Web Oriented Architecture (reloaded) Emiliano Pecis Technology Business Unit

Wake Up, Neo. SOA has you…

Wake Up, Neo. SOA has you…

Red or Blue pill? WOA SOA

Agenda

WOA & SOA

<Insert Picture Here> “ In other words, the Web model provides a single, open, and unified information architecture that is consistent, easily consumed, extremely scalable, securable, very reusable, resilient, and highly federated.” Dion Hinchcliffe Founder, Hinchcliffe & Co. Dion Hinchcliffe’s Blog

WOA – Web Oriented Architecture

WOA & SOA

WOA versus SOA: not a competition

The elements of WOA

Make it simple with mashups

WOA – All About Resources

WOA and low case semantic web

ReST vs SOAP

Introducing REST Nouns: All resources, or nouns, are network-addressable with a global URL. Resources have “href” references to other related resources. The only way to address a resource is with a URL. Verbs: A common set of verbs are used to access all resources. The HTTP methods GET, PUT, POST, and DELETE map to retrieve, update, create, and delete (CRUD) functions. Representations: A resource might be represented as XML, JSON, HTML, text, image, and so on. Instantiating representation from or to the resource is handled on the server. A client can pick its preferred representation via a URI parameter or the “Accept:” header.

Nouns: All resources, or nouns, are network-addressable with a global URL. Resources have “href” references to other related resources. The only way to address a resource is with a URL.

Verbs: A common set of verbs are used to access all resources. The HTTP methods GET, PUT, POST, and DELETE map to retrieve, update, create, and delete (CRUD) functions.

Representations: A resource might be represented as XML, JSON, HTML, text, image, and so on. Instantiating representation from or to the resource is handled on the server. A client can pick its preferred representation via a URI parameter or the “Accept:” header.

REST Patterns 1/2 Give every “thing” an ID (URI): http://example.com/orders/2007/11 Link things together (Hypermedia links): <order self='http://example.com/customers/1234' > <amount>23</amount> <product ref='http://example.com/products/4554' /> <customer ref='http://example.com/customers/1234' /> </order> Use standard methods (HTTP verbs) GET is safe and idempotent PUT and DELETE are not safe but are idempotent POST is neither safe nor idempotent

Give every “thing” an ID (URI):

http://example.com/orders/2007/11

Link things together (Hypermedia links):

<order self='http://example.com/customers/1234' > <amount>23</amount> <product ref='http://example.com/products/4554' /> <customer ref='http://example.com/customers/1234' /> </order>

Use standard methods (HTTP verbs)

GET is safe and idempotent

PUT and DELETE are not safe but are idempotent

POST is neither safe nor idempotent

REST Patterns 2/2 Resources with multiple representations GET /customers/1234 HTTP/1.1 Host: example.com Accept: application/vnd.mycompany.customer+xml GET /customers/1234 HTTP/1.1 Host: example.com Accept: text/x-vcard Communicate statelessly Cookies shouldn’t be used to encode information that can be transferred by other, more standardized means

Resources with multiple representations

GET /customers/1234 HTTP/1.1 Host: example.com Accept: application/vnd.mycompany.customer+xml

GET /customers/1234 HTTP/1.1 Host: example.com Accept: text/x-vcard

Communicate statelessly

Cookies shouldn’t be used to encode information that can be transferred by other, more standardized means

REST Anti Patterns Tunneling everything through GET or POST http://example.com/some-api?method=deleteCustomer&id=1234 Resources are not identified by URIs; rather, URIs are used to encode operations and their parameters The HTTP method does not necessarily match the semantics Such links are usually not intended to be bookmarked There is a risk that “crawlers” (e.g. from search engines such as Google) cause unintended side effects Ignoring caching Cache-control: no-cache (always) Ignoring status code Misusing of 200 or 500 status code

Tunneling everything through GET or POST

http://example.com/some-api?method=deleteCustomer&id=1234

Resources are not identified by URIs; rather, URIs are used to encode operations and their parameters

The HTTP method does not necessarily match the semantics

Such links are usually not intended to be bookmarked

There is a risk that “crawlers” (e.g. from search engines such as Google) cause unintended side effects

Ignoring caching

Cache-control: no-cache (always)

Ignoring status code

Misusing of 200 or 500 status code

Processes and Resources

REST API

Sponsored Slide: WLP is REST enabled

Developing a scalable WOA

WOA and (server side) scalability

The need of a Datagrid Data grid brokers Data Supply with Data Demand Scale out Data Grid in middle tier using commodity hardware Application Servers Web Servers Ever Expanding Universe of Users Data Sources Data Demand Java Objects 10110001011001011101100101100101110001110 101100010110010111011001011001011100011101111110001110

Data grid brokers Data Supply with Data Demand

Scale out Data Grid in middle tier using commodity hardware

What is a datagrid? Caching Applications request data from the Data Grid rather than backend data sources Analytics Applications ask the Data Grid questions from simple queries to advanced scenario modeling Transactions Data Grid acts as a transactional System of Record, hosting data and business logic Events Automated processing based on event

How does it work? Data spread and backed up across Members Transparent to developer Members have access to all Data All Data locations are known – no lookup & no registry!

