Sftware as a Service Hajie Hang Oghenev Dibie
Executive Summary In this presentatin, we g thrugh the Sftware as a Service Methdlgy, examine its benefits and drawbacks and talk abut tw state-f-art SaaS systems Amazn Web Service and Ggle App Engine We als lk int Service Oriented Architecture pwering SaaS applicatins and its impact n mdern web 2.0 applicatins Finally, we examine hybrids f traditinal and SaaS applicatins
What is Sftware as a Service (SaaS) Backgrund Brief histry Cncept Big picture Related terms Cmputing Tday SasS is everywhere The SaaS Market Benefits f SaaS Drawbacks f SaaS Rbustness Privacy Security Reliability Service Oriented Architectures (SOA) Guiding principles f SOA Case studies Amazn Web Services (AWS) Ggle App Engine Overview Influence f SOA n Web 2.0 develpment Zend Framewrk Hybrids f Traditinal and SaaS applicatins Drpbx Micrsft Office Summary References
What is SaaS? Definitin: Sftware as a Service (SaaS), a.k.a. ndemand sftware, is a sftware delivery mdel in which sftware and its assciated data are hsted centrally and accessed using a thin-client, usually a web brwser ver the internet. Wikipedia Simply put, SaaS is a methd fr delivering sftware that prvides remte access t sftware as a webbased service. The sftware service can be purchased with a mnthly fee and pay as yu g.
What is SaaS? Where des the term SaaS cme frm? The SAAS acrnym allegedly first appeared in an article called "Strategic Backgrunder: Sftware As A Service", internally published in February 2001 by the Sftware & Infrmatin Industry s ebusiness Divisin Multi-tenant architecture Virtualizatin as a alternative Pricing mdel pay as we g, relatively lw cst fr user prvisining Cnfiguratin and custmizatin Easy fr applicatin custmizatin Accelerated feature delivery It means a much shrter release cycle Open integratin prtcls Typically based n HTTP, JSON,REST, SOAP
An example Imagine yu are the funder f a start-up cmpany and yu need t deal with tns f new custmers Buying a full versin Custmer Relatinship Management (CRM) Sftware is expensive With SaaS, yu can buy a web-based CRM sftware that is pay as yu g and scales t demand! Benefits: Save mney n sftware license, cut cst n maintenance, and hardware purchase. Cmbined with lwer start-up cst and a faster return n investment!
A Brief Histry In 1960s, IBM and ther mainframe prviders cnducted time-sharing r utility cmputing services, ffering cmputer pwer and database t banks and large rganizatin In 1990s with the expansin f Internet, Applicatin Service Prviders (ASP) appeared. They prvided small businesses with the service f hsting and managing specialized business applicatin Starting frm 2003, the true SaaS became ppular due t the increased speed f internet cnnectins. Ultimately, all sftware will be webbased and pay-as-g
This diagrams shws the evlutin f the Sftware as a Service and its ecsystem
Cncept The idea f using sftware as a service first ppped up in the late 1990s in rder t allw sharing enduser licenses in a way that reduced cst and als shifted infrastructure demands frm the cmpany t the sftware prvider. Des it merely save n the license cst? And mre: upgrading, maintenance, hardware
The Big Picture Sftware as a Service is lcated in the applicatin level f the stack
Related Terminlgy Clud cmputing Clud cmputing is the delivery f cmputing as a service rather than a prduct, whereby shared resurces, sftware, and infrmatin are prvided t cmputers and ther devices as a utility ver a netwrk Platfrm as a Service Platfrm as a service (PaaS) is a categry f clud cmputing services that prvide a cmputing platfrm and a slutin stack as a service. Infrastructure as a Service Infrastructure as a Service is a prvisin mdel in which an rganizatin utsurces the equipment used t supprt peratins, including strage, hardware, servers and netwrking cmpnents. The service prvider wns the equipment and is respnsible fr husing, running and maintaining it. Multi-Tenancy Multi-Tenancy refers t a principle in sftware architecture where a single instance f the sftware runs n a server, serving multiple client rganizatins Applicatin Service Prvider prvided businesses with the service f hsting and managing specialized business applicatins, with the gal f reducing csts thrugh central administratin and thrugh the slutin prvider's specializatin in a particular business applicatin
Sme key differences Cluding cmputing is the big applicatin cntext (umbrella) cvering SaaS and ther related terms as a Service are the buzz wrds used t specify varius applicatin scenaris. E.g. Strage as a Service is an umbrella fr SaaS applicatins that prvide clud strage. PaaS deals with whle cmputing platfrms prvided as a service such as perating system envirmnets E.g. Ggle Chrme OS running n Ggle ChrmeBks IaaS aims t prvide the whle cmputing pwer (cmputer clusters) fr the applicatin dmain s we dn t have t wrry abut the physical machines and hw they are deplyed
