Java SE 9: ConDnuing to Thrive in the Cloud! · Java 9: Ahead of Time (AOT) Java Compiler 19 •...

Copyright©2016,Oracleand/oritsaffiliates.Allrightsreserved.|

JavaSE9:ConDnuingtoThriveintheCloud!

BernardTraversatVicePresidentofEngineeringJavaSEPlaKorm,OracleNov8th,2016


WhoamI?

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•  VPofEngineeringatOracle-managingtheJavaSEdevelopmentteam

–EverythingdeliveredaspartoftheJDK/JRE–EverythingdevelopedinOpenJDK

•  PreviouslyatSun,startedtoworkonJavain1998ontheJavaOSproject

•  Before,IworkedatNASAAmesonoperaDngsystemsformassivelyparallelsupercomputers


SafeHarborStatementThefollowingisintendedtooutlineourgeneralproductdirecDon.ItisintendedforinformaDonpurposesonly,andmaynotbeincorporatedintoanycontract.Itisnotacommitmenttodeliveranymaterial,code,orfuncDonality,andshouldnotberelieduponinmakingpurchasingdecisions.Thedevelopment,release,andDmingofanyfeaturesorfuncDonalitydescribedforOracle’sproductsremainsatthesolediscreDonofOracle.

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Agenda

JavaAdopDon

JavaintheCloud

JavaSE9

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JavaSEis#1withDevelopers

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•  Java8demonstratedthatwehaveovercomeandreversedoverallpercepDonofJavadecline

•  Java8adop,onisskyrocke,ng!


JavaSEis#1RunDmeintheCloud

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•  #1DeploymentrunDmeonAWSandGoogleAppEngineand#3onMSAzure

•  JavaRunDmeisthefoundaDonoftheCloudIaaS,PaaSandSaaS


WhyJavaWillConDnuetoThriveintheCloud•  Security&Vulnerability

–  SecuritybuiltdeepintheJVMrunDme(bytecodeverificaDon,managedpointers&managedmemorylayout)–  Securitybuiltinthelanguage(strongtypingandAPIencapsulaDon)–  UpcominghardwaresecurityinnovaDons(frompagestopointeraddresses,encrypDonatmemoryspeed)

•  EfficiencyandulDmateperformance–  DynamicJITcompilaDon(opDmizeandde-opDmizaDonJVMmachinery,profiledrivenopDmizaDon)–  Scalability(from1thread/coreto10,000sthreads/cores,fromafewGBstomulDpleTBs)–  CloudisallaboutuDlitycompuDng(operaDngcostwillsoondominateCloudmarket!)

•  Increasedeploymentvelocity–  Thecloudisdemandinganaccelerateddeploymentcycle(hour/day/weekvsmonth/year)–  Increasepressuretouptakenewreleases(security,criDcalfixes&performance)–managebackwardcompaDbility!!!!–  Thrivetowardsanhomogeneousanduniformsokwareinfrastructure(lowermaintenancecost)

•  Manageabilityandserviceabilityatscale–  Expressibility&Readability–  Maturetoolingecosystems–  Dynamicpatching(noservicedownDme,classredefiniDon,JVMsafepointredefine)

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ChallengestoEvolvingTheJavaPlaKorm

•  2TrillionlinesofcodeinproducDon– EnsuringbackwardcompaDbilityisabigdealtoourusers,toyouandus:-)

• Decisionsmade20yearsagomaynotapplyanymore– DualitybetweenObjectandPrimiDvetype

•  Foreseeingthefuture– Manydecisionsmadetodaymay/willhaveprofoundimpacts10yearsfromnow

• Maintainingthe“lookandfeel”ofJava

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JavaPlaKormFeatureBacklog

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UnderstandingJavaDevelopersMainPainPoints

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•  Tooverbose•  Usetoomuchmemory•  Tooslow•  Dynamicallylinked•  Etc.


MaintainingJavaCorePrinciples

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•  Consistency•  Predictability•  Easytoread•  CompaDbility


JavaSEPlaKormInvestments•  Securityisour#1priority

–  DeliverthemostsecureJavarunDmefortheCloudandnextgeneraDonhardware•  ImprovingJavadeveloperproducDvityandcompaDbility

–  MakeJavadevelopersmoreefficientandensureeasierpathtouptakenewreleasesquicker–  ProgramoncefortheCloudandscaleupasneeded

•  Increasingdensity–  ReducingmemoryusageandsharemoredatabetweenJVMprocesses–  LargestimpacttoreducingourcustomersandourcloudoperaDngcost

•  ImprovingstartupDme–  Enablinglighter-weightservicesandcontainers(microserviceandClouddevopsusecases)

•  Improvingpredictability–  Lower,morepredictableGCpauses,evenforverylargeheaps(TB+)

