dubbo教程高级篇第20节消息中间件在分布式系统的作用介绍mq对比来源于

、MQ、主要关注前三个（标红高高中中中中低低中高高中中中低高低低多多中多中中少少中由于ErlangLinux高43方式CJMSPerl、.net等C+（不成python、java、php、.net等库负载好有console实现无好无优点户端；缺点且对5.xActivemq不 erlang持amqpamqp的客优点用（JMS的50台左右，broker中；缺点mq中 等接的API下层MQ有多个mqnotify面mq这支持的ProtocolsThefollowingtableliststhesupportedprotocolsofeach0-8,0------------------STOMP-------InterfacesC------------Java--Java------------------------mq ark[文献MQrabbitmqkafka传统MQScenarioA:Enqueuing20,000messagesof1024byteseach,thendequeuingthemScenarioB:Enqueuinganddequeuingsimultaneously20,000messagesof1024byteseach.ScenarioC:Enqueuinganddequeuingsimultaneously200,000messagesof32bytesScenarioD:Enqueuinganddequeuingsimultaneously200messagesof32768bytesScenarioScenarioScenarioScenarioKafkavskafkarabbitmq的对比中，kafka工作是保证消息consumer是一直处于alive状态去消费消息的；broker重，需要记录很多状充分考虑消息堆积因consumer不alive状态；考虑各个角色的分布式；为追求吞吐量设broker设计较轻，不保存consumer的消提供了丰富的的exchange、bindingqueuing等modelqueue、topic等routing都topicroutingtopicrouting对应用透明的集群式但是集群对producer并不是完全透明，producer需要确认消同这一点实现了消息的顺序递交特性（partition内的消息是顺序的mirrorqueue来masterslave通过replica来支持 master/slave的可以自动切换（当master支持，但需要人工切换masterslave消息量消息量消息量。mqmetaq，metaqlinkedinkafka（scala）java版本，并对其增加了事务的支持mqmetaq3.0kafka，其擅以替代传统大部分MQ。。notify，meta2.x以前的所有队列由于mq还比较新且没有给出相应的benark而mq社区主要活跃者均国内人员，因此不便于直接对比mq和其他队列。在这里用kafka和其他队列进行对比，mq的性能比kafka还要好一些。kafkavsrabbitmqinKafkaisageneralpurposemessagebroker,likeRabbItMQ,withsimilardistributeddeploymentgoals,butwithverydifferentassumptionsonmessagemodelsemantics.Iwouldbeskepticalofthe"AMQPismoremature"argumentandlookatthefactsofhoweithersolutionsolvesyourproblem.UseKafkaifyouhaveafirehoseofevents(100k+/sec)youneeddeliveredinpartitionedorder'atleastonce'withamixofonlineandbatchconsumers,youwanttobeabletore-readmessages,youcandealwithcurrentlimitationsaroundnode-levelHA(orcanusetrunkcode),and/oryoudon'tmindsupportingincubator-levelsoftwareyourselfviaforums/IRC.UseRabbitifyouhavemessages(20k+/sec)thatneedtoberoutedincomplexwaystoconsumers,youwantper-messagedeliveryguarantees,youdon'tcareaboutordereddelivery,youneedHAatthecluster-nodelevelnow,and/oryouneed24x7paidsupportinadditiontoNeitheroffersgreat"filter/query"capabilities-ifyouneedthat,considerusingStormontopofoneofthesesolutionstoaddcomputation,filtering,querying,onyourstreams.OrusesomethinglikeCassandraasyourqueryablecache.Kafkaisalsodefiniynot"mature"eventhoughitis"productionready".Details(caveat-myopinion,I'venotusedeitheringreatanger,andIhavemoreexposuretoFirstly,onRabbitMQvs.Kafka.Theyarebothexcellentsolutions,RabbitMQbeingmoremature,butbothhaveverydifferentdesignphilosophies.Fundamentally,I'dsayRabbitMQisbroker-centric,focusedarounddeliveryguaranteesbetweenproducersandconsumers,withtransientpreferredoverdurablemessages. WhereasKafkaisproducer-centric,basedaroundpartitioningafirehoseofeventdataintodurablemessagebrokerswithcursors,supportingbatchconsumersthatmaybeoffline,oronlineconsumersthatwantmessagesatlowlatency.RabbitMQusesthebrokeritselftomaintainstateofwhat'sconsumed(viaacknowledgements)-itusesErlang'sMnesiatomaintaindeliverystatearoundthebrokercluster.Kafkadoesn'thavemessageacknowledgements,itassumestheconsumertracksofwhat'sbeenconsumedsofar.BothKafkabrokers&consumersuseZookeepertoreliablymaintaintheirstateacrossacluster.RabbitMQpresumesthatconsumersaremostlyonline,andanymessages"inwait"(persistentornot)areheldopaquely(i.e.nocursor).RabbitMQpre-2.0(2010)wouldfalloverifyourconsumersweretooslow,butnowit'srobustforonlineandbatchconsumers-butclearlylargeamountsofpersistentmessagessittinginthebrokerwasnotthemaindesigncaseforAMQPingeneral.Kafkawasbasedfromthebeginningaroundbothonlineandbatchconsumers,andalsohasproducermessagebatching-it'sdesignedforholdinganddistributinglargevolumesofRabbitMQprovidesrichroutingcapabilitieswithAMQP0.9.1'sexchange,bindingandqueuingmodel.Kafkahasaverysimpleroutingapproach-inAMQPparlanceitusestopicexchangesBothsolutionsrunasdistributedclusters,butRabbitMQ'sphilosophyistomaketheclustertransparent,asifitwereavirtualbroker.Kafkamakesitexplicit,byforcingtheproducertoknowitispartitioningatopic'smessagesacrossseveralnodes,thishasthebenefitofpreservingordereddeliverywithinapartition,whichisricherthanwhatRabbitMQexposes,whichisalmostalwaysunordereddelivery(theAMQP0.9.1modelsays"oneproducerchannel,oneexchange,onequeue,oneconsumerchannel"isrequiredforin-orderdelivery).Putanotherway,Kafkapresumesthatproducersgenerateamassivestreamofeventsontheirowntimetable-there'snoroomforthrottlingproducersbecauseconsumersareslow,sincethedataistoomassive.ThewholejobofKafkaistoprovidethe"shockabsorber"betweenthefloodofeventsandthosewhowanttoconsumethemintheirownway--someonline,othersoffline-onlybatchconsumingonanhourlyorevendailybasis.Kafkacandeliver"atleastonce"semanticsperpartition(sincemaintainsdeliveryorder),justlikeRabbitMQ,butitdoesitinaverydifferentway.Performance-wise,ifyourequireordereddurablemessagedelivery,currentlyitlookslikethere'snocomparison:KafkacurrentlyblowsawayRabbitMQintermsofperformanceonsyntheticbenarks.Thispaperindicates500,000messagespublishedpersecondand22,000messagesconsumedpersecondona2-nodeclusterwith6-diskRAID/en...OfcoursethiswaswrittenbytheLinkedInguyswithoutnecessarilyexpertRabbitMQinput,soFinally,a KafkaisanearlyApacheincubator Itdoesn'tnecessarilyhavethehard-learnedaspectsinNow,awordonAMQP.Frankly,itseemsthestandardisamess.Officiallythereisa1.0proposedspecificationthatisgoingthroughtheOASISstandardsprocess.InpracticeitisaAsetofgenerallyavailable,widely-adopted,production-qualityAMQP1.0implementationsacrossthemajorreleases(QpidfromRedhat,RabbitMQ,etc.)won'texistuntil2013,ifever.Asanexternalobserverwithnoinsideknowledge,hereiswhatitlookslike:theworkinggroupspent5yearsonaspec,from2003to2008,culminatinginawidelyadoptedrelease(0.9.1).Thenasubsetofmorepowerfulworkinggroupmembersrewrotethespecbylate2011,compleyshiftingthefocusofthespecfromamessagingmodeltoatransportprotocol(sortoflikeTCP++),anddeclaredit1.0.So,wehavethestrangecasewherethe"mature"AMQPisthenon-standard0.9.1specificationandthe"immature"AMQPistheactual1.0standard.Thisisn'ttosuggest1.0isn'tgoodtechnology,itlikelyis,butthatit'samuchlower-levelspecthanAMQPintendedtobeformostofitspublishedlife,andisnotwidelysupportedyetbeyondprototypesando