Case Study: Amazon AWS CSE40822–CloudComputing

Prof.DouglasThainUniversityofNotreDame

Caution to the Reader: Herein are examples of prices consulted in fall 2018, to give a sense of the magnitude of costs. Do your own research before spending your own money!

Several Historical Trends •  SharedUtilityComputing

•  1960s–MULTICS–ConceptofaSharedComputingUtility•  1970s–IBMMainframes–rentbytheCPU-hour.(Fast/slowswitch.)

•  DataCenterCo-location•  1990s-2000s–Rentmachinesformonths/years,keepthemclosetothenetworkaccesspointandpayaflatrate.Avoidrunningyourownbuildingwithutilities!

•  PayasYouGo•  Early2000s-Submitjobstoaremoteserviceproviderwheretheyrunontherawhardware.SunCloud($1/CPU-hour,Solaris+SGE)IBMDeepCapacityComputingonDemand(50cents/hour)

•  Virtualization•  1960s–OS-VM,VM-360–Usedtosplitmainframesintologicalpartitions.•  1998–VMWare–FirstpracticalimplementationonX86,butatsignificantperformancehit.

•  2003–Xenparavirtualizationprovidesmuchperf,butkernelmustassist.•  Late2000s–IntelandAMDaddhardwaresupportforvirtualization.

Virtual-* Allows for the Scale of Abstraction to Increase Over Time • Runoneprocesswithincertainresourcelimits.

OpSyshasvirtualmemory,virtualCPU,andvirtualstorage(filesystem).• Runmultipleprocesseswithincertainresourcelimits.

Resourcecontainers(Solaris),virtualservers(Linux),virtualimages(Docker)• Runanentireoperatingsystemwithincertainlimits.

Virtualmachinetechnology:VMWare,Xen,KVM,etc.• Runasetofvirtualmachinesconnectedviaaprivatenetwork.

Virtualnetworks(SDNs)provisionbandwidthbetweenvirtualmachines.• Runaprivatevirtualarchitectureforeverycustomer.

Automatedtoolsreplicatevirtualinfrastructureasneeded.

Amazon AWS

•  GrewoutofAmazon’sneedtorapidlyprovisionandconfiguremachinesofstandardconfigurationsforitsownbusiness.

•  Early2000s–Bothprivateandshareddatacentersbeganusingvirtualizationtoperform“serverconsolidation”

•  2003–InternalmemobyChrisPinkhamdescribingan“infrastructureservicefortheworld.”

•  2006–S3firstdeployedinthespring,EC2inthefall•  2008–ElasticBlockStoreavailable.•  2009–RelationalDatabaseService•  2012–DynamoDB•  2014–Lambda("Serverless")•  2016(?)–ElasticContainerService•  Doesitturnaprofit?

Terminology

•  Instance=Onerunningvirtualmachine.•  InstanceType=hardwareconfiguration:cores,memory,disk.•  InstanceStoreVolume=Temporarydiskassociatedwithinstance.•  Image(AMI)=Storedbitswhichcanbeturnedintoinstances.• KeyPair=CredentialsusedtoaccessVMfromcommandline.• Region=Geographiclocation,price,laws,networklocality.• AvailabilityZone=Subdivisionofregionthatisfault-independent.

EC2 Pricing Model • FreeUsageTier• On-DemandInstances

•  Startandstopinstanceswheneveryoulike,costsareroundeduptothenearesthour.(Worstprice)

• ReservedInstances• Payupfrontforone/threeyearsinadvance.(Bestprice)• Unusedinstancescanbesoldonasecondarymarket.

• SpotInstances•  Specifythepriceyouarewillingtopay,andinstancesgetstartedandstoppedwithoutanywarningasthemarkedchanges.(KindoflikeCondor!)

http://aws.amazon.com/ec2/pricing/

Free Usage Tier

•  750hoursofEC2runningLinux,RHEL,orSLESt2.microinstanceusage

•  750hoursofEC2runningMicrosoftWindowsServert2.microinstanceusage

•  750hoursofElasticLoadBalancingplus15GBdataprocessing•  30GBofAmazonElasticBlockStorageinanycombinationofGeneralPurpose(SSD)orMagnetic,plus2millionI/Os(withMagnetic)and1GBofsnapshotstorage

•  15GBofbandwidthoutaggregatedacrossallAWSservices•  1GBofRegionalDataTransfer

On-De

man

dInstan

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Reserved

Instan

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SpotIn

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Surprisingly, you can’t scale up that large.

