Do We Need Esb Any More


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Do We Need Esb Any More

  1. 1. Do we need ESB any more? Artur Karaźniewicz
  2. 2. 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
  3. 3. What’s an ESB? First things first, but not necessarily in that order. -- Doctor Who
  4. 4. What’s an ESB Enterprise 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 ESB acts as a shared messaging layer for connecting applications and other services throughout an enterprise computing infrastructure. It supplements its core asynchronous messaging backbone with intelligent transformation and routing to ensure messages are passed reliably. Services participate in the ESB using either web services messaging standards or the Java Message System (JMS).
  5. 5. What’s an ESB Sonic Software, one of the first ESB bandwagon members has it's own definition An ESB is software infrastructure that simplifies the integration and flexible reuse of business components using a service-oriented architecture. An ESB makes it easy to dynamically connect, mediate and control services and their interactions. -- source
  6. 6. What’s an ESB IONA has little bit different perception what ESB actually is In general we agree with Sonic's requirements for an ESB, at a technical level when it comes to how to meet those requirements we think they have got it all wrong. [...] Specifically, he said that Iona believes Sonic's ESB is "overly JMS [Java Message Service] and broker based". -- source
  7. 7. What’s an ESB PolarLake, another ESB Vendor adds another view Great to see Sonic Software's definition converge towards ours. In particular, they are correctly identifying that mediation - a term we have used for quite some time - is the core feature of an ESB. -- source
  8. 8. So what’s ESB after all? Odd that we think definitions are definitive. -- Larry Wall, Perl Creator
  9. 9. So What’s an ESB, after all? WS Stack Adapters/Connectors Routing and mediation Messaging Backbone Legacy Systems
  10. 10. So What’s an ESB, after all? • A little bit of distribution mechanisms • Bus Architecture vs. Hub And Spoke • Strong monitoring and management capabilities • With little pinch of flexibility...
  11. 11. 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
  12. 12. What’s wrong with ESB, then? For every complex problem, there is a solution that is simple, neat, and wrong. -- Henry Louis Mencken
  13. 13. What’s wrong with ESB? ESB
  14. 14. 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%. -- Anonymous Coward,, Perl 6 discussion
  15. 15. Examples? Excerpt from (some) ESB documentation The Oracle Database adapter does not support the following data types: * PL/SQL TABLE * TABLE * VARRAY * OBJECT etc..
  16. 16. Examples? Excerpt from (some) ESB documentation The Oracle Database adapter accepts a character data for a NUMBER field without throwing an error. In the database, the character is stored as 0.
  17. 17. 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 existence -- A Microsoft PKI architect explaining Microsoft's position on standards compliance.
  18. 18. 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 never get better, they just stay the same, only more so. -- Terry Pratchett, "Eric"
  19. 19. What’s wrong with ESB? Steve Vinoski, chief engineer of product innovation for IONA Frankly, if I were an enterprise architect today, and I were genuinely concerned about development costs, agility, and extensibility, I’d be looking to solve everything I possibly could with dynamic languages and REST, and specifically the HTTP variety of REST. I’d avoid ESBs and the typical enterprise middleware frameworks unless I had a problem that really required them (see below). I’d also try to totally avoid SOAP and WS-*.
  20. 20. The ESB check list • Contract first development • What does this mean • Why it’s important? • Agility • Test Driven Development • Contiguous Integration • “Mockability”
  21. 21. The ESB check list • Standard compliance • WS-* standards compliance (beware of Vendor’s bias!) • Interoperability • WS Stack standard compliance • Flexibility • REST • SOAP • Sound Community
  22. 22. CXF the ESB framework My opinions may have changed, but not the fact that I am right. -- Ashleigh Brilliant
  23. 23. What's CXF • IONA Celtix + Codehouse XFire = CXF Celtix is an Open Source, Java Enterprise Service Bus and hosted in the ObjectWeb community. --, in 2006 While Celtix has traditionally called itself an ESB, if you look at the code you'll see that Celtix has primarily focused on providing JAX-WS and WS-* support. The new project will NOT be branded as an ESB. --
  24. 24. 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
  25. 25. 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
  26. 26. CXF architecture Transports Front-ends Bindings JMS JAX-WS Simple JAXB HTTP Aegis Local Bus Messaging / Interceptors
  27. 27. JAX-WS Architecture •JAX-WS – Java API for XML WS JAXB 2 SAAJ • JSR 224 (java.xml.soap) • Web Services metadata JSR 170 (java.jws) ••JAXB Java XML Binding API JAX-WS •• JSR 222 (java.xml.bind) ••••Tooling • •WSDL to Java • •Java to WSDL Tooling •etc... • •SAAJ • • •SOAP with Attachments API for • Java • • •
  28. 28. CXF Architecture How does CXF fit into ESB landscape? WS Stack Adapters/Connectors CXF Routing and mediation Messaging Backbone
  29. 29. Exposing Services Seeing is believing -- American Proverb
  30. 30. Hello World, CXF Way...
  31. 31. Hello World, CXF Way...
  32. 32. 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!
  33. 33. What’s Wrong with this Example? • It’s not contract first • It’s just remoting • It runs in built-in HTTP container
  34. 34. Real-world CXF Webservices ShipIt Inc. - Shipping service The contract
  35. 35. Real-world CXF Webservices ShipIt Inc. - Shipping service The contract
  36. 36. Real-world CXF Webservices Generating the service model
  37. 37. Real-world CXF Webservices Generated POJO model
  38. 38. Real-world CXF Webservices Generated POJO model
  39. 39. Real-world CXF Webservices Service Endpoint Interface
  40. 40. Real-world CXF Webservices Implementing the Endpoint
  41. 41. Real-world CXF Webservices Wiring it all together, and deploying
  42. 42. Real-world CXF Webservices • What's wrong with this service? • No value constructors • No toString, hashCode and equals ● XMLGregorianCalendar? ● No validation ● No Security
  43. 43. Real-world CXF Webservices • Customizing JAXB binding via xjc plugins • Jakarta Commons Plugin • Value Constructor Plugin ● Simple Preserve Plugin ● Value Constructor Plugin ● More on: ●
  44. 44. Real-world CXF Webservices • Getting rid of XMLGregorianCalendar
  45. 45. Real-world CXF Webservices Adding validation and security
  46. 46. Real-world CXF Webservices Putting it all together
  47. 47. Real-world CXF Webservices Putting it all together
  48. 48. Real-world CXF Webservices Monitoring and managing CXF ● Built-in JMX monitoring and managing module ● Exposing custom components
  49. 49. Real-world CXF Webservices ● Monitoring and managing CXF
  50. 50. Consuming Services There are only two tragedies in life: one is not getting what one wants, and the other is getting it. -- Oscar Wilde
  51. 51. Consuming Services • Generate Stubs from WSDL, as before • Use generated Client Stub • Disadvantages • No CXF fine-tuning • Bloated client • No Spring integration
  52. 52. Consuming Webservices Consuming through CXF client API The same in Spring
  53. 53. Testing Services There are only two tragedies in life: one is not getting what one wants, and the other is getting it. -- Oscar Wilde
  54. 54. 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
  55. 55. Real-world CXF Webservices Unit testing CXF services
  56. 56. 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!
  57. 57. Questions?
  58. 58. Dziękuję!