White Paper Silver Liig of Cloud Computig - Key Priciples ad Best Practices CXOs eed to evaluate differet deploymet models, service models ad key characteristics of the cloud to implemet the precise spectrum of cloud systems depedig o orgaizatio s requiremets. The key characteristic of cloud computig is its ability to scale ad provisio computig power dyamically i a cost efficiet maer. Defiig priciples ad adherig to best practices are some of the key factors that would greatly cotribute to a optimal realizatio of the cloud computig potetial. Although this paper is ot iteded to offer a comprehesive list of priciples ad practices cocerig cloud computig, it is a attempt to cosolidate the key priciples ad best practices of the techology to help miimize issues ad challeges i cloud deploymet.
About the Author Dr. C. Parthiba Dr. C. Parthiba is a egagemet maager workig i TCS s Global Cosultig Practice Ifrastructure Solutios group. He has 14 years of experiece coverig a wide rage of areas icludig IT strategy, Ifrastructure Optimizatio, Architecture Solutios, Systems Itegratio ad leadig large cosultig egagemets. He holds a Doctorate i Applied Sciece from a premier uiversity i Cheai, Idia. 2
Table of Cotets Itroductio 4 Defiitio, Deploymet ad Service Models 4 Defiitio 4 Deploymet Models of Cloud Computig 4 Service Models of Cloud Computig 5 Six Key Priciples of Cloud Computig 7 Nie Best practices of Cloud Computig 9 Coclusio 13 Refereces 13 3
Itroductio The iformatio techology idustry has witessed a dramatic trasformatio over the last 10 years. Curretly, Cloud Computig remais arguably oe of the most talked about techology treds ad is expected to have a tremedous impact o IT delivery, hostig eviromets, ad fudametal computig resources. Further, cloud computig is a relatively eco-friedly techology as IT resources for multiple customers ca be cetrally maaged, thereby reducig overall eergy cosumptio levels. As leadig orgaizatios exhibit icreasig iterest i cloud computig, service providers should trai greater focus o providig robust cloud-computig platforms that offer outstadig service delivery.. Depedig o a orgaizatio s requiremets, CXOs should evaluate differet deploymet models, service models, ad key characteristics of the cloud to implemet the precise spectrum of cloud systems. The full potetial of cloud computig ca be achieved through a seamless cooperatio betwee govermets, idustry ad idividual users. Defiig priciples ad adherig to best practices are some of the key factors that would greatly cotribute to a optimal realizatio of the cloud computig potetial. The objective of this white paper is to propose key buildig blocks ad best practices iteded for both cosumers ad providers of cloud computig services. The paper also icludes a brief discussio of the defiitio, deploymet ad service models pertaiig to cloud computig. Defiitio, Deploymet ad Service Models Defiitio Cloud computig is a model for eablig ubiquitous, coveiet, o-demad etwork access to a shared pool of cofigurable computig resources (e.g., etworks, servers, storage, applicatios, ad services) that [1] ca be rapidly provisioed ad released with miimal maagemet effort or service provider iteractio. Deploymet Models of Cloud Computig Accordig to the Natioal Istitute of Stadards ad Techology, cloud computig ca be deployed usig [2] ay oe of the four models described below. : Private Cloud The cloud ifrastructure is provisioed exclusively for a sigle orgaizatio comprisig multiple cosumers. It may be maaged by the orgaizatio or a third party (or both) ad may exist both o the premises or offsite. Commuity Cloud The cloud ifrastructure is shared by several orgaizatios that have shared cocers (e.g., missio, security requiremets, policy, ad compliace cosideratios). It may be maaged by a commuity of these orgaizatios or a third party (or both) ad may exist either o or off premises. 4