Simple Storage Service (S3)

•  Abucketisacontainerforobjectsanddescribeslocation,logging,accounting,andaccesscontrol.Abucketcanholdanynumberofobjects,whicharefilesofupto5TB.Abuckethasanamethatmustbegloballyunique.

•  FundamentaloperationscorrespondingtoHTTPactions:•  http://bucket.s3.amazonaws.com/object•  POSTanewobjectorupdateanexistingobject.•  GETanexistingobjectfromabucket.•  DELETEanobjectfromthebucket•  LISTkeyspresentinabucket,withafilter.

•  Abuckethasaflatdirectorystructure(despitetheappearancegivenbytheinteractivewebinterface.)

Easily Integrated into Web Applications <form action="http://examplebucket.s3.amazonaws.com/" method="post" enctype="multipart/form-data"> <input type="input" name="key" value="user/user1/" /> <input type="hidden" name="acl" value="public-read" /> <input type="hidden" name="success_action_redirect" value="http://examplebucket.s3.amazonaws.com/successful_upload.html" /> . . . <input type="text" name="X-Amz-Credential” value="AKIAIOSFODNN7EXAMPLE/20130806/us-east-1/s3/aws4_request" /> . . . <input type="submit" name="submit" value="Upload to Amazon S3" /> </form>

http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-post-example.html

Bucket Properties

• Versioning–Ifenabled,POST/DELETEresultinthecreationofnewversionswithoutdestroyingtheold.

•  Lifecycle–Deleteorarchiveobjectsinabucketacertaintimeaftercreationorlastaccessornumberofversions.

• AccessPolicy–Controlwhenandwhereobjectscanbeaccessed.• AccessControl–Controlwhomayaccessobjectsinthisbucket.•  Logging–Keeptrackofhowobjectsareaccessed.• Notification–Benotifiedwhenfailuresoccur.

S3 Weak Consistency Model DirectquotefromtheAmazondeveloperAPI:“Updatestoasinglekeyareatomic….”“AmazonS3achieveshighavailabilitybyreplicatingdataacrossmultipleserverswithinAmazon'sdatacenters.IfaPUTrequestissuccessful,yourdataissafelystored.However,informationaboutthechangesmustreplicateacrossAmazonS3,whichcantakesometime,andsoyoumightobservethefollowingbehaviors:

•  AprocesswritesanewobjecttoAmazonS3andimmediatelyattemptstoreadit.Untilthechangeisfullypropagated,AmazonS3mightreport"keydoesnotexist."

•  AprocesswritesanewobjecttoAmazonS3andimmediatelylistskeyswithinitsbucket.Untilthechangeisfullypropagated,theobjectmightnotappearinthelist.

•  Aprocessreplacesanexistingobjectandimmediatelyattemptstoreadit.Untilthechangeisfullypropagated,AmazonS3mightreturnthepriordata.

•  Aprocessdeletesanexistingobjectandimmediatelyattemptstoreadit.Untilthedeletionisfullypropagated,AmazonS3mightreturnthedeleteddata.”

Elastic Block Store

• AnEBSvolumeisavirtualdiskofafixedsizewithablockread/writeinterface.ItcanbemountedasafilesystemonarunningEC2instancewhereitcanbeupdatedincrementally.Unlikeaninstancestore,anEBSvolumeispersistent.

•  (ComparetoanS3object,whichisessentiallyafilethatmustbeaccessedinitsentirety.)

•  Fundamentaloperations:•  CREATEanewvolume(1GB-1TB)•  COPYavolumefromanexistingEBSvolumeorS3object.•  MOUNTononeinstanceatatime.•  SNAPSHOTcurrentstatetoanS3object.

EBS is approx. 3x more expensive by volume and 10x more expensive by IOPS than S3.

Use Glacier for Cold Data • GlacierisstructuredlikeS3:avaultisacontainerforanarbitrarynumberofarchives.Policies,accounting,andaccesscontrolareassociatedwithvaults,whileanarchiveisasingleobject.

• However:•  AlloperationsareasynchronousandnotifiedviaSNS.•  Vaultlistingsareupdatedonceperday.•  Archivedownloadsmaytakeuptofourhours.•  Only5%oftotaldatacanbeaccessedinagivenmonth.

• Pricing:•  Storage:$0.01perGB-month•  Operations:$0.05per1000requests•  DataTransfer:LikeS3,freewithinAWS.