Cmputing Tday We are in the era f Clud Cmputing! Clud cmputing stack Infrastructure as a Service (IaaS) Platfrm as a Service (PaaS) Sftware as a Service (SaaS) Mnitring as a Service (MaaS) - emerging Cmmunicatin as a Service (CaaS) Anything as a Service emerging S many buzz terms...but SaaS is ne f the mst widely used service mdel
SaaS is everywhere
The SaaS market SaaS sales in 2010 reached $10billin In 2011, its sales is up 20.7% frm 2010 SaaS revenue will be mre than duble its 2010 numbers by 2015 and reach a prjected $21.3 Business SaaS is the majr market Custmer Relatinship Management (CRM) is the largest market with 18.8% annually grwth wrldwide
Business s perspective SaaS has a lt f appeal t businesses. Here are a few reasns why: Multi-tenant sftware architecture Lw cst, fast investment, shared license High manageability Free f deplyment and supprt Cst-effective: pay as we g Custmizatin is easy Can scale well cmmercializatin
Advantages f SaaS Easy t use Mst SaaS applicatins d nt require mre than a web brwser t run Cheap- The pay as yu g pricing mdel f SaaS makes it affrdable t small businesses and individuals. Scalability: SaaS applicatin can be easily scaled up r dwn t meet cnsumer demand. Cnsumers d nt need t wrry abut additinal cmputing infrastructure t scale up. Applicatins are less prne t data lss since data is being stred in the clud. Cmpared t traditinal applicatins, SaaS applicatins are less clunky. They d nt require users t install/uninstall binary cde n their machines Due t the delivery nature f Sass thrugh the internet, SaaS applicatins are able t run n a wide variety f devices. Allws fr better cllabratin between teams since the data is stred in a central lcatin. Velcity f change in SaaS applicatins is much faster. SaaS favrs a Agile develpment life cycle. Sftware changes and frequent and n-demand. Mst Saas services are updated abut every 2 weeks and users are mst time unaware f these changes.
Drawbacks f SaaS Rbustness: SaaS sftware may nt be as rbust (functinality wise) as traditinal sftware applicatins due t brwser limitatins. Cnsider Ggle Dc & Micrsft Office. Privacy Having all f a user s data sit in the clud raises security & privacy cncerns. SaaS prviders are usually the target f hack explits e.g. Ggle servers have been the target f explits purprtedly frm China in the last several years Security Attack detectin, malicius cde detectin Reliability: In the rare event f a SaaS prvider ging dwn, a wide range f dependent clients culd be affected. Fr example, when Amazn EC2 service went dwn in April 2011, it tk dwn FurSquare, Reddit, Qura and ther well knwn applicatins that run n it. We shall discuss each f these issues in mre details in the next sectin
Rbustness SaaS applicatins may nt be able t prvide the same level f functinality as traditinal applicatins. This is partly due t current limitatins f the web brwser. Cnsider Ggle dc and Micrsft Office Mst SaaS applicatins are intlerant t slw internet cnnectins and this can lead t erratic behavir Ggle dc may nt be synchrnized well between teams in a lw internet cnnectin
Privacy Lts f issues arise with sensitive data stred in the clud. Cmmn privacy questins include: Wh has the access t the data? Hw t distribute the rights? What type f data can be saved n the clud, and lcally? What abut the cnfidential data? Dn t we really have t wrry abut data sharing? Wh is viewing ur data, mdifying the data, and re-distributing ur data? With r withut permissin? Data sharing between private and public cluds
Security SaaS applicatins are prne t attack because everything is sent ver the internet Data encryptin and decryptin Cmmunicatin prtcls Virtualizatin versus Multi-tenant architecture: which ne is better in terms f the security? Transactin prcessing, netwrking issues
Reliability Althugh mst SaaS applicatins are highly reliable, dwn time is still inevitable and can be very expensive cmmercial SaaS sftware The applicatin, data, backups, everything are in the clud, thus making it hard t recver frm the server dwn time. Yu dn t physically wn the cde, they are in the clud
Service- Oriented Architecture SaaS is the methdlgy fr prviding cmputing service ver the Internet SOA is the sftware architecture that pwers SaaS applicatin One f the mst cmmnly seen practices fr SaaS and clud cmputing Definitin: a set f principles and methdlgies fr designing and develping sftware in the frm f interperable services It prvides a way fr cnsumers f services, such as web-based applicatins t be aware f available SOA-based services.