Data spread and backed up across Members

Transparent to developer

Members have access to all Data

All Data locations are known – no lookup & no registry!

Synchronous Update Avoids potential Data Loss & Corruption Predictable Performance Backup Partitions are partitioned away from Primaries for resilience No engineering requirement to setup Primaries or Backups Automatically and Dynamically Managed Write-behind How does it work?

Synchronous Update

Avoids potential Data Loss & Corruption

Predictable Performance

Backup Partitions are partitioned away from Primaries for resilience

No engineering requirement to setup Primaries or Backups

Automatically and Dynamically Managed

Write-behind

Membership changes (new members added or members leaving) Other members, using consensus , recover and repartition automatically No in-flight operations lost, no availability gap! Some latencies (due to higher priority of asynchronous recovery) Information Reliability & Continuous Availability are the priorities How does it work?

Membership changes (new members added or members leaving)

Other members, using consensus , recover and repartition automatically

No in-flight operations lost, no availability gap!

Some latencies (due to higher priority of asynchronous recovery)

Information Reliability & Continuous Availability are the priorities

Sponsored Slide: Oracle Coherence Implements Map interface Implements JCache interface Real-time filterable (bean) events Filters completely extensible Processors applied in parallel (grid) A large range of filters out-of-the-box Implements listeners

Implements Map interface

Implements JCache interface

Real-time filterable (bean) events

Filters completely extensible

Processors applied in parallel (grid)

A large range of filters out-of-the-box

Implements listeners

WOA actors Client side Server side

Client side

Server side

WOA actors #1: AJAX Asynchronous JavaScript and XML Combination: XMLHttpRequest, xml, dom, html, json Enables the partial page refresh feature

Asynchronous JavaScript and XML

Combination: XMLHttpRequest, xml, dom, html, json

Enables the partial page refresh feature

WOA actors #2: JS frameworks More high level than pure javascript Examples: dojo, scriptaculous, prototype, jquery, mooTools, yui A lot of stuff done, just invoke it! Ready for ajax and json

More high level than pure javascript

Examples: dojo, scriptaculous, prototype, jquery, mooTools, yui

A lot of stuff done, just invoke it!

Ready for ajax and json

WOA actors #3: Json J ava S cript O bject N otation More light than XML (data with less structures) Directly interpretrated by javascript No effort for creating / (de) serializing a tree dom Tens folders more fast More simple to traverse and get attributes

J ava S cript O bject N otation

More light than XML (data with less structures)

Directly interpretrated by javascript

No effort for creating / (de) serializing a tree dom

Tens folders more fast

More simple to traverse and get attributes

WOA developers love… Agile MVC framework like Grails Complete lightweight container like Spring Lightweight application server ORM like Toplink or Hibernate Data cache layer like Coherence or ehcache

Agile MVC framework like Grails

Complete lightweight container like Spring

Lightweight application server

ORM like Toplink or Hibernate

Data cache layer like Coherence or ehcache

Sponsored Slide: Weblogic Suite Startup the container with just a web profile (no ejb, no rmi, no jca, no jms) Weblogic Server supports Spring with a dedicated console Weblogic Server uses Toplink as ORM Weblogic Suite includes Oracle Coherence for the datagrid Coherence*Web is used to manage sessions in a datagrid fashion and to cache WLP objects

Startup the container with just a web profile (no ejb, no rmi, no jca, no jms)

Weblogic Server supports Spring with a dedicated console

Weblogic Server uses Toplink as ORM

Weblogic Suite includes Oracle Coherence for the datagrid

Coherence*Web is used to manage sessions in a datagrid fashion and to cache WLP objects

Scaling a SOA with the Datagrid

What does the scalable architecture need to ensure Avoid processing where possible Avoid I/O where possible Avoid serialization and de-serialization Avoid sending large documents over network Avoid distributed file schemes as your app scales up Avoid driving increasing traffic to backend systems Architect for performance from the beginning aka not throwing hardware at the problem!