Public Cloud The cloud ifrastructure is operated for the geeral public or a large idustry group ad is owed by a orgaizatio providig cloud services. It exists o the premises of the service provider. Hybrid Cloud The cloud ifrastructure is a compositio of two or more cloud ifrastructures (private, commuity, or public) that remai uique etities but are boud together by stadardized or proprietary techology that eables data ad applicatio portability (e.g., cloud burstig for load balacig betwee clouds). Service Models of Cloud Computig The orgaizatio s scope ad cotrol over the cloud computatioal eviromet ca be affected by the service models supported by the cloud. Described below are three of the most well-kow ad frequetly [3] used service models. Cloud Software as a Service (SaaS) The capability provided to the cosumer is to use the provider s applicatios ruig o a cloud ifrastructure. The applicatios are accessible from various cliet devices through a thi cliet iterface such as a web browser (e.g., web-based email). The cosumer does ot maage or cotrol the uderlyig cloud ifrastructure icludig etwork devices, servers, operatig systems, storage or the idividual applicatio capabilities with the possible exceptio of limited user-specific applicatio-cofiguratio settigs. I the case of SaaS, the usage is measured based o the umber of users, the time, per-executio, per- [1] record-processed, etwork badwidth cosumed, ad quatity/duratio of data stored. Cloud Platform as a Service (PaaS) The capability provided to the cosumer is to deploy oto the cloud ifrastructure cosumer-created or acquired applicatios created usig programmig laguages ad tools supported by the provider. The cosumer does ot maage or cotrol the uderlyig cloud ifrastructure icludig etwork, servers, operatig systems, or storage, but has cotrol over the deployed applicatios ad, possibly, the cofiguratio of the applicatio-hostig eviromet. I case of PaaS, the usage is measured based o the umber of subscribers, the kid of subscribers (e.g., developers vs. applicatio ed users), storage, processig, or etwork resources cosumed by the platform, [1] requests serviced ad the time the platform is i use. Cloud Ifrastructure as a Service (IaaS) The capability provided to the cosumer is to provisio processig, storage, etworks ad other fudametal computig resources to deploy ad ru arbitrary software, which ca iclude operatig systems ad applicatios. The cosumer does ot maage or cotrol the uderlyig cloud ifrastructure but has cotrol over operatig systems, storage, deployed applicatios ad, possibly, limited cotrol over the selectio of etworkig compoets (e.g., host firewalls). 5
I case of IaaS, the usage fee is measured based o the per CPU hour, data GB stored per hour, etwork badwidth cosumed or ifrastructure used (e.g., IP addresses) per hour, ad value-added services used [1] (e.g., moitorig, automatic scalig). Scope ad Cotrol The differeces i scope ad cotrol betwee the cloud cosumer ad cloud provider are illustrated i the diagram below: Cloud Cosumer SaaS Applicatio Layer PaaS laas Middleware Layer PaaS laas SaaS Operatig System Layer Cloud Provider The arrows at the left ad right of the diagram deote the approximate rage of the cloud provider s ad cosumer s scope ad cotrol over the cloud eviromet for each service model. I geeral, the level of support available from a cloud provider ad the scope ad cotrol of the cloud cosumer are iversely proportioal. i.e., the higher the level of support available from a cloud provider, the more arrow the cotrol the cosumer has over the system. Services Available The table give below provides the sample services available for cloud cosumers i each of the service models. Iaas PaaS SaaS Storage Database ERP Cotet Delivery Networks Busiess Itelligece Huma Resources Backup ad Recovery Developmet ad Testig Billig Services Maagemet Itegratio Sales Platform Hostig Applicatio Deploymet CRM Compute Ad Other Services Cotet Maagemet Ad Other Services Ad Other Services 6
