CQRS+EventSourcingをAkka Persistenceを使って実装してみる

CQRS+EventSourcingをAkka Persistenceを使って実装してみる

Transcript

1. CQRS+EventSourcingΛAkka Persistence Λ࢖࣮ͬͯ૷ͯ͠ΈΔɻʙίπͱϋϚΓϙΠϯτʙ 2016/03/16 Reactive Messaging PatternsϓϨಡॻձ - CQRSɺESͷجຊΛֶͿ - Satoshi Matsushita
2. ࣗݾ঺հ • Satoshi Matsushita @satoshi_m8a • Scala, Akka, DDD, ϑϩϯτΤϯυ, ίϯϐϡʔλϏδϣϯ, ػցֶश • ήώϧϯגࣜձࣾ
 ɹ Python, Go, Erlang, Scala, OCaml, TypeScript 
 ʮGehirn Infrastructure Servicesʯ
 ηΩϡϦςΟ਍அ • ECͷγεςϜΛAkka PersistenceΛ࢖ͬͯ։ൃ͍ͯͨ͠ɻ
3. Akka + DDD ؾӡͷߴ·Γ(1) • Scala Matsuri 2016 ೋ೔໨ΞϯΧϯϑΝϨϯε
 
 DDD+CQRS+EventSourcing࣮૷͢Δձ
 (AkkaύϑΥʔϚϯενϡʔχϯάʹ͍ͭͯ࿩ͯ͠ΈΑ͏ձ) by ͔ͱ͡ΎΜ͞Μ(@j5ik2o)
4. Akka + DDD ؾӡͷߴ·Γ(2) • Vaughn Vernon ࢯͷॻ੶
5. Akka + DDD ؾӡͷߴ·Γ(3) • LightbendͷҰ؏ͨ͠πʔϧΩοτ • DDDΛҙࣝͨ͠΋ͷ
 Akka Persistence
 Akka Persistence Query
6. Akka + DDD ؾӡͷߴ·Γ(4) • Lagom
 ɹϚΠΫϩαʔϏεΛߏங͢ΔͨΊͷϑϨʔϜϫʔΫ
 ɹCQRS+ES͕ϕʔεʹͳ͍ͬͯΔ
7. Akka + DDD ؾӡͷߴ·Γ(5) • ϚΠΫϩαʔϏεԽͷྲྀΕ • ϦΞΫςΟϒͱ͍͏ߟ͑ํͷ޿·Γ
8. ໨࣍ • CQRS • Πϕϯτιʔγϯά • ίϚϯυαΠυ • ΫΤϦαΠυ • ࢀߟ
9. CQRS
 Command Query Responsibility Segregation ίϚϯυɾΫΤϦ੹຿෼཭
10. Α͋͘Δ֊૚Խύλʔϯ ϓϨθϯςʔγϣϯ૚ ΞϓϦέʔγϣϯ૚ υϝΠϯ૚ ΠϯϑϥετϥΫνϟ૚
11. CQRS֓೦ਤ ϓϨθϯςʔγϣϯ૚ ΞϓϦέʔγϣϯ૚ υϝΠϯ૚ ΠϯϑϥετϥΫνϟ૚ σʔλΞΫηε૚ ίϚϯυαΠυ ΫΤϦαΠυ
12. υϝΠϯϞσϧ • ྫɿTwitterͷϑΥϩϫʔ / ϑΥϩΠʔ Ϣʔβʔ ϑΥϩϫʔͷϦετ ϑΥϩΠʔͷϦετ ϒϩοΫϦετ
13. υϝΠϯϞσϧ • ϑΥϩʔ͢Δͱ͍͏ৼΔ෣͍ʹண໨͢Δͱ Ϣʔβʔ
 ϑΥϩʔ͢Δ(userId) ϒϩοΫ͞ΕΔ(userId) ϑΥϩΠʔͷϦετ ϒϩοΫ͞Ε͍ͯΔ ϢʔβʔͷϦετ
14. CQRS Ϣʔβʔ ϑΥϩΠʔͷϦετ ϒϩοΫ͞Ε͍ͯΔ ϢʔβʔͷϦετ ίϚϯυαΠυ ΫΤϦαΠυ ϑΥϩϫʔͷϦετ ϑΥϩΠʔͷϦετ ϒϩοΫ͞Ε͍ͯΔ ϢʔβʔͷϦετ ϒϩοΫ͍ͯ͠Δ ϢʔβʔͷϦετ … ϢʔβʔͷϦετ