•  S3PoliciescanbesetuptoautomaticallymovedataintoGlacier.

Durability •  AmazonclaimsaboutS3:

•  AmazonS3isdesignedtosustaintheconcurrentlossofdataintwofacilities,e.g.3+copiesacrossmultipleavailabledomains.

•  99.999999999%durabilityofobjectsoveragivenyear.•  AmazonclaimsaboutEBS:

•  AmazonEBSvolumedataisreplicatedacrossmultipleserversinanAvailabilityZonetopreventthelossofdatafromthefailureofanysinglecomponent.

•  Volumes<20GBmodifieddatasincelastsnapshothaveanannualfailurerateof0.1%-0.5%,resultingincompletelossofthevolume.

•  CommodityharddiskshaveanAFRofabout4%.•  AmazonclaimsaboutGlacieristhesameasS3:

•  AmazonS3isdesignedtosustaintheconcurrentlossofdataintwofacilities,e.g.3+copiesacrossmultipleavailabledomainsPLUSperiodicinternalintegritychecks.

•  99.999999999%durabilityofobjectsoveragivenyear.

•  Bewareofoversimplifiedargumentsaboutlow-probabilityevents!

Amazon Elastic File Services (EFS)

•  EFSisastandalonefileservicedesignedtosharedamongVMs.•  FileSystemInstance–Files,directories,storageallocation,multipleAZs•  MountTarget–DNSname,IPaddress,NFStarget,singleAZ:file-system.id.efs.aws-region.amazonaws.com

•  InsideofVM,usenormalNFSconnectiontothemounttarget:

mount –t nfs –o rsize=1M,wsize=1M,… file-system-dns-name /mnt/data

https://docs.aws.amazon.com/efs

Amazon ElasticFile Services (EFS)

• DataConsistencyModel• "closetoopen"consistencysemantics.• In(normal)asynchronous,sequentialI/Omode:

• Dataisdurableafteranfsyncoraclose.• Dataisvisibletootherprocessesthatopenafteryouclose.•  Indeterminatecase:ProcessBopensbeforeProcessAcloses.

• In(explicit)synchronousI/Omode(O_DIRECT)• Non-appendingwritesareimmediatelyvisible.•  (Thisimpliesthatappendingwritesarenot.Why?)• Hint:Sizeoffileisapropertyofmetadata.

Everything in AWS is Carefully Limited!

•  50KB/sperGBofdatainfreethroughput•  250MB/sMaxEFSthroughputperEC2Instance•  128userIDscanhaveopenfiles•  32Kopenfilesonasingleinstance•  4080Bmaxsymboliclinklength•  1000maximumdirectorydepth•  47.9TiBmaxbytesperfile•  87maxlocksperfile(?)•  7000fileoperationspersecond

https://docs.aws.amazon.com/efs/latest/ug/limits.html

Amazon EFS Pricing

EBS EFSLatency "lowest"

(localhardware)"low"(network)

MaxThroughput 2GB/s 10GB/s

Clients(VMs) Single O(1000)

StorageCostPerMonth

$0.05/GB(MagneticDisk)

$0.30/GB

AccessCostPerMonth

$0.05/1MIOPS(MagneticDisk

$6.00/MB/sXput

Serverless Computing • Aside:Worst.Name.Ever.(Exceptfordevicelesscomputing.)•  "Serverlesstakesitastepfurther,whereyoudon'teventhinkabouttheinfrastructure.Youthinkoffunctionsthatyourcodeneedstoperform."–Prof.PaulBrenner,NotreDameCRC*

• KeyIdea:•  Defineafixedfunction(andassociatedstate)once.•  Invokethatfunctiononsmallamountsofdatamanytimes.•  Teardownthefunction(andstate).

• Cloudprovidertakestheresponsibilityofscalingthesystemupanddowninordertomeettheofferedload.

*https://cacm.acm.org/magazines/2018/2/224625-going-serverless/fulltext

Amazon Lambda

• WithAWSLambda,youcanruncodewithoutprovisioningormanagingservers.Youpayonlyforthecomputetimethatyouconsume—there’snochargewhenyourcodeisn’trunning.Youcanruncodeforvirtuallyanytypeofapplicationorbackendservice—allwithzeroadministration.JustuploadyourcodeandLambdatakescareofeverythingrequiredtorunandscaleyourcodewithhighavailability.YoucansetupyourcodetoautomaticallytriggerfromotherAWSservicesorcallitdirectlyfromanywebormobileapp.

https://docs.aws.amazon.com/lambda/index.html#lang/en_us

Amazon Lambda

•  SupportedEnvironments:•  Node.js,Python,C#,Go,Java,PowerShell

•  Encouragedmodeofuse:•  Defineaself-containedworkfunctioninthenativelanguage.• Writeahandlerfunctionthatpacks/unpacksJSONandinvokestheworkfunc.