Six Key Priciples of Cloud Computig The cloud computig techology cotiues its rapid trasitio from a excitig urealized cocept to a practical, cost-effective, iovative, ad efficiet solutio. Oe of the key features of cloud computig is its ability to scale ad provide pay-as-you-go computig resources based o the dyamic requiremets of a orgaizatio. Eve as cloud computig evolves at a swift pace, the iformatio techology idustry still requires a comprehesive, clear-cut aalysis o how this computig paradigm ca ifluece ad impact orgaizatios ad how it ca be icorporated with existig techologies. Although the cloud presets tremedous opportuities ad value for orgaizatios, usual IT requiremets (security, itegratio, ad so forth) still apply. I additio, ew issues may arise because of the multi-teat ature (iformatio from multiple compaies may reside o the same physical hardware) of cloud computig, the merger of applicatios ad data, ad the fact that a compay s workloads might reside outside of their physical o-premise data ceter. Although cloud computig offers great opportuities, it should be oted that its effective implemetatio poses several risks ad barriers. Further, cloud providers should realize that the full potetial of cloud computig ca be realized oly by esurig that it remais ope, iteroperable ad portable. Described below are a set of core priciples ad best practices iteded for CXOs, govermets, IT users ad orgaizatios that are lookig to employ cloud computig. Every cloud cosumer presets a uique set of requiremets, which creates sigificat challeges whe defiig priciples for every aspect ad creatig a sigle stadard cloud. Moreover, there are six key priciples that must be [4] adhered to esure the cloud is ope ad meets the choice, flexibility, elasticity ad agility of the orgaizatio : Priciple 1 Statemet Implicatios Leverage stadards for Cloud Adoptio. Cloud providers must work together to esure that the challeges to cloud adoptio (security, itegratio, portability, iteroperability, goverace/maagemet, meterig/moitorig) are addressed through ope collaboratio ad the appropriate use of stadards. Large orgaizatios will be able to itegrate cloud computig ito existig IT systems ad applicatios with miimal impact o issues such as security, iteroperability, data maagemet ad measuremet criteria. Priciple 2 Statemet Implicatios Elimiate vedor-lock-i risks. Cloud providers must esure that they do ot misuse their market positio to lock-i customers to their platforms ad limit their choice of providers. Whe a orgaizatio chooses a provider or architecture or usage model, a ope cloud will make it easier for them to switch to a differet provider or architecture. If the orgaizatio eeds to chage providers they ca do so easily. 7
Priciple 3 Statemet Implicatios Avoid reivetig stadards. Cloud providers must use ad adopt existig stadards wherever appropriate. The IT idustry has ivested heavily i existig stadards orgaizatios; there is o eed to duplicate or reivet them. It will reduce challeges pertaiig to the adoptio of cloud techology ad the lead times associated with movig from i-premise data ceters to the cloudcomputig eviromet. Priciple 4 Statemet Implicatios Defie stadards o demad. Whe ew stadards (or adjustmets to existig stadards) are eeded, we must be judicious ad pragmatic to avoid creatig too may. We must esure that stadards promote iovatio ad do ot ihibit it. Stadards ad polices eed to be defied oly for matured techologies ad processes to avoid rework. Priciple 5 Statemet Implicatios Address customer-cetric eeds. Ay commuity effort aroud the ope cloud should be drive by customer eeds, ad ot merely the techical eeds of cloud providers, ad should be tested or verified agaist real customer requiremets. Orgaizatios should esure that the ew stadards ad polices are defied oly o the basis of cloud customer requiremets to avoid uecessary effort ad costs. Priciple 6 Statemet Implicatios Esure optimal goverace ad maagemet. Cloud computig stadards orgaizatios, advocacy groups, ad commuities should work together ad stay coordiated, esurig that efforts do ot overlap. Orgaizatios should employ appropriate maagemet practices ad cotrols whe udertakig cloud computig. Strog maagemet practices are essetial for operatig ad maitaiig a robust cloud computig solutio. Moitorig the orgaizatio s iformatio system assets ad assessig the implemetatio of policies, stadards, procedures, ad guidelies will esure the cotiued deploymet of appropriate stadards. 8