15. ෳࡶ͞ʹཱͪ޲͔͏ • ෳࡶͳυϝΠϯΛɺͦͷ··ෳࡶͳυϝΠϯϞσϧ ʹམͱͯ͠ຬ଍͕ͪ͠ • ·ͣ͸ɺίϯςΩετ෼ׂΛݕ౼ • υϝΠϯΛΑ͘؍࡯͠ɺৼΔ෣͍ʹϑΥʔΧε͢Δ • CQRS΍ESͷݕ౼͸ͦͷ͋ͱ
16. Event Sourcing
17. Event Sourcing ΧʔτID ɿ “cart1” ঎඼ɿ “A”->0, “B”->1 Χʔτ࡞੒ ঎඼AΛ௥Ճ ঎඼BΛ௥Ճ ঎඼AΛ࡟আ ΧʔτID ɿ “cart1” ঎඼ɿ “A”->1, “B”->0
18. Snapshot 1 2 Snapshot 101 100 • શͯͷΠϕϯτΛॳΊ͔Β෮ݩ͍ͯͯ͠ ͸͕͔͔࣌ؒΔ • εφοϓγϣοτΛͱ్ͬͯத͔Β෮ݩ
19. CQRS+ES ίϚϯυαΠυ ΫΤϦαΠυ Journal Aggregate Root Command Service Projection DAO Query Service DB DB Command Domain Event Domain Event DTO DTO Polling
20. σʔλϕʔεબ୒ͷϙΠϯτ • ίϚϯυαΠυ
 ɹɾCassandra, DynamoDB, Riak
 ɹɾॻ͖ࠐΈΛεέʔϧͰ͖Δ΋ͷɺՄ༻ੑͷߴ͍΋ͷ͕ྑ͍ • ΫΤϦαΠυ
 ɹɾ֤छRDB, NoSQL(υΩϡϝϯτࢦ޲ɾάϥϑࢦ޲)
 ɹɾΫΤϦʹڧ͍΋ͷ͕ྑ͍
 ɹɾ૊Έ߹ΘͤOK
21. Materialized View Pattern • ίϚϯυαΠυͷDB͕ਖ਼ͷσʔλΛอ࣋͢Δɺ
 ΫΤϦαΠυ͸ͦΕͷView • ϦʔυϨϓϦΧͷߏஙʢಡΈࠐΈΛεέʔϧʣ https://msdn.microsoft.com/ja-jp/library/dn589782.aspxɹ͔ΒҾ༻
22. αʔϏε౷߹΋༰қ • ৽͍͠αʔϏεΛ௥Ճͨ͠ΒɺυϝΠϯΠϕϯτΛྲྀ ͠ࠐΉɻ • ͔͋ͨ΋ɺͦͷ৽͍͠αʔϏε͕࠷ॳ͔Β౷߹͞Εͯ Δ͔ͷΑ͏ʹৼΔ෣͏ɻ • ݱࡏͷΠϕϯτ·Ͱ௥͍͍ͭͨΒɺγεςϜʹೃછΜ Ͱ͍Δɻ
23. ݁Ռ੔߹ੑ ίϚϯυαΠυ ΫΤϦαΠυ Journal Aggregate Root Command Service Projection DAO Query Service DB DB Command Domain Event Domain Event DTO DTO Polling
24. Over Kill • ྫɿIDɺ໊લɺύεϫʔυɺE-MailΞυϨεΛ࣋ͭɺ
 ձһAR • ύεϫʔυ΍E-MailΞυϨεͷมߋཤྺΛ௥͏͜ͱ ͰɺϏδωεͷՁ஋ΛੜΉͷ͔ʁ • CQRS͚ͩɺ΋͘͠͸୯७ͳCRUD͕Ͱ͖Δ͚ͩͰΑ ͍ͷͰ͸ʁ
25. ༨ஊɿ७ਮͳREST API͸DDDʹ޲͔ͳ͍ • REST APIͰҰ୴গͳ͘ͳͬͨ৘ใΛ෮ݩ͢Δͷ͸ࠔ೉ • ७ਮͳRESTʹͩ͜ΘΒͳ͍ɻ
 CQRSͰ࡞ͬͨં֯ͷϦονͳίϚϯυϞσϧ͕ҙຯΛͳ͞ͳ͘ͳΔɻ ۀ຿Ͱൃੜ͢Δૢ࡞ ৘ใྔɿେ REST API ৘ใྔɿখ ϦονͳίϚϯυϞσϧ ৘ใྔɿେ ʼ ʻ ×