•  Simplifyingserviceabilityandprofiling–  ManagingandtuningJVMdeploymentsatscale


Java9“OneModular,UpgradeablePlaKormfortheCloud”


Java9JEPs

h;p://openjdk.java.net/projects/jdk9/

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102:ProcessAPIUpdates110:HTTP2Client143:ImproveContendedLocking158:UnifiedJVMLogging165:CompilerControl193:VariableHandles197:SegmentedCodeCache199:SmartJavaCompilaDon,PhaseTwo200:TheModularJDK201:ModularSourceCode211:ElideDeprecaDonWarningsonImportStatements212:ResolveLintandDoclintWarnings213:MillingProjectCoin214:RemoveGCCombinaDonsDeprecatedinJDK8215:TieredAsribuDonforjavac216:ProcessImportStatementsCorrectly217:AnnotaDonsPipeline2.0219:DatagramTransportLayerSecurity(DTLS)220:ModularRun-TimeImages221:SimplifiedDocletAPI222:jshell:TheJavaShell(Read-Eval-PrintLoop)223:NewVersion-StringScheme224:HTML5Javadoc225:JavadocSearch226:UTF-8PropertyFiles227:Unicode7.0228:AddMoreDiagnosDcCommands229:CreatePKCS12KeystoresbyDefault231:RemoveLaunch-TimeJREVersionSelecDon232:ImproveSecureApplicaDonPerformance233:GenerateRun-TimeCompilerTestsAutomaDcally235:TestClass-FileAsributesGeneratedbyjavac236:ParserAPIforNashorn237:Linux/AArch64Port238:MulD-ReleaseJARFiles240:RemovetheJVMTIhprofAgent241:RemovethejhatTool243:Java-LevelJVMCompilerInterface

244:TLSApplicaDon-LayerProtocolNegoDaDonExtension245:ValidateJVMCommand-LineFlagArguments246:LeverageCPUInstrucDonsforGHASHandRSA247:CompileforOlderPlaKormVersions248:MakeG1theDefaultGarbageCollector249:OCSPStaplingforTLS250:StoreInternedStringsinCDSArchives251:MulD-ResoluDonImages252:UseCLDRLocaleDatabyDefault253:PrepareJavaFXUIControls&CSSAPIsforModularizaDon254:CompactStrings255:MergeSelectedXerces2.11.0UpdatesintoJAXP256:BeanInfoAnnotaDons257:UpdateJavaFX/MediatoNewerVersionofGStreamer258:HarfBuzzFont-LayoutEngine259:Stack-WalkingAPI260:EncapsulateMostInternalAPIs261:ModuleSystem262:TIFFImageI/O263:HiDPIGraphicsonWindowsandLinux264:PlaKormLoggingAPIandService265:MarlinGraphicsRenderer266:MoreConcurrencyUpdates267:Unicode8.0268:XMLCatalogs269:ConvenienceFactoryMethodsforCollecDons270:ReservedStackAreasforCriDcalSecDons271:UnifiedGCLogging272:PlaKorm-SpecificDesktopFeatures273:DRBG-BasedSecureRandomImplementaDons274:EnhancedMethodHandles275:ModularJavaApplicaDonPackaging276:DynamicLinkingofLanguage-DefinedObjectModels277:EnhancedDeprecaDon278:AddiDonalTestsforHumongousObjectsinG1279:ImproveTest-FailureTroubleshooDng280:IndifyStringConcatenaDon281:HotSpotC++Unit-TestFramework282:jlink:TheJavaLinker283:EnableGTK3onLinux284:NewHotSpotBuildSystem285:Spin-WaitHints287:SHA-3HashAlgorithms289:DeprecatetheAppletAPI

•  ThebigDcketitemforjava9isModularizaDon(akaJigsaw)

• Currently121enhancements(JEPs)– 114integrated,completedandclosed– 7incandidate,proposedtodropandtargeted

• NewEAbuildavailableeveryotherweek


Java9JigsawModularity

•  JavaSE&itsimplementaDonshistoricallymonolithic– Clouddeploymentsmostokendon’trequiretheenDreplaKorm

•  BackwardcompaDbilityrequiresstrongAPIencapsulaDon• Moduleswilldefineamodule-info.javafile

– Declaresitsdependencies(requires)– Declareswhatpackagesitgivesexternalaccessto(exports)

•  SimpleExample:module com.foo.bar { requires com.foo.baz; exports com.foo.bar.alpha; exports com.foo.bar.beta; }

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Copyright©2016,Oracleand/oritsaffiliates.Allrightsreserved.|Copyright©2015,Oracleand/oritsaffiliates.Allrightsreserved.

