vert.x: microservices were never so easy (clement escoffier)
TRANSCRIPT
VERT.XMICROSERV ICES WERE NEVER SOEASY
CLEMENTESCOFFIER
Vert.xCoreDeveloper,RedHat
VERT.XI N 1 0 SL IDES . . .
VERT.X I S A TOOLK IT TO BU I LDDISTR IBUTED AND REACT IVEAPPL ICAT IONS ON TOP OF THE JVMUS ING AN ASYNCHRONOUS NON-BLOCK ING DEVELOPMENT MODEL .
TOOLKITVert.xisaplainboringjarVert.xcomponentsareplainboringjarsYourapplicationdependsonthissetofjars(classpath,fat-jar,...)
TOOLKITTheseslidesareservedbyavert.xapplication:
executedonOpenshiftpackagedasafatjar
vertx-core:themainvert.xcomponentvertx-web:acomponenttobuildmodernwebapplicationsvertx-hazelcast:animplementationofthevert.xclustermanagervertx-service-discovery-bridge-kubernetes:anextensiontointeractwithKubernetes
DISTRIBUTED
DISTRIBUTED“ Youknowyouhaveadistributedsystemwhenthecrashofacomputeryou'veneverheardsofstopsyoufromgettinganyworkdone.(LeslieLamport)
REACTIVEReactivesystemsare
Responsive-theyrespondinanacceptabletimeElastic-theyscaleupanddownResilient-theyaredesignedtohandlefailuresgracefullyAsynchronous-theyinteractusingasyncmessages
http://www.reactivemanifesto.org/
REACTIVE“ "Moore'slaw"istheobservationthat,overthehistoryofcomputinghardware,thenumberoftransistorsinadenseintegratedcircuithasdoubledapproximatelyevery2years.
Unfortunately,nofreelunchanymore...
REACTIVECPUmanufacturerscannotgetasingle-coreCPUtogoanyfaster
Multi-coreProcessorsRequireparallelexecutionRequireadifferentwaytodesign,developandexecutesoftwareReactivesystemsisonesolutiontothisissue
POLYGLOTVert.xapplicationscanbedevelopedusing
JavaGroovyRuby(JRuby)JavaScript(Nashorn)Ceylon
MICROSERVICESREBRAND INGD ISTR IBUTEDAPPL ICAT IONS
MICROSERVICES“ Themicroservicearchitecturalstyleisanapproachtodevelopingasingleapplicationasasuiteofsmallservices,eachrunninginitsownprocessandcommunicatingwithlightweightmechanisms,oftenanHTTPresourceAPI.Theseservicesarebuiltaroundbusinesscapabilitiesandindependentlydeployablebyfullyautomateddeploymentmachinery.Thereisabareminimumofcentralizedmanagementoftheseservices,whichmaybewrittenindifferentprogramminglanguagesandusedifferentdatastoragetechnologies.(MartinFowler)
ASUITEOFINDEPENDENTSERVICES:Eachservicerunsinitsownprocess
Sotheyaredistributedapplications
Lightweightinteractions-Loose-coupling
NotonlyHTTPMessagingStreams(async)RPC
ASUITEOFINDEPENDENTSERVICES:Independentlydeveloped,testedanddeployed
Automatedprocess(Liskov)substitutability
It'sallaboutagility
AgilityofthecompositionYoucanreplaceanymicroserviceYoucandecidewhouseswho
SORRY...NOFREELUNCHDistributedapplicationsarehard
fail(fail-stop,byzantinefault)DiscoverabilityissueReliabilityissueAvailabilityissue
Howtokeepthingsontrack
MonitoringHealthTracing...