Nie Best Practices of Cloud Computig As cloud computig gais i popularity, orgaizatios are likely to use differet types of cloud services. Applicatios might use a cloud storage service, a cloud message queue ad eve maage virtual machies ruig i the cloud. Cloud computig techologies ca be implemeted i a wide variety of architectures, uder differet service ad deploymet models, ad ca coexist with other techologies ad software desig approaches. The challeges ad issues i implemetig cloud computig are formidable, especially for public clouds whose ifrastructure ad computatioal resources are owed by a outside party that provides those services to the geeral public cosumers. Istitutig best practices for such services would be valuable ad offer a basis for utilizig the potetial of cloud computig to the maximum extet. As per the idustry practice of deploymet ad service models, [5] the most commo cloud scearios are as follows : Ed User to Cloud l Applicatios ruig o the cloud ad accessed by ed users. Eterprise to Cloud to Ed User l Applicatios ruig i the public cloud ad accessed by employees ad customers. Eterprise to Cloud l Cloud applicatios itegrated with iteral IT capabilities. Eterprise to Cloud to Eterprise l Cloud applicatios ruig i the public cloud ad iteroperatig with parter applicatios (supply chai). Private Cloud l A cloud hosted by a orgaizatio iside that orgaizatio s firewall. Hybrid Cloud l Multiple clouds work together, coordiated by a cloud broker that federates data, applicatios, user idetity, security ad other details. Chagig Cloud Vedors l A orgaizatio usig cloud services decides to switch providers or work with additioal providers The above scearios are defied based o their requiremets ad features. Described below are some of the best practices that ca be employed i cloud computig scearios. 9
Best Practice 1 Descriptio Meterig ad Moitorig I a measured service, aspects of the cloud service are cotrolled ad moitored by the cloud provider. This is crucial for billig, access cotrol, resource optimizatio, capacity plaig ad other tasks. All cloud services must be metered ad moitored for cost cotrol, charge backs ad provisioig except for ed user to cloud sceario. Best Practice 2 Descriptio Maagemet ad Goverace It is a straightforward process to ope a accout ad begi usig cloud services o the public cloud. This might create the risk of idividuals i a eterprise usig cloud services for ulawful purposes. Maagig VMs ad cloud services such as storage, databases ad message queues effectively is eeded to track the services beig used. Goverace is a crucial criterio to esure that policies ad govermet regulatios are followed wherever cloud computig is used. Idustry ad geography-specific requiremets are other types of goverace. Cloud cosumers must rely o the cloud provider to eforce policy ad goverace through techical meas that are "baked ito" the ifrastructure as IaaS. Maagemet of VM ad goverace of polices ad other regulatios should be eforced i all the cloud computig scearios except for the ed-user to cloud sceario. Best Practice 3 Descriptio Security Cloud computig scearios ivolvig a eterprise will usually have more sophisticated security requiremets tha those ivolvig a sigle ed user. Similarly, relatively more advaced eterprise-based cloud scearios will have equally advaced security requiremets. It is madatory to have world class security i all the cloud computig scearios. To achieve the ecessary security, cloud service providers must adopt comprehesive security practices ad procedures icludig: Well-recogized, trasparet ad verifiable security criteria. Robust idetity, autheticatio ad access cotrol mechaisms commesurate with the level of sesitivity of the data. Comprehesive ad ogoig testig of security measures before ad after deploymet. 10
Best Practice 4 Descriptio Virtual Machie (VM) Image Format A VM created for oe cloud vedor s platform should be portable to aother vedor s platform. Ay solutio to this requiremet must accout for differeces i the ways cloud vedors attach storage to virtual machies Applicatio Programmig Iterfaces (APIs) for images must support uploadig, deployig startig, stoppig, restartig, ad deletig images. Ifrastructure maagemet APIs that cotrol details such as firewalls, ode maagemet, etwork maagemet ad load balacig should be portable across all cloud computig scearios except ed user to cloud sceario. Best Practice 5 Descriptio Cloud Database API The eterprise cloud scearios require commo APIs for access to cloud storage services. Writig custom code that works oly for a particular vedor s