JDK9JigsawSecurity:ModuleboundariesenforcedbytheJVM

•EncapsulateimplementaDon---internalclassesinsidemodules– SharethemwithotherimplementaDonmodulesonlyasneeded

•  Massivemaintainabilityimprovement•  SimplercompaDbilityupgradepath

•  WeandYoucannowhideandprecludeaccesstounsupportedinternalAPIsandimplementaDon

•  WillalsosignificantlyimproveSecurity•  EnabledeveloperstocreatecustomizedrunDmethatremovedunusedsecurity

sensiDveAPIs

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Copyright©2016,Oracleand/oritsaffiliates.Allrightsreserved.|Copyright©2015,Oracleand/oritsaffiliates.Allrightsreserved.

Java9:JigsawNewLinkingPhase

• Introduceanewdevelopmentphase:Linking

–AkerJavaccompilaDon,butbeforepackaginganddeployment–jlinklinkingtooltoconsumeapplicaDonclasses aswellasplaKormmodules–LinkercanproducecustomrunDmeimagesinvariousformats • Regularimages(astoday) • JVM---specificmemoryimages(CDSarchives) • “Fastexecutablebinaries”(self---containednaDveexecutablecode)

Demo

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Java9:AheadofTime(AOT)JavaCompiler

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• TheunificaDonofstaDcanddynamiccompilaDon– StaDccompilaDon–fasterstartup,lowermemoryusage,butlimitedinopDmizingcodegeneraDon

– DynamicprofilingbasedcompilaDon–slowstartupbutopDmumcodegeneraDon

• NewAOTCompilertostaDcallycompileJavaclassestonaDvesharedlibraries– ReducesstartupDmeandimprovedensitytoclosethegapagainstnaDveservice

• CompileJavapackagestonaDvesharedlibraries•  JVMwasmodifiedtoloadnaDvesharedlibrariesonstartup

–  JVMinternalstructures,whichdescribecompiledcode,aresplittodescribecompiledcodeincodecacheandinasharedlibrary

– AOTcompiledcodeisdynamicallylinkedtoJavamethodsakeritsclassisiniDalized


Java9:AheadofTime(AOT)JavaCompiler

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•  NewJDKtool‘jaotc’isaddedaspartofjavainstallaDon.‘jaotc’isjavastaDccompilerwhichproducesnaDvecodeforcompiledjavamethods.Ituseslibelfforproducing.soAOTlibraries.Touse‘jaotc’userhavetospecify.class,.jarfilesorjavamodulenameasinputandresulDngAOTlibrarynameasoutput:

jaotc--outputlibHelloWorld.soHelloWorld.class

jaotc--outputlibjava.base.so--modulejava.base

•  Usercanspecifywhichmethodstocompileorexcludewith—compile-commandsflag

jaotc--outputlibjava.base.so—compile-commandsbase.txt—modulejava.base

•  DuringJVMstartuptheAOTiniDalizaDoncodelooksforsharedlibrariesin($JAVA_HOME/lib)orlibrariesspecifiedby-XX:AOTLibraryopDon.Ifsharedlibrariesarefound,theseareloadedandused.

java-XX:AOTLibrary=./libHelloWorld.so,./libjava.base.soHelloWorld


JDK9-WhatisJShell?•  ToolprovidingadynamicinteracDonwiththeJava™programminglanguageintheCloud

• Read-Evaluate-PrintLoop(REPL)fortheJava™plaKormintheCloud– TypeinasnippetofJavacode,seetheresults

• DeeplyintegratedwithJDKtool-set– StayscurrentandcompaDble

• Also,aninteracDveAPIforusewithinotherapplicaDons

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WhatisJShellNOT?• Notanewlanguage

– “Snippets”ofpure– Nonewsyntax

• Notareplacementforthecompiler• NotanIDE

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WhowantsJShell?• NewtoJava,newtoprogramming

– Startwithexpressionsvsclasses– Immediatefeedback

•  ExploringanewAPIorlanguagefeature– Experimentandinstantlyseeresults

• PrototypingandinteracDvity– Incrementallywritecomplexcode

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WithJShell•  Typeina“snippet”ofcode•  Immediatelyseeitsbehavior

DEMO

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Java9-G1GarbageCollectorastheDefault

•  MulD-yearefforttodelivernextgeneraDonGCimprovements

•  GCpause-DmeshavethelargestimpactonapplicaDonperformance,predictabilityandresponsiveness

•  G1usesoneconDguousheapspacedividedintomanyfixedsizeregions(analogtopagesinVMOS’s)

–  Per region scalable collection process–  Sizecanbe1MB–32MB

–  NewarchitecturetoscaleuptomulD-TBheap

●  EachregioncanbeassignedauniqueevicDon/compacDonpolicy(Edenregion,Survivorregion,HumongousorOldregion)

E S

O O

O O

O O

O O O

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O O O

O H O

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H

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Eden regions

Survivor regions

Old generation regions

H Humongous regions

Available / Unused regions


•  Commercialfeaturetoreducesphysicalmemoryusageforloadedclasses•  FasterstartupDmeduetopre-loadedclassmetadata.•  SharesofclassmetadataacrossJVMprocesses.•  AppCDSstoresclassmetadatainaJavaSharedArchivefile(JSA)

–  bytecodes,fieldtables,methodtables,etc.