COMPLEXITYGROWTH
VERT.X&MICROSERVICESWewont'buildregularmicroservices,butreactivemicroservices
Responsive-fast,isabletohandlealargenumberofevents/connectionsElastic-scaleupanddownbyjuststartingandstoppingnodes,round-robinResilient-failureasfirst-classcitizen,fail-overAsynchronousmessage-passing-asynchronousandnon-blockingdevelopmentmodel
ASYNCHRONOUS&NON-BLOCKING
WHATDOESVERT.XPROVIDETOBUILDMICROSERVICES?TCP,UDP,HTTP1&2serversandclients(non-blocking)DNSclientEventbus(messaging)DistributeddatastructuresLoad-balancingFail-overServicediscoveryFailuremanagement,Circuit-breakerShell,Metrics,Deploymentsupport
HTTP&RESTBECAUSE I T ALWAYSBEG IN W ITH A REST
VERT.XHELLOWORLDvertx.createHttpServer() .requestHandler(request -> { // Handler receiving requests request.response().end("World !"); }) .listen(8080, ar -> { // Handler receiving start sequence completion (AsyncResult) if (ar.succeeded()) { System.out.println("Server started on port " + ar.result().actualPort()); } else { ar.cause().printStackTrace(); } });
VERT.XHELLOWORLDInvoke
EVENT LOOPS
VERT.XASYNCHTTPCLIENTHttpClient client = vertx.createHttpClient( new HttpClientOptions() .setDefaultHost(host) .setDefaultPort(port));
client.getNow("/", response -> { // Handler receiving the response
// Get the content response.bodyHandler(buffer -> { // Handler to read the content });});
SERVICEDISCOVERYLocatetheservices,environment-agnostic
SERVICEDISCOVERY-KUBERNETESNoneedforpublication-ImportKubernetesservices
HttpEndpoint.getClient(discovery, new JsonObject().put("name", "vertx-http-server"), result -> { if (result.failed()) { rc.response().end("D'oh no matching service"); return; } HttpClient client = result.result(); client.getNow("/", response -> { response.bodyHandler(buffer -> { rc.response().end("Hello " + buffer.toString()); }); }); });
CHAINEDHTTPREQUESTS
Invoke
INTERACTINGWITHBLOCKINGSYSTEMS
MESSAGINGWITHTHEEVENTBUSTHE SP INE OF VERT . X
APPL ICAT IONS
THEEVENTBUSTheeventbusisthenervoussystemofvert.x:
Allowsdifferentcomponentstocommunicateregardlesstheimplementationlanguageandtheirlocationwhethertheyrunonvert.xornot(usingbridges)
Address:MessagesaresenttoanaddressHandler:Messagesarereceivedinhandlers.
POINTTOPOINT
PUBLISH/SUBSCRIBE
REQUEST/RESPONSE
DISTRIBUTEDEVENTBUSAlmostanythingcansendandreceivemessages
DISTRIBUTEDEVENTBUSLet'shaveajava(Vert.x)app,andanodeappsendingdatajusthere:
hellofromjava(8321)
hellofromjava(8320)
hellofromjava(8319)
hellofromjava(8318)
hellofromjava(8317)
hellofromjava(8316)
hellofromjava(8315)
hellofromjava(8314)
hellofromjava(8313)
DISTRIBUTEDEVENTBUS
EVENTBUSCLIENTSANDBRIDGESClients:
SockJS:browser,node.jsTCP:everysystemabletoopenaTCPsocketGo:forsystemdevelopinGo
Bridges:
StompAMQPCamel
RELIABILITYPATTERNS
DON 'T BE FOOL , BEPREPARED TO FA IL
RELIABILITYIt'snotaboutbeingbug-freeorbulletproof,it'simpossible.
It'saboutbeingpreparedtofail,andhandlingthesefailures.
MANAGINGFAILURESDistributedcommunicationmayfail
vertx.eventbus().send(..., ..., new DeliveryOptions().setSendTimeout(1000), reply -> { if (reply.failed()) { System.out.println("D'oh, he did not reply to me !"); } else { System.out.println("Got a mail " + reply.result().body()); }});
MANAGINGFAILURES
Invoke
MANAGINGFAILUREclient.get("/", response -> { response .exceptionHandler(t -> { // If the content cannot be read rc.response().end("Sorry... " + t.getMessage()); }) .bodyHandler(buffer -> { rc.response().end("Ola " + buffer.toString()); }); }) .setTimeout(3000) .exceptionHandler(t -> { // If the connection cannot be established rc.response().end("Sorry... " + t.getMessage()); }) .end();
MANAGINGFAILURE
Invoke
CIRCUITBREAKER
CIRCUITBREAKERcb.executeWithFallback(future -> { // Async operation client.get("/", response -> { response.bodyHandler(buffer -> { future.complete("Ola " + buffer.toString()); }); }) .exceptionHandler(future::fail) .end(); },
// Fallback t -> "Sorry... " + t.getMessage() + " (" + cb.state() + ")") // Handler called when the operation has completed .setHandler(content -> /* ... */);
CIRCUITBREAKER
Invoke
SCALABILITYPATTERNS
BE PREPARED TO BEFAMOUS
BALANCINGTHELOADWhenseveralconsumerslistentothesameaddress,Vert.xdispatchesthesentmessagesusingaroundrobin.
So,toimprovethescalability,justspawnanewnode!
BALANCINGTHELOAD
BALANCINGTHELOADInvoke
SCALINGHTTP
THISISNOTTHEEND()
BUTTHEFIRSTSTEPONTHEREACTIVEMICROSERVICEROAD
HOWTOSTART?http://vertx.iohttp://vertx.io/blog/posts/introduction-to-vertx.htmlhttp://vertx-lab.dynamis-technologies.comhttps://github.com/vert-x3/vertx-examples
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