Avoid processing where possible

Avoid I/O where possible

Avoid serialization and de-serialization

Avoid sending large documents over network

Avoid distributed file schemes as your app scales up

Avoid driving increasing traffic to backend systems

Architect for performance from the beginning aka not throwing hardware at the problem!

Data Grid for SOA Services Benefits Up to10 fold reduction in latency times used Cached data Cache available to other nodes in the cluster. Data grid provides backup of cache to peer nodes Cache can be persisted to the database using a number of mechanisms. Service Bus Portal Orchestration Engine Service Provider [data item] [data item] Service MySelfServPortal Coherence Grid Near Cache Cache This is a very large piece of customer data that has to be obtained in one go from the system.

Benefits

Up to10 fold reduction in latency times used Cached data

Cache available to other nodes in the cluster.

Data grid provides backup of cache to peer nodes

Cache can be persisted to the database using a number of mechanisms.

Restifying and caching a SOA Problem Siebel CRM works properly, but doesn’t scale as expected Challenges Customer requires rapid access to accurate information All data must be available for a Social CRM Mashup Customer wants to cache better the most frequently invoked services Solution (*) Implement a solution that is able to restify and cache all needed WS-SOAP exposed by Siebel (*) Custom solution, it’s not a product: just for demo purpose

Problem

Siebel CRM works properly, but doesn’t scale as expected

Challenges

Customer requires rapid access to accurate information

All data must be available for a Social CRM Mashup

Customer wants to cache better the most frequently invoked services

Solution (*)

Implement a solution that is able to restify and cache all needed WS-SOAP exposed by Siebel

(*) Custom solution, it’s not a product: just for demo purpose

Restifying and caching a SOA

RSD: parse the URL http://siebel.com/rsd/catalog/product/id/5461 ?n1=v1&n2=v2… get / put / post / delete

RSD: check if cached Check the cache only if GET method has been used Assign a XML payload to a variable Send the payload to Coherence through the OSB Transport if Coherence is not UP a WS call will be done If the item is not in the cache a WS call will be done) Skipcache variable will be tested to decide if it is the case to return the cached value or invoke the WS

RSD: check if cached Check the cache only if GET method has been used Assign a XML payload to a variable Send the payload to Coherence through the OSB Transport if Coherence is not UP a WS call will be done If the item is not in the cache a WS call will be done) Skipcache variable will be tested to decide if it is the case to return the cached value or invoke the WS

RSD: check if cached Check the cache only if GET method has been used Assign a XML payload to a variable Send the payload to Coherence through the OSB Transport if Coherence is not UP a WS call will be done If the item is not in the cache a WS call will be done) Skipcache variable will be tested to decide if it is the case to return the cached value or invoke the WS

RSD: the configuration file GET /rsd/catalog/categories/id/3473 The following URI parts select the needed WS parts: This is the SOAP operation to invoke This is the SOAP payload to load This is the SOAP response to return But, what about the URL parameters?

RSD: the configuration file GET /rsd/catalog/categories/id/3473

RSD: check if cached Check the cache only if GET method has been used Assign a XML payload to a variable Send the payload to Coherence through the OSB Transport if Coherence is not UP a WS call will be done If the item is not in the cache a WS call will be done) Skipcache variable will be tested to decide if it is the case to return the cached value or invoke the WS

RSD: check if cached Check the cache only if GET method has been used Assign a XML payload to a variable Send the payload to Coherence through the OSB Transport if Coherence is not UP a WS call will be done If the item is not in the cache a WS call will be done) Skipcache variable will be tested to decide if it is the case to return the cached value or invoke the WS

P B Backup Node Primary Node Get / Put (Cachekey) Service Data Coherence Data Grid OSB Result Cache Oracle Service Bus 1. check cache 2. if results not in cache, invoke service & cache results Resource SOAP/XML REST/JSON Oracle Weblogic Portal Other Portals Siebel WCM Wiki Blog Forum … Any Web Services Client /browser

Siebel

WCM

Wiki

Blog

Forum

…

Restful Datagrid Reasonings In REST each resource has a unique URL This URL is the primary key for the Datagrid (Coherence) The cached value is stored in JSON format to be as “client ready” as possible REST and JSON give developers more flexibility, ensuring a strong light-matter coupling between content and its rapresentation Javascript frameworks, like Jquery, allows developers to get JSON data from the datagrid and manipulate them as they prefer

In REST each resource has a unique URL

This URL is the primary key for the Datagrid (Coherence)

The cached value is stored in JSON format to be as “client ready” as possible

REST and JSON give developers more flexibility, ensuring a strong light-matter coupling between content and its rapresentation

Javascript frameworks, like Jquery, allows developers to get JSON data from the datagrid and manipulate them as they prefer

Q&A