The subtle art of e-triageLast TimeE-triageSlide 4ExampleBusiness Roles?Reduce to a Technical ProblemSlide 8Slide 9Basic MaximsPieces of the systemTerminologyComplexity!The SystemChoicesRoll Your Own?Why is Weblogic a Success?All About WeblogicWeblogic LimitsBusiness TradeoffsProject CreepAvoiding Project CreepScalabilityScalability is Hard!Fundamental Issues of ScaleDoes the Internet “Scale”?How do technologies scale?Web scaling issuesAkamai ApproachA Good Idea?Pre- and Post-AkamaiSlide 32A good idea?More Akamai IssuesAlternatives?Other kinds of worriesNotice how Technical Issues Blur…Stepping BackManagement Does and Don’tToughest Issues: Scale and SecurityToo Many ObjectivesBusiness MethodologyStyles of eBusinessSlide 44Slide 45Slide 46Enough for nowThe subtle art of e-triageProfessor Ken BirmanDept. of Computer ScienceCornell UniversityLast TimeWe learned that complex e-commerce systems are at e-riskWe saw that e-risks take many forms:System complexityFailure to plan for failuresPoor project managementCan we do better?E-triageIn a hospital emergency room, nurse sees a bunch of sick peopleE-triageIn a hospital emergency room, nurse sees a bunch of sick peopleCan’t deal with everything at once, so she decides what problems are most urgentWe can use the same idea to “triage” risks to an e-commerce projectExampleYour e-company will host the ultimate web site for women’s cosmetic productsScan in pictures of your clientsSoftware on the web site makes cosmetic recommendationsDepicts results right on the imagePlan is to be the world’s largest direct sales channel for cosmeticsBusiness Roles?You write the checks, but also set the toneYou need to learn enough about the choices to guide your technology people to make the right onesYour role is “triage”but of managerial typeReduce to a Technical ProblemOption A: Hire a bunch of hackersExplain the vision, trust themThey start to mumble about Oracle, Sybase, Informix, VRML, HHTPS, XML, IE 5.0 versus Netscape 3.2, scalable cluster servers…You zone outProblem: your fate in their handsReduce to a Technical ProblemOption B:You bring in the expertsIBM shows up Monday, HP on Tuesday…Their marketing guys want moneyTheir technical guys are incomprehensibleYou zone outProblem: your money in their hands. Didn’t IBM blow that air-traffic project?Reduce to a Technical ProblemOption C:You decide to manage the project in an effective wayBefore bringing in technical people, can you sort out the big issues?Problem: you aren’t a technical person. (But they know that, and yet they look to you for guidance because you “run the show”)Basic MaximsWe can’t do everythingWe need to focus on what really mattersEach technical feature adds complexityCan we achieve a spare, elegant solution that has precisely the mechanisms we need to excel?On each choice, ask “why does this matter”? “What will be the downstream costs?”Pieces of the systemThe Internet: customers use it to talk to your companyYour web server: hosts the “content”A database of customer informationHer face, her age, past purchases, etcA database of cosmetic productsA database of advertising materialsBack-office system “clears” transactionsTerminologyA database is a big collection of information organized for easy accessInternet technologies provide a way for client systems (browsers) to issue some form of database request to your systemUsually the request occurs by fetching a “computed” web pageInternally, your company may have information spread over multiple sites and hidden behind a firewall at each locationComplexity!All of this takes an initially simple idea and makes it complexThe data may not be at one placePerhaps many systems will need to cooperate to satisfy your customersWith lots of customers we need to worry about how the model “scales”The SystemInternetNewMe.comChoicesHow to build the web site itselfWe’ll focus on BEA WeblogicThis technology is a hot product that many feel “does it all”There are lots of other similar projects, but Weblogic is typical and most successfulBut picking the technology doesn’t really solve the business problem…Roll Your Own?With Weblogic you Use their “tools”But your own people build the actual web siteTheir tools provide:Basic functionality for web sites on which people can do shopping-cart style purchasesDatabase to track inventory and customer historiesThey even handle credit card transactionsWhy is Weblogic a Success?Very easy to get slick web sites off the groundBuilt in solutions for most of the things you might need to doAnd BEA has related products to link the web site you build to your other “systems” within your companyAll of this makes for a good story – “the whole story” for building web sitesAll About WeblogicThe basic architecture:On the client side, “cookie” tracks the contents of the shopping cartRequests are received by the Weblogic load-balancing proxyBehind it, a cluster of servers run the web pagesserverproxyWeblogic LimitsFor extremely popular web sites, the approach Weblogic takes won’t scaleRemote users will get slow responseHard to customize content so that each user sees a “private” set of web pagesAnd the database itself is built by other companies, forcing you to make a choiceHigh availability a big issue at this levelYet their product literature claims that Weblogic scales extremely well.Business TradeoffsThese limitations are serious worriesNear term, they won’t impact youBuilding a great site will come down to hiring great graphics peopleBut long term, they point to problems scaling your business modelYou might not easily have discovered the problemIn effect, the technology choice may dictate the business model and price point… at a stage when you didn’t even know you were buying into them!Project CreepA common phenomenonYou make sensible initial decisionsAnd the technology seems to workYour company gets off the groundBut then hit limitsThese force you to hack solutionsYour business suffers downtime… unreliabilityUltimately, your people do more and more hacking and may have to rebuild from scratch… or worse!Avoiding Project CreepThe key to
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