The diagram abve shws the rle f SOA in SaaS
Guiding Principles f SOA Standardized service cntract Services adhere t a cmmunicatins agreement, as defined cllectively by ne r mre servicedescriptin dcuments Service abstractin Beynd descriptins in the service cntract, services hide lgic frm the utside wrld. Service lse cupling Services maintain a relatinship that minimizes dependencies and nly requires that they maintain an awareness f each ther. Service autnmy Services have cntrl ver the lgic they encapsulate. Service reusability Lgic is divided int services with the intentin f prmting reuse. Service granularity A design cnsideratin t prvide ptimal scpe and right granular level f the business functinality in a service peratin. Service statelessness Services minimize resurce cnsumptin by deferring the management f state infrmatin when necessary Service cmpsability Services are effective cmpsitin participants, regardless f the size and cmplexity f the cmpsitin.
Cmmnly- used Prtcls JSON XML SOAP ATOM The JSON frmat is ften used fr serializing and transmitting structured data ver a netwrk cnnectin. It is used primarily t transmit data between a server and web applicatin, serving as an alternative t XML The design gals f XML emphasize simplicity, generality, and usability ver the Internet. It is a textual data frmat with strng supprt via Unicde fr the languages f the wrld. Althugh the design f XML fcuses n dcuments, it is widely used fr the representatin f arbitrary data structures, fr example in web services riginally defined as Simple Object Access Prtcl, is a prtcl specificatin fr exchanging structured infrmatin in the implementatin f Web Services in cmputer netwrks The name Atm applies t a pair f related standards. The Atm Syndicatin Frmat is an XML language used fr web feeds, while the Atm Publishing Prtcl is a simple HTTP-based prtcl fr creating and updating web resurces
SaSS case studies We wuld nw cnsider the services prvided by tw f the biggest SaaS prviders tday: Amazn & Ggle. We lk int the categries f their SaaS fferings and hw they imprve mdern applicatin develpment & deplyment.
Amazn Web Services(AWS) Beginning in 2006, Amazn web services prvides a wide range f services and slutins fr pwering applicatins. They fall under the fllwing categries: Strage Amazn simple strage services(s3) Amazn Elastic Bk Stre(EBS) Netwrking Amazn Virtual Private Clud (VPC) Amazn Rute53 Database Amazn Dynam DB Amazn Relatinal Database Service (RDS) Cmpute Amazn Elastic Clud Cmpute (EC2) Amazn Elastic Map Reduce (EMR)
AWS: Cmpute Amazn s cmpute web services prvide users with raw cmputatin pwer t meet applicatin needs and scale accrdingly. AWS have tw cre web services fr cmputatin. Amazn Elastic Clud Cmpute (Amazn EC 2) Amazn EC2 web service allws fr resizable cmpute capacity in the clud. With Amazn EC2, develpers are able t easily scale their cmputatin needs up r dwn t meet demand.
AWS: Cmpute Amazn Elastic Map Reduce Amazn Elastic Map Reduce (EMR) prvides develpers and researchers with cmpute pwer fr prcessing data intensive tasks. It is based n Apache s Hadp framewrk. As with EC2, users can easily prvisin hw much cmpute resurces they need t prcess data intensive tasks such as web mining, data warehusing, lg file analysis, scientific calculatins and s n. It allws users fcus n the task at hand rather than wrry abut setting up cmputatinal framewrks t handle these tasks.
