[axon] snapshot - clone coding

이전글: 2022.01.12 - [개발/spring] - [axon] command/query project 생성 - clone coding

[axon] command/query project 생성 - clone coding

이전 글에 이어서 axon framework의 command에 대한 클론 코딩을 이어가던 중 실습 내용에 대한 고찰을 해본다.

참고)

	필수 어노테이션
command	@TargetAggregateIdentifier
aggregate	@Aggregate @AggregateIdentifier

 

클론 코딩 참고 블로그는 아래와 같다: https://cla9.tistory.com/12?category=814447 

8. Command 어플리케이션 구현 - 3

따라해본다.

POST http://localhost:8080/holder
POST http://localhost:8080/account
POST http://localhost:8080/deposit
POST http://localhost:8080/withdrawal
POST http://localhost:8080/withdrawal
POST http://localhost:8080/withdrawal

위 글에도 써있지만 아래와 같은 순서로 잔고를 인출했을 때의 로그는 아래와 같다(withdrawal을 10원씩 4번째 호출했을 때이다).

다시 말하지만 api 한번 호출 시의 로그이다.

[nio-8080-exec-3] o.a.commandhandling.SimpleCommandBus     : Handling command [com.cqrs.command.commands.WithdrawMoneyCommand]
[nio-8080-exec-3] o.a.m.unitofwork.AbstractUnitOfWork      : Starting Unit Of Work
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.AbstractUnitOfWork$$Lambda$1197/0x00000008008b5040 for phase ROLLBACK
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase STARTED
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.UnitOfWork$$Lambda$1201/0x00000008008b4040 for phase COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.UnitOfWork$$Lambda$1202/0x00000008008b4440 for phase ROLLBACK
[nio-8080-exec-3] o.a.a.c.event.axon.AxonServerEventStore  : Reading events for aggregate id 2b158c88-b810-4643-9db4-4096edea5621
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : >> applying AccountCreationEvent(holderID=76147ef5-280f-439e-b017-bcd04028f176, accountID=2b158c88-b810-4643-9db4-4096edea5621)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : applying DepositMoneyEvent(holderID=76147ef5-280f-439e-b017-bcd04028f176, accountID=2b158c88-b810-4643-9db4-4096edea5621, amount=300)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : balance 300
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=76147ef5-280f-439e-b017-bcd04028f176, accountID=2b158c88-b810-4643-9db4-4096edea5621, amount=10)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : balance 290
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=76147ef5-280f-439e-b017-bcd04028f176, accountID=2b158c88-b810-4643-9db4-4096edea5621, amount=10)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : balance 280
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=76147ef5-280f-439e-b017-bcd04028f176, accountID=2b158c88-b810-4643-9db4-4096edea5621, amount=10)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : balance 270
[nio-8080-exec-3] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[ault-executor-3] o.a.a.c.e.AxonServerEventStoreClient     : Done request for 2b158c88-b810-4643-9db4-4096edea5621: 22ms, 5 events
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.LockingRepository$$Lambda$1300/0x0000000800a0d440 for phase CLEANUP
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.AbstractRepository$$Lambda$1301/0x0000000800a0d840 for phase ROLLBACK
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.AbstractRepository$$Lambda$1302/0x0000000800a0dc40 for phase PREPARE_COMMIT
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : handling WithdrawMoneyCommand(accountID=2b158c88-b810-4643-9db4-4096edea5621, holderID=76147ef5-280f-439e-b017-bcd04028f176, amount=10)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=76147ef5-280f-439e-b017-bcd04028f176, accountID=2b158c88-b810-4643-9db4-4096edea5621, amount=10)
[nio-8080-exec-3] c.c.command.aggregate.AccountAggregate   : balance 260
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1222/0x00000008008f3440 for phase AFTER_COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1223/0x00000008008f3840 for phase ROLLBACK
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1225/0x00000008008f4040 for phase PREPARE_COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1226/0x00000008008f4440 for phase COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1227/0x00000008008f4840 for phase AFTER_COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1228/0x00000008008f4c40 for phase CLEANUP
[nio-8080-exec-3] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[nio-8080-exec-3] o.a.m.unitofwork.AbstractUnitOfWork      : Committing Unit Of Work
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase PREPARE_COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.axonserver.connector.event.axon.AxonServerEventStore$AxonIQEventStorageEngine$$Lambda$1245/0x000000080091f040 for phase ROLLBACK
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.axonserver.connector.event.axon.AxonServerEventStore$AxonIQEventStorageEngine$$Lambda$1246/0x000000080091f440 for phase COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase AFTER_COMMIT
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase CLEANUP
[nio-8080-exec-3] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase CLOSED

관련 dto..

