My Notes - SOA for Dummies Part 3

PART II - Nitty – Gritty SOA

Chapter 4: SOA Sophistication – Pieces of SOA

-          ESB – Enterprise Service Bus is a communication channel for all SOA services.  One SOA Service sends messages and receives messages to and from other SOA services.  All this is done using ESB.  It’s an end-to-end communication. 

-          SOA Registry – It is an electronic catalogue for all services.  It maintains operational information about services to call each other and metadata information, what that service is all about input/output messages, which can be used programmers.  Important function of registry is to publish services, to make it available for its consumers.

-          BPM – Business process modelling is an end-to-end solution.  This is a more like configuration, where we can specify to carry out specific business functions which different business processes will interact.  End-to-end business processes a.k.a. workflow.

-          Service Broker – This is a runtime component, for BPM, which can actually find services and connect for a business process.

-          SOA Supervisor – Just monitors all processes by using reports generated by monitor agents (these are initialized by service brokers), this enables SOA supervisor to know current state of processes.  This is just like traffic police to make sure everything flowing smoothly.

-          SOA Plumbing – These are adapters which sit in between existing legacy code and bus

BPM Tool

-          Important functions

o   Creates Business functions

o   Links in Individual functions to Business applications.  Also links Business apps together

o   (publishes) adds and refers services registered in SOA Registry

o   Programs for workflow engine.

- Availability of services at all levels should be 99.999%

My Notes - SOA for Dummies Part 2

Chapter 3

-          This is generic information so far

-          Starting with Components, and code reusability, how it can be done, how it was restricted to individual developers, customers, applications.  When such components tried to interact had issues of interoperability

-          When internet started it was just static pages, as it evolved specifications and protocol developed around technological aspect HTML, XML, Browsers.  This further extended to use such component based systems to interact over Internet. 

-          This gave birth to webservices which posed challenges over connectivity and sharing data, where XML, WSDL and SOAP protocols were developed as standards

-          As webservices are used more by business, all such business process confined in one boundary earlier, there was need of making such processes accessible online thru internet.  Such that it can be accessed by other businesses.

-          Business Processes:

o   For any business there are set of processes and sub-processes are required to carry out to carry out day to day business functions.   Generally it may need manual intervention and application systems.  Stringing together such function of a business function is called business process. And SOA can do such stringing activity of manual functions and application functions and the process management to carry out business process.

o   From SOA perspective, business processes includes people, those business process itself, implemented as software applications, adapters, and process management.

-          Siloed Applications

o   Existing applications when added with some more components are called as composite applications.

o   Such composite applications (e.g. for one business department) interact with other composite applications interacts directly.  But this interaction can be costly in terms of resources; SOA facilitates such integration with some process management.  However integration is most difficult and crucial part for successful SOA implementation.

o   Application silos are applications which are constrained for individual business departments or functions.  Are not built for use by other business functions.  Such systems have two issues inconsistent data definitions and process duplication.

-          How SOA helps?

o   SOA just work with these application silos as it is, avoiding manual work required to talk to different silos. 

o   SOA can be done in steps, no need to do all at once and hence no wastage in earlier investments.