AWS: Strage Amazn s strage web service prvides a cst effective slutin fr string and retrieving data easily. Amazn s simple strage service (S3) and Elastic Bk Stre (EBS) are the main services in this area. Amazn Simple Strage Service (S3): Amazn S3 makes it easy fr develpers t stre and retrieve any amunt f data, at any time frm anywhere in the web. Using hashing technlgy where data is stred in key value pairs. The value being data bjects and key a unique identifier assigned t a develper, it prvides a fast, efficient and durable way fr string data.
AWS: Strage Amazn Elastic Bk Stre(EBS): Amazn EBS prvides blck strage instances that wrk independently f Amazn EC2 instances. They can act as backup data stres fr EC2 instances by prviding file-system like vlumes that can be munted n the machine.
AWS: Netwrking Amazn Virtual Private Clud (Amazn VPC): Amazn VPC allws users t prvisin an islated sectin f the AWS clud fr launching AWS resurces. With Amazn VPC, yu have cmplete cntrl ver the amunt f resurces within yur private space, including the range f IP addresses, web servers and ther cmpute resurces.
AWS Netwrking Amazn Rute53: Amazn Rute 53 is a highly available and scalable Dmain Name System (DNS) web service. It enables develpers t easily rute dmain names t AWS resurces.
AWS Database Amazn Dynam DB: Amazn s Dynam DB is a fully managed NOSQL database service that prvides fast and predictable perfrmance with seamless scalability.
AWS Database Amazn Relatinal Database Service (Amazn RDS): Amazn RDS is a web service that makes it easy t set up, perate, and scale a relatinal database in the clud. Amazn s RDS has similar t MySQL and Oracle database systems. Amazn RDS autmatically backs up data stred n instances and prvides an easy way t scale up t meet applicatin needs
Ggle App Engine Ggle App Engine enables yu t build web applicatins n the same scalable systems that pwer Ggle applicatins, which is great! App Engine applicatins are easy t build, easy t maintain, and easy t scale as yur traffic and data strage needs grw. With App Engine, there are n servers t maintain. Yu just uplad yur applicatin, and it's ready t serve t yur users.
Benefits f App Engine Easy t get started With App Engine yu write yur applicatin cde, test it n yur lcal machine and uplad it t Ggle with a simple click f a buttn r cmmand line script. Once yur applicatin is upladed t Ggle we hst and scale yur applicatin fr yu Free and risk-free develpment Yu can create an accunt and publish an applicatin that peple can use right away at n charge, and with n bligatin. When yu need t use mre resurces, yu can enable billing and allcate yur budget accrding t yur needs Autmatic Scalability N matter hw many users yu have r hw much data yur applicatin stres, App Engine can scale t meet yur needs. The reliability, perfrmance and security f Ggle infrastructure Trustable: The same security, privacy and data prtectin plicies we have fr Ggle's applicatins applies t all App Engine applicatins.
Applicatin Envirnment Dynamic web serving, with full supprt fr cmmn web technlgies Persistent strage with queries, srting and transactins Autmatic scaling and lad balancing APIs fr authenticating users and sending email using Ggle Accunts A fully featured lcal develpment envirnment that simulates Ggle App Engine n yur cmputer Task queues fr perfrming wrk utside f the scpe f a web request Scheduled tasks fr triggering events at specified times and regular intervals
Ggle App Engine: Language supprt Currently, Ggle App Engine supprts tw applicatin envirnments: Java and Pythn. Additinally, yur website templates can include JavaScript alng with yur HTML which, amng ther things, allws yu t write AJAX-enabled web applicatins. App Engine applicatins can als be written in Java r any JVMcmpatible language (e.g. JRuby, Grvy, Scala, etc.) and run in a Java 6 runtime envirnment. App Engine's Pythn runtime supprts Pythn 2.5 newer versins f Pythn, including Pythn 2.6, are nt currently supprted. Fr security reasns, sme Pythn mdules written in C wn't run in App Engine's sandbx.