• Possible,butlessencouragedandcancausetrouble:•  Handlerfunctionusessystem/exec/shelltoinvokeexternalprocessesinordertocomputeresult.

•  Thelambdaruntimeisdefinedrelativetoalanguageruntime(e.g.Python2.7,Python3.0)andnotspecificabouttheOSenvironment.

Requirements

•  Functionmustbestateless.• Noaffinitywiththeunderlyingcomputeinfrastructure.•  Localfilesystemaccess,childprocesses,andsimilarartifactstobelimitedtothelifetimeoftherequest.

• PersistentstateshouldbestoredinAmazonS3,DynamoDB,etc..

• P.S.Easytosay,butrequiresdisciplinetosticktothis.• P.P.S.Doesthissoundsimilartoanothersystemwehavediscussed?

Defining a Function

• Uniquename.• Providethecode(obviously)• Useadeploymentpackageifaddldependenciesneeded.•  Statememoryrequiredbyfunction.(CPUisproportional)•  Statethetimeoutforthefunction.(Defaultis3seconds!)• GivepermissionstoaccessotherAWSservices.

How does it work?

•  (Sketchontheboard)

Lambda Pricing in Oct 2018

• Atfirst:•  First1Minvocationsarefree.•  400,000GB-sofmemoryxexecutiontimearefree.

•  Then:•  $0.20per1Minvocations.•  $0.00001667perGB-sofmemoryxexecutiontime.

• Careful:Functionscanincuraddlcostsbyinvokingotherservices.

Perf

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Lim

its

Principle: Hierarchy of Invocation Costs

•  Stepstogettingremoteworkdone:•  Provisionphysicalhardware.•  Activatevirtualmachineonhardware.•  Deploycontaineronvirtualmachine.•  Startprocessand"warmup"theprogram.•  Loadnecessarydatafortask.•  Invokethefunctionthatconstitutesyourwork.

•  Shouldwesetup/teardowneverythingforeveryinvocation?• Whatarethepros/consofstayingatthelastlevel?•  (Hint:Thinkaboutwhatotherconcurrentusersmaydo.)

Architecture Center •  IdeasforconstructinglargescaleinfrastructuresusingAWS:http://aws.amazon.com/architecture/

Command Line Setup • Gotoyourprofilemenu(yourname)intheupperrighthandcorner,select“SecurityCredentials”and“ContinuetoSecurityCredentials”

•  Select“AccessKeys”•  Select“NewAccessKey”andsavethegeneratedkeyssomewhere.•  Edit~/.aws/configandsetituplikethis:

• Nowtestit:awsec2-describe-instances

Notethesyntaxhereisdifferentfromhowitwasgiveninthewebconsole!AWSAccessKey=XXXXXXAWSSecretAccessKey=YYYYYYYYY

[default]output=jsonregion=us-west-2aws_access_key=XXXXXXaws_secret_access_key=YYYYYYYYYYYY

S3 Command Line Examples

awss3 mb s3://bucket... cp localfiles3://bucket/key mv s3://bucket/keys3://bucket/newname

ls s3://bucket rm s3://bucket/key rb s3://bucket

aws s3 helpaws s3 lshelp

EC2 Command Line Examples

awsec2 describe-instances run-instances--image-idami-xxxxx--count1

--instance-typet1.micro--key-namekeyfile stop-instances--instance-idi-xxxxxx

aws ec2 helpaws ec2 start-instanceshelp

Warmup: Get Started with Amazon

•  SkimthroughtheAWSdocumentation.•  SignupforAWSathttp://aws.amazon.com•  (SkiptheIAMmanagementfornow)• Applytheservicecredityoureceivedbyemail.• CreateanddownloadaKey-Pair,saveitinyourhomedirectory.• CreateaVMviatheAWSConsole• Connecttoyournewly-createdVMlikethis:

•  ssh-imy-aws-keypair.pemec2-user@ip-address-of-vm• CreateabucketinS3andupload/downloadsomefiles.

Demo Time http://aws.amazon.com