cloud service locks the eterprise ito that vedor s system ad elimiates the fiacial beefits ad flexibility that cloud computig provides. Commo cloud storage APIs should be i place for all cloud computig scearios except ed user to cloud ad private cloud scearios. Best Practice 6 Descriptio Cloud Database API APIs for coectig, creatig ad elimiatig databases ad tables should be cosistet. Cloud database vedors have eforced certai restrictios to make their products more elastic ad limit the possibility of queries agaist large data sets that cosume sigificat processig resources. For example, some cloud databases do ot allow jois across tables, ad some do ot support a true database schema. Those restrictios are a major challege to movig betwee cloud database vedors, especially for applicatios built o a true relatioal model. It is, therefore, a best practice to have commo cloud database APIs i place for all cloud computig scearios except ed user to cloud ad private cloud scearios. 11
Best Practice 7 Descriptio Data ad Applicatio Federatio Federatio is the act of combiig data or idetities across multiple systems. Federatio ca be doe by a cloud provider or by a cloud broker. Eterprise applicatios should combie data from multiple cloud-based sources, ad they should coordiate the activities of applicatios ruig i differet clouds. Private cloud ad ed user to cloud scearios eed ot combie data from multiple systems. Best Practice 8 Descriptio Service Level Agreemet (SLA) A SLA is a cotract betwee a provider ad a cosumer that specifies cosumer requiremets ad the provider s commitmet to them. Typically, a SLA icludes items such as uptime, privacy, security ad backup procedures. I additio to the basic SLAs required by ed users, aother best practice for eterprises that eter ito cotracts is to establish a stadard process for bechmarkig performace. There must be a uequivocal way of defiig what a cloud provider will deliver, ad there also must be a uambiguous way of measurig ad moitorig what was actually delivered. A machie readable laguage for SLAs is oe of the stadard formats for expressig a SLA. I case of hybrid computig, this allows the cloud provider to select resources accordig to the cosumer s terms without huma itervetio. Best Practice 9 Descriptio Life Cycle Maagemet Eterprises must be able to maage the lifecycle of applicatios ad documets. This requiremet icludes versioig applicatios ad the retetio ad destructio of data. Discovery is a major issue for may orgaizatios. There are substatial legal liabilities if certai data is o loger available. I additio to data retetio, a eterprise may be iterested i destroyig data at some poit. May orgaizatios have legal requiremets that data must be kept for a certai period of time. Some orgaizatios also require that data be deleted after a certai period of time. Cloud providers must be able to prove they are compliat with these policies. It should be oted that private cloud ad ed user to cloud scearios do ot require life cycle maagemet processes. 12
Coclusio Cloud computig techology has the potetial to greatly ifluece the systems ad etworks of orgaizatios. The key characteristic of cloud computig is its ability to scale ad provisio computig power dyamically i a cost efficiet maer. The cotiuous growth i cloud computig would udeiably culmiate i IT iovatio ad such iovatio should be guided by priciples ad best practices towards opeess, iteroperability ad portability. Although this paper was ot iteded to offer a comprehesive list of priciples ad practices cocerig cloud computig, it was a attempt to cosolidate the key priciples ad best practices of the techology to help miimise issues ad challeges i cloud deploymet. Refereces [1] DRAFT Cloud Computig Syopsis ad Recommedatios, Recommedatios of the Natioal Istitute of Stadards ad Techology, Special Publicatio 800-146, May 2011 [2] NIST Cloud Computig Stadards Roadmap Versio 1.0, NIST, Special Publicatio 500-291, July 2011 [3] Guidelies o Security ad Privacy i Public Cloud Computig, NIST, Ja 2011 [4] Ope Cloud Maifesto, http://www.opecloudmaifesto.org/ [5] Cloud Computig Use Cases, Cloud Computig Use Case Discussio Group Versio 4.0, July 2010 13
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