SaaS and web 2.0 develpment Sftware as a service methdlgy has had a significant impact n the develpment f mdern web 2.0 applicatins. This is especially evident in mdern web develpment framewrks. Cnsider the fllwing cmmn use cases: Mst secure mdern web applicatins use captcha images as a way f preventing frm submissins by web bts and ther autmated entities. Facebk, twitter, Ggle+ site integratins are cmmn scial integratins. This culd be simple things such as like, tweets r +1 buttns r mre cmplex such as identity ntificatin and single sign n. Many web applicatins make use f URL shrtening services t enable easyt-read, transferable URLs. Many news sites, nline magazines and blgs pwer their cmmenting features by integrating web services frm service prviders such as Disqus, IntenseDebate and Facebk cmments API Ggle Maps, Calendar and Yutube are nw very cmmn as embeds in many websites. Given their dynamic structure, they are mre appealing cmpared t static map images r calendars.
Saas and web 2.0 develpment In the fllwing sectin, we examine the impact f SaaS methdlgy n the Zend Framewrk fr PHP. Other ppular web develpment framewrks such as Ruby n Rails share a similar influence
Zend Framewrk(ZF) The Zend Framewrk is a full stack, bject riented, web develpment framewrk. Began in late 2005 It cnsists f a library f cmpnents cvering mst f the used functinalities n the web such as frm creatin, authenticatin, access cntrl lists, input validatin, search and s n. It is primarily a Mdel View Cntrller (MVC) architecture. It als features a Use-at-will architecture: Users can use the framewrk ut f the bx r just use cmpnents f the framewrk as needed. Spnsred by Zend, the fficial PHP cmpany. Very active develper cmmunity. All cde develped g thrugh rigrus testing befre being deplyed in a release.
ZF and SaaS Zend Framewrk prmtes the cnsumptin and publishing f feeds via the Zend_Service and Zend_Rest APIs. We als lk at the Zend_Clud_Api which allws easy access t platfrm-type SaaS services such as Amazn Web Services.
Cnsuming feeds with Zend_Service The Zend_Service is an abstract class that serves as a fundatin fr REST & SOAP web service implementatins. Zend_Service has a hst f cncrete implementatins that act wrappers t ppular web service APIs. They include: Zend_Service_Twitter: Implements a client fr Twitter s REST based APIs. Zend_Service_Yah: A simple API fr accessing many f Yah s REST based web services Zend_Service_Ebay: A grup f APIs fr accessing Ebays web services Zend_Service_ReCaptcha Zend_Service_ShrtUrl: Prvides an API fr accessing a number f different URL shrtner services. Zend_Service_Flickr: A simple API fr using the Flickr REST Webservice and many mre..
Accessing platfrm clud services: Zend Framewrk Simple Clud API Starting in 2009, the Zend Framewrk included a simple clud API called Zend Clud. Zend Clud prvides a single unified API fr all the majr Sass clud prviders such as Amazn, Rackspace, Windws Azure and Nirvanix.
Zend Clud: Strage Service The Zend Clud Strage Service prvides a simple API fr file strage n the clud. The service abstracts the internal structure f files and they are nly identifiable by a string key. Right nw it supprts Amazn S3, Nirvanix and WindwsAzure.
Zend Clud s Strage service Example : Instantiating an Amazn S3 adapter $strage = Zend_Clud_StrageService_Factry::getAdapter(array( Zend_Clud_StrageService_Factry::STORAGE_ADAPTER_KEY =>'Zend_Clud_St, rageservice_adapter_s3', Zend_Clud_StrageService_Adapter_S3::AWS_ACCESS_KEY =>$amaznkey, Zend_Clud_StrageService_Adapter_S3::AWS_SECRET_KEY =>$amaznsecret, )); String an item with Zend Clud: $data = file_get_cntents('/my/lcal/dir/picture.jpg'); $returneddata = $strage->streitem('/my/remte/path/picture.jpg', $data); One just has t mdify the adapter t wrk with different prviders.
Publishing feeds Apart frm cnsuming web services, the Zend Framewrk makes it very easy t expse yur applicatin s services. It includes the Zend_REST_Server and Zend_Jsn_Server that enables the creatin f web services which return XML and JSON respnses.