26. ESͷϝϦοτɾσϝϦοτ • ɹϝϦοτ
 ΠϯϐʔμϯεϛεϚον͕ͳ͍ɻ
 ཤྺ؅ཧ͕ෆཁɺσʔλղੳ΍σόοάʹ΋࢖͑Δɻ
 Πϕϯτ͸௥هͷΈͳͷͰύϑΥʔϚϯε͕ྑ͍ɻ
 ػೳ௥Ճ΋༰қɻ • ɹσϝϦοτ
 Πϕϯτͷमਖ਼͕൥ࡶ(ޙड़)
 σʔλαΠζͷ໰୊
27. CQRS+ESͷϝϦοτɾσϝϦοτ • ɹϝϦοτ
 υϝΠϯͷৼΔ෣͍͕໌֬ʹͳΔ
 ViewΛॊೈʹͭ͘ΕΔ
 εέʔϧ΋ॊೈʹ • ɹσϝϦοτ
 ݁Ռ੔߹ੑ
28. AkkaͰ࡞Δ CQRS+ES ίϚϯυαΠυ ΫΤϦαΠυ Journal Aggregate Root Command Service Projection DAO Query Service DB DB Command Domain Event Domain Event DTO DTO Polling Akka Persistence Akka Persistence Plugin Akka Persistence Query Slick3 Akka Cluster Sharding
29. ίϚϯυαΠυ
30. Akka Persistence • Actorͷ಺෦ঢ়ଶΛӬଓԽ͢Δ͜ͱ͕Ͱ͖Δ • AkkaͷCQRSͱΠϕϯτιʔγϯάʹ࢖ΘΕΔ • ϝοηʔδͷ࠶ૹͷ࢓૊Έ΋ఏڙʢAt least once deliveryʣ
31. ྫɿΧ΢ϯτ͢ΔActor • CounUpίϚϯυΛड͚औΓɺ಺෦ͷΧ΢ϯτΛ૿ Ճ͍ͤͯ͘͞ɻ
32. PersistentActor Persistent Actor Journal persistenceId = “c100” count = 0 CountUp CountIncreased Ack(ӬଓԽ׬ྃ) • ίϚϯυΛड͚෇͚ɺυϝΠϯΠϕϯτΛൃߦ͢Δɻ ᶃ ᶄ ᶅ
33. PersistentActor Persistent Actor Journal persistenceId = “c100” count = 1 Ack ᶆ Ack ᶇ • Journal͔ΒͷAckΛ଴ͪɺ಺෦ঢ়ଶΛߋ৽͢Δ
34. ϙΠϯτ • ಺෦ঢ়ଶ(count)ͷߋ৽͸υϝΠϯΠϕϯτͷӬଓԽ ׬ྃΛ଴͔ͬͯΒߦ͏ • ӬଓԽ͞Ε͍ͯͳ͍Πϕϯτ͸ى͍ͬͯ͜ͳ͍Πϕ ϯτͱಉٛ
35. PersistentActorͷ෮ݩ • ΫϥογϡɺλΠϜΞ΢τ࣌ͷఀࢭɺγϟʔυͷҠ ಈͳͲ༷ʑͳཧ༝ͰActor͸࠶ىಈ͢Δɻ • ࠶ىಈͨ͠ActorΛݩͷঢ়ଶʹ໭͠ɺίϚϯυΛड ͚෇͚͍ͨɻ
36. PersistentActorͷ෮ݩ Persistent Actor Journal persistenceId = “c100” count = 3 CountIncreased ᶃ ᶄ CountIncreased CountIncreased Select Events where persistenceId = “c100” ᶅ
37. Akka Persistence class CountUpActor extends PersistentActor {
 override def persistenceId: String = self.path.name
 
