterprise architect today, and I Frankly, if I were an enterprise architect today, and I were genuinely concerned about development costs, were genuinely concerned about development costs,

agility, and extensibility, I’d be looking to solve agility, and extensibility, I’d be looking to solve everything I possibly could with dynamic languages everything I possibly could with dynamic languages and REST, and specifically the HTTP variety of REST. and REST, and specifically the HTTP variety of REST. I’d avoid ESBs and the typical enterprise middleware I’d avoid ESBs and the typical enterprise middleware

frameworks unless I had a problem that really frameworks unless I had a problem that really required them (see below). I’d also try to totally required them (see below). I’d also try to totally

avoid SOAP and WS-*.avoid SOAP and WS-*.

What’s wrong with ESB?

The ESB check list• Contract first development• What does this mean

• Why it’s important?

• Agility• Test Driven Development

• Contiguous Integration

• “Mockability”

The ESB check list• Standard compliance• WS-* standards compliance (beware of Vendor’s bias!)

• Interoperability

• WS Stack standard compliance

• Flexibility• REST

• SOAP

• Sound Community

My opinions may have changed, but not the fact that I am right.My opinions may have changed, but not the fact that I am right. -- Ashleigh Brilliant -- Ashleigh Brilliant

CXF the ESB framework

What's CXF

• IONA Celtix + Codehouse XFire = CXF

Celtix Celtix isis an Open Source, Java an Open Source, Java Enterprise Service BusEnterprise Service Bus and hosted in the ObjectWeb community.and hosted in the ObjectWeb community.

-- http://www.iona.com, in 2006

While Celtix has traditionally called itself an ESB, if you While Celtix has traditionally called itself an ESB, if you look at the code you'll see that Celtix has primarily look at the code you'll see that Celtix has primarily

focused on providing JAX-WS and WS-* support. The focused on providing JAX-WS and WS-* support. The new project will new project will NOTNOT be branded as an be branded as an ESBESB..

-- http://xfire.codehaus.org/XFire+and+Celtix+Merge

What’s CXF?• JAX-WS certified stack

• Commercially Supported IONA

• Embeddable stack

• J2EE containers (BEA WLS, JBoss, IBM WebSphere, Tomcat, Oracle iAS, Apache Geronimo etc. )

• JBI (Apache Service Mix)

• Standalone Spring Container

What’s CXF?● WS-* compliant stack

● WS-Addressing,

● WS-Policy,

● WS-ReliableMessaging

● WS-Security

● Fully integrated with Spring● REST enabled framework through

JAX-RS and HTTP binding

CXF architecture

Messaging / InterceptorsMessaging / Interceptors

BusBus

Front-endsFront-ends

JAX-WSJAX-WS SimpleSimple

BindingsBindings

JAXBJAXB

AegisAegis

TransportsTransports

JMSJMS

HTTPHTTP

LocalLocal

JAX-WS Architecture

ToolingTooling

JAX-WSJAX-WS

JAXB 2JAXB 2 SAAJSAAJ

•JAX-WS – Java API for XML WS• JSR 224 (java.xml.soap)• Web Services metadata JSR 170 (java.jws)• ••

•JAXB Java XML Binding API• JSR 222 (java.xml.bind)• • ••

•Tooling•WSDL to Java•Java to WSDL•etc...• • ••

•SAAJ•SOAP with Attachments API for Java• • ••

CXF ArchitectureHow does CXF fit into ESB landscape?

Routing and mediationRouting and mediation

WS StackWS Stack Adapters/ConnectorsAdapters/Connectors

Messaging BackboneMessaging BackboneMessaging BackboneMessaging BackboneMessaging BackboneMessaging Backbone

CXFCXF

Seeing is believingSeeing is believing-- American Proverb -- American Proverb

Exposing Services

Hello World, CXF Way...

Hello World, CXF Way...

Hello World, CXF Way

• Look Ma! no XML, no generated artefacts!

• POJO service

• Dead simple! Even Your Grandma’ can do it!

• Up and running - in just 19 lines of code!

What’s Wrong with this Example?

• It’s not contract first

• It’s just remoting

• It runs in built-in HTTP container

Real-world CXF WebservicesShipIt Inc. - Shipping service The contract

Real-world CXF WebservicesShipIt Inc. - Shipping service The contract

Real-world CXF WebservicesGenerating the service model

Real-world CXF WebservicesGenerated POJO model

Real-world CXF WebservicesGenerated POJO model

Real-world CXF WebservicesService Endpoint Interface

Real-world CXF WebservicesImplementing the Endpoint

Real-world CXF WebservicesWiring it all together, and deploying

Real-world CXF Webservices

• What's wrong with this service?

• No value constructors

• No toString, hashCode and equals

● XMLGregorianCalendar?

● No validation

● No Security

Real-world CXF Webservices

• Customizing JAXB binding via xjc plugins

• Jakarta Commons Plugin

• Value Constructor Plugin

● Simple Preserve Plugin

● Value Constructor Plugin

● More on:

● https://jaxb2-commons.dev.java.net/

Real-world CXF Webservices• Getting rid of XMLGregorianCalendar

Real-world CXF WebservicesAdding validation and security

Real-world CXF WebservicesPutting it all together

Real-world CXF WebservicesPutting it all together

Real-world CXF WebservicesMonitoring and managing CXF● Built-in JMX monitoring and managing

module● Exposing custom components

Real-world CXF Webservices● Monitoring and managing CXF

There are only two tragedies in life: one is not getting what one There are only two tragedies in life: one is not getting what one wants, and the other is getting it.wants, and the other is getting it.

-- Oscar Wilde-- Oscar Wilde

Consuming Services

Consuming Services• Generate Stubs from WSDL, as before

• Use generated Client Stub

• Disadvantages

• No CXF fine-tuning

• Bloated client

• No Spring integration

Consuming WebservicesConsuming through CXF client API

The same in Spring

There are only two tragedies in life: one is not getting what one There are only two tragedies in life: one is not getting what one wants, and the other is getting it.wants, and the other is getting it.

-- Oscar Wilde-- Oscar Wilde

Testing Services

Testing services• Service implementation is just POJO

• Service can be exposed using Endpoint.publish and consumed as a standard endpoint

• Leads to problems with CI servers

• Services can be exposed through CXF convenient API, and through local:// (in VM) transport

Real-world CXF WebservicesUnit testing CXF services

Do we need ESB?• In complex scenarios... yes!

• But maybe You have one already?

• Check something that works for You

• Use ESB Check List when selecting concrete solution

• Try to avoid Vendor Lock-in

• Community is important!

Questions?

Dziękuję!