Publishing web services: Zend_REST Zend_REST features tw cre implementatins: Zend_REST_Client and Zend_REST_Server. Zend_REST_Client prvides a simple prgrammatic API fr cnsuming RestFul web services while Zend_REST_Server prvides a simple interface that makes publishing yur applicatin data prvides a very simple interface fr making class methds and functinality publicly accessible. We shw a brief example f publishing a web service with Zend_REST_Server in the fllwing sectin
Zend_Rest_Server: cde example Wrking with Zend s Zend_Rest_Server cmpnent is very straightfrward. T illustrate this, we shw a simple cde sample belw: We begin by creating a class entity called Greetings with a single functin sayhell <?php Class Greetings { /** *@param string $user_ name *@return string */ } public functin sayhell($user_name){ return Hell $user_name. Hw is yur day ging? ; }
Zend_Rest_Server: example We nw create a cntrller class t handle incming requests. The cntrller class features an actin which instantiates the Zend_Rest_Server class class RestCntrller extends Zend_Cntrller_Actin { prtected $_server; public functin init() { $this->_server = new Zend_Rest_Server(); $this->_helper->viewrenderer->setnrender(); } public functin indexactin() { require_nce Greetings.php'; $this->_server->setclass( Greetings'); $this->_server->handle(); } } With the Zend_REST_SERVER in place, a RESTful call such as http://mysite/rest?methd=sayhell&name= Jack wuld return a result as fllws:
Zend_Rest_Server: cde example <Greetings generatr= zend versin= 1.0 > <result> <value>hell Jack. Hw are yu ding tday? </value> </result> </Greetings> Results can als be returned in JSON frmat if desired.
Hybrid f Traditinal & SaaS applicatins Althugh mst f ur discussins have highlighted the advantages f SaaS architectures, we ve als illustrated sme f the drawbacks f SaaS mst f which relate t security, privacy and reliability. T address these issues while taking advantages f SaaS, hybrids have develped recently SAP is ne f the cmpanies leading the way in this endeavr
Hybrid f Traditinal & SaaS : Many SaaS prviders tday take such an apprach. A gd example f which is Drpbx. Drpbx creates a virtualized directry cntaining user files n their machine thus enabling ffline access. Users are als able t access their data nline thrugh a web brwser.
Traditin & SaaS Hybrid Micrsft Office als uses a hybdrid traditinal SaaS sftware apprach. Office desktp suite can be installed lcally but dcuments can als be accessed and shared nline thrugh Micrsft Sky Drive.
Benefits f Traditinal & SaaS Hybrid Applicatins and data can be accessed ffline. This is especially useful in situatins where users have limited r n internet access such as n airplanes. Applicatins can be better secure as users may decide which applicatins t uplad t the clud r remain with lcally. Having lcal cpies f data serve as rain-cat frm cmplete data lss in situatins where the SaaS prvider is experiencing dwntime.
Summary SaaS greatly enhances the ability f develpers t scale their applicatin n demand and better suite custmer needs It encurages Agile practices by enabling prviders deliver frequent updates/patches withut waiting fr majr release cycles as in traditinal applicatins. SaaS applicatins hwever are susceptible t privacy, security and reliability cncerns Hybrid envirnments cmbining bth SaaS and traditinal applicatin methdlgies may be useful in scenaris f extremely sensitive data r where cnstant up-time must be maintained.
Summary Use f SaaS services is pervasive in the develpment and deplyment f mdern applicatins In cnclusin, the SaaS methdlgy is very mature and wuld play a central t the future f cmputing.
Reference [1] http://en.wikipedia.rg/wiki/clud_cmputing [2] http://aws.amazn.cm/ [3] http://ezinearticles.cm/saas---histry-and-a-lk- Ahead&id=2246590 [4] http://www.service-nw.cm/knwledge.d? sysparm_dcument_key=kb_knwledge, 4c8e15b90a0a3cc800e559d37a644090 [5] Clud business trends. http://www.cludbusinesstrends.cm/ 2011/05/19/analysis-saas-and-clud-cmputing-the-future-fsftware-develpment-stir-saas-clud-cmputing-s.html [6] Allen, Rb et al. Zend Framewrk in Actin. Manning Publicatins. December 2008. [7] The Zend Framewrk manual http://framewrk.zend.cm/ manual/1.11/en/manual.html [8] Ppe, Keith. Zend Framewrk 1.8 Web Applicatin Develpment. Packt Publishing. September 2009 [9] http://cde.ggle.cm/appengine/