•  JVMwasmodifiedtoloadmoreefficientlytheseSharedArchivefiles• MulDpleJVMprocessescanmemory-mapthesameJSAfile

– MemoryintheJSAfileissharedacrossprocesses– MemoryissplitintoRead-Only(shared)andRead-Write(Copy-on-Write)

What is AppCDS?


StringDensity•  TheStringClassstorescharactersusingaUTF-16encoding(use2bytespercharacter)– But,thevastmajorityofJavaappsreallyuseonlysinglebytecharacters

• Consequence– Lotsofwastedspace/memory

•  JDK9feature(JEP254)– ModifytheJVMrunDme,JIT,GCandStringclasstotransparentlyopDmizetheinternalcharacterencoding(usesinglevsmulD-bytes)

– Requirements•  Reducememoryfootprint,yetnotsacrificethroughputperformance•  NoAPIchange,nore-compilaDonorcodemodificaDonsrequiredbyupstreamFMWorFusionAppstorealizebenefit

•  SupportonX86/x64,SPARCandLinux,Solaris,Windows,OSX

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DensityString

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•  Analyzednearly1,000’sheapprofiles–  VastmajorityofcharactersinJavaStringsaresinglebytechars

–  75%ofStringsaresmallerthan35Characters

–  75%ofCharactersareinStringsofLength<250

–  5%-20%memoryfootprintreducDonopportunityperapplicaDon

•  Specjbb2005– 21%memoryfootprintreduc,on– 27%lessGCs– 5%throughputimprovement


FlightRecorderPerformance

• BuiltintotheJVM/JDK,bythepeopledevelopingtheJVM•  Lessthat1%overheadinproducDondeployment• HighperformanceflightrecordingengineandhighperformancedatacollecDon

–  AccesstodataalreadycollectedintheJVMrunDme–  ThreadlocalnaDvebuffers–  InvariantTSCforDmestamping– Moreaccuratemethodprofiling(methodprofilingdataevenfromoutsidesafe-points)

–  FasterandmoreaccurateallocaDonprofiling

ExtremelyLowOverhead


Beyond9


TheNextBigChallenge:ObjectDatalayout

•  JavaisverygoodatopDmizingcode,lesssoatopDmizingdata– Memoryoverhead,lessthanopDmalperformance,difficulttouDlizemodernhardware

•  Java’stypesystemgivesusprimiDves,objects,andarrays– Veryflexible!Canmodelalmostanything.

•  Butflexibilityisnotexactlywhereweneedit– PrimiDvesareveryrigid– Objectsaremoreflexiblethanwealwaysneed

•  Thebigproblem:objectidenDty– Neededforpolymorphism,mutability– Notallobjectsneedit,butallobjectspayforit


ImprovedJava/NaDveInteroperability

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• BigDataHadoopandSparkarehighlydependentonnaDvelibraries–  Thesedependencieswon’tgoaway

•  OSI/0entries,GPUBLAS/LAPACK,AVX/Crypto/CRCintrinsics–  InteracDngwithNaDvelibraryfromJavaishardatbest–  JNIiscomplex,slowandhardtosecure-trueforcode,aswellasfordata

• Meanwhile,Javahassignificanttechnicaldebtsinsupportofforeigncalls–  APIsexportdatastructurelayouts(structstat)whicharehardtotraverse–  The“culturalpracDces”(likesafety)aredifferentbetweenJavaandC

• ProjectPanama-provideaneasier,saferandfasterJNI–  AddingForeignFuncDonandforeigndatasupporttoJava(FrozenArrays,VectorAPIandArrays2.0)–  AutomaDctypetranslaDon(naDvevs.carrier/javatypes)–  Nounsafe–providessafeAPIstoaccessnaDvedata/funcDons


Summary•  JavaSEadopDonisthrivingintheCloudandwillconDnue!• NeedyourhelponprovidingfeedbackonJava9

– h;ps://jdk9.java.net/download/• Beyond9,wehaveasolidtechnicalroadmap•  Let’sconDnuetoinnovateandadvancetheJavaSEPlaKormonOpenJDKtogether!

Java SE 9: ConDnuing to Thrive in the Cloud! · Java 9: Ahead of Time (AOT) Java Compiler 19 •...

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