 context.setReceiveTimeout(120.seconds)
 
 var count: Int = 0
 
 def updateState(event: Increased) = {
 this.count = this.count + event.amount
 }
 
 override def receiveRecover: Receive = {
 case e: Increased =>
 updateState(e)
 }
 
 override def receiveCommand: Receive = {
 case c: CountUp =>
 persist(Increased(c.amount)) {
 event =>
 updateState(event)
 sender() ! event
 }
 case ReceiveTimeout =>
 context.parent ! Passivate(stopMessage = Stop)
 case Stop =>
 context.stop(self)
 }
 } <- ͜͜ͰӬଓԽ <- ӬଓԽ͕ऴΘͬͨޙʹঢ়ଶΛߋ৽ <- ෮ݩͨ͠ΠϕϯτΛݩʹঢ়ଶΛߋ৽
38. ϙΠϯτ • Recovery͕׬ྃ͢Δ·ͰɺίϚϯυΛॲཧ͠ͳ͍Α ͏ʹͳ͍ͬͯΔɻ • Recovery࣌͸಺෦ঢ়ଶͷߋ৽͚ͩΛߦ͏ɺ
 ֎෦΁ίϚϯυ΍ϝοηʔδΛൃߦͯ͠͸ͳΒͳ ͍ɻ
39. Aggregate Root • ࣮ࡍ͸PersistentActorΛܧঝͯ͠ɺAggregateRoot ΞΫλʔΛ࡞Δͱྑ͍ɻ(c.f. akka-ddd)
 https://github.com/pawelkaczor/akka-ddd/blob/master/akka-ddd-core/src/main/scala/pl/newicom/dddd/ aggregate/AggregateRoot.scala • εφοϓγϣοτૢ࡞, GracefulPassivation, 
 ϦΧόϦΛӅṭ
40. υϝΠϯΠϕϯτͷઃܭ • υϝΠϯΠϕϯτ͸ىͬͨ͜ࣄ࣮Λද͢ɻ
 Πϕϯτ໊͸աڈܗ (Increased, Decresed, Created) • ʮॅॴΛมߋ͠·ͨ͠ʯ vs ʮҾͬӽ͠·ͨ͠ʯ • ʮچγεςϜ͔ΒσʔλΛҠߦ͠·ͨ͠ʯΠϕϯτ • ͖͔͚ͬͱͳͬͨίϚϯυΛΠϕϯτͷϝλσʔλͱͯ͠อ࣋͢Δ͜ͱ΋ • ཻ౓͸ࡉ͔͗ͯ͢΋ྑ͘ͳ͍ɻ
 e.g.ʮ༣ศ൪߸Λมߋ͠·ͨ͠ʯ
41. υϝΠϯΠϕϯτͷγϦΞϥΠζ • υϝΠϯΠϕϯτ͸γϦΞϥΠζ͞Εͯɺ
 ίϚϯυαΠυͷDBʹอଘ͞ΕΔɻ • σϑΥϧτͰ͸JavaͷγϦΞϥΠβ͕࢖ΘΕΔ • JavaͷγϦΞϥΠβ͸଎౓໘Ͱ΋ɺ֦ு໘Ͱ΋໰୊͕͋Δ • ࣮ӡ༻͢ΔͷͰ͋Ε͹ɺ Google Protocol Buffers ͕ແ೉
42. υϝΠϯΠϕϯτͷεΩʔϚมߋ • ϑΟʔϧυΛ௥Ճͨ͠ΓɺҰͭͷΠϕϯτΛ෼ׂͳͲ • EventAdapterΛ࢖ͬͨΓɺҰԠͷղܾํ๏͸͋Δ͕൥ࡶ • Stamina
 ɹhttps://github.com/scalapenos/stamina
43. Persistence Plugin • Cassandra, JDBC, DynamoDB, Riak ޲͚ͷPlugin • ςετ༻ͷInMemory Plugin΍ LevelDB Plugin • ReadJournal API(ޙड़)ͷ࣮૷͠΍͍͢DB͕͓͢͢Ί • Cassandra Plugin͸Akkaެࣜ
44. ΫΤϦαΠυ
45. Akka Persistence Query • CQRSͷΫΤϦαΠυͷ࣮૷ʹ࢖ΘΕΔ • ΫΤϦαΠυશମͰ͸ͳ͘ɺ
 Journal͔ΒΫΤϦଆͷDB΁ͷ౤Өʹ࢖ΘΕΔ • experimental (Akka 2.4.2)
 Plugin΋ग़ἧ͍ͬͯͳ͍
46. Journal Projection DAO DB Domain Event DTO Polling ΫΤϦαΠυ DTO • Read Journal APIΛ࣮૷ͨ͠Persistence Plugin Λ࢖͏ • JournalΛPollingͯ͠ɺυϝΠϯΠϕϯτΛ଴ͪड͚Δ
47. ReadJournal API • EventsByTagQuery
 ɹλάΛݩʹΠϕϯτΛऔಘ • EventsByPersistenceIdQuery
 ɹPersistenceIdΛݩʹΠϕϯτΛऔಘɹ • AllPersistenceIdsQuery
 ɹ͢΂ͯͷPersistenceIdΛऔಘ • CurrentPersistenceIdsQuery
 ɹݱࡏଘࡏ͢ΔશͯͷPersistenceIdΛऔಘʢϙʔϦϯάͳ͠ʣ • ͢΂ͯͷJournal Plugin͕͜ΕΒ࣮૷͍ͯ͠ΔΘ͚Ͱ͸ͳ͍
 ɹ࣮૷͕ࠔ೉ͳ΋ͷ΋͋ΔͷͰɺJournal༻ͷDBબͼ͸৻ॏʹ
48. ΠϕϯτʹλάΛ෇༩͢Δ class ThreadEventAdapter extends WriteEventAdapter {
 
 override def manifest(event: Any): String = ""
 
 val tags = Set("Thread")
 
 override def toJournal(event: Any): Any = event match {
 case e: ThreadEvent =>
 Tagged(event, tags)
 case _ =>
 event
 }
 }

49. Projection • Read Model Projection / Read Model Updaterͱ΋͍͏ • υϝΠϯΠϕϯτΛݩʹɺViewΛߏங͢Δ
50. Projection 
 val readJournal = PersistenceQuery(system)
 .readJournalFor[LeveldbReadJournal](LeveldbReadJournal.Identifier)
 implicit val mat = ActorMaterializer()(system)
 
 val dao = new ThreadsDao(dbConfig)
 
 val projection = new ThreadProjection(dao)
 
 readJournal
 .eventsByTag("Thread", projection.lastOffset)
 .mapAsync(1) { envelope =>
 projection.update(envelope.event).map(_ => envelope.offset)
 }
 .mapAsync(1) { offset => projection.saveProgress(offset) }
 .runWith(Sink.ignore)
 

51. ΫΤϦ • Slick3ͳͲΛ࢖ͬͯΫΤϦ͢Δɻ
52. ͦͷଞ • Process Manager
 ෳ਺ͷAggregate Rootʹ·͕ͨͬͨॲཧΛॱং ྑ࣮͘ߦ͢Δ
 ɹPersistentFSMΛ࢖͏ɻ • Cluster Sharding
 ɹAggregate RootΛ෼ࢄͤ͞Δɻ
 ɹCluster Singleton
53. ·ͱΊ • CQRS+ESͷίϚϯυαΠυͱΫΤϦαΠυΛ
 Akka Persistenceͱ Akka Persistence QueryͰ࣮૷ ͨ͠ • Lagom
54. ࢀߟ • CQRS Journey
 https://msdn.microsoft.com/ja-jp/library/jj554200.aspx • .NETͷΤϯλʔϓϥΠζΞϓϦέʔγϣϯΞʔΩςΫνϟ • ࣮ફυϝΠϯۦಈઃܭ
55. Reactive Messaging Patterns with the Actor Model ಡॻձ ڵຯͷ͋Δํ͸͓੠͕͚͍ͩ͘͞ɻ
56. ͋Γ͕ͱ͏͍͟͝·ͨ͠