WithdrawMoneyCommand.java
    @TargetAggregateIdentifier
    private String accountID;

/withdraw api의 aggregateId 인 acoountId 에 대한 모든 이벤트를 다시 불러오는 듯 하다. 즉 위 로그처럼 acoountId에 대한 모든 이벤트를 롤백하고(마치 계좌가 없던 것 처럼) 다시 첨부터 하는 것을 반복한다. 즉 여기서는 계좌 생성(/account), 입금(/deposit), 출금 n번(/withdraw)이다.

 

event sourced aggregate

신박하다.. 데이터의 정합성은 보장될 것 같은데 효율성은 떨어질 것 같다.

 

snapshot

그래서 클론 코딩에서 알려준대로 스냅샷을 적용하고 새로운 마음으로 계정생성1, 입금2, 인출3, 인출4, 인출5 를 해본다.

아래는 인출5 api실행 시 로그다.

[nio-8080-exec-5] o.a.commandhandling.SimpleCommandBus     : Handling command [com.cqrs.command.commands.WithdrawMoneyCommand]
[nio-8080-exec-5] o.a.m.unitofwork.AbstractUnitOfWork      : Starting Unit Of Work
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.AbstractUnitOfWork$$Lambda$1192/0x000000080087ac40 for phase ROLLBACK
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase STARTED
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.UnitOfWork$$Lambda$1196/0x0000000800879c40 for phase COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.UnitOfWork$$Lambda$1197/0x0000000800879040 for phase ROLLBACK
[nio-8080-exec-5] o.a.a.c.event.axon.AxonServerEventStore  : Reading events for aggregate id f00088d7-c81a-432c-b010-28a88012f0eb
[ault-executor-4] o.a.a.c.e.AxonServerEventStoreClient     : Done request for f00088d7-c81a-432c-b010-28a88012f0eb: 12ms, 4 events
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : >> applying AccountCreationEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying DepositMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=400)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 400
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 390
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 380
[nio-8080-exec-5] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.LockingRepository$$Lambda$1246/0x00000008009c2c40 for phase CLEANUP
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.AbstractRepository$$Lambda$1247/0x00000008009c3040 for phase ROLLBACK
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.AbstractRepository$$Lambda$1249/0x00000008009c3840 for phase PREPARE_COMMIT
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : handling WithdrawMoneyCommand(accountID=f00088d7-c81a-432c-b010-28a88012f0eb, holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 370
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1260/0x00000008009c6440 for phase AFTER_COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1261/0x00000008009c6840 for phase ROLLBACK
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1263/0x00000008009c7040 for phase PREPARE_COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1264/0x00000008009c7440 for phase COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1265/0x00000008009c7840 for phase AFTER_COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1266/0x00000008009c7c40 for phase CLEANUP
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventsourcing.EventCountSnapshotTriggerDefinition$EventCountSnapshotTrigger$$Lambda$1245/0x00000008009c2840 for phase PREPARE_COMMIT
[nio-8080-exec-5] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[nio-8080-exec-5] o.a.m.unitofwork.AbstractUnitOfWork      : Committing Unit Of Work
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase PREPARE_COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.axonserver.connector.event.axon.AxonServerEventStore$AxonIQEventStorageEngine$$Lambda$1276/0x00000008009ce840 for phase ROLLBACK
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.axonserver.connector.event.axon.AxonServerEventStore$AxonIQEventStorageEngine$$Lambda$1277/0x00000008009cec40 for phase COMMIT
[nio-8080-exec-5] o.a.a.c.event.axon.AxonServerEventStore  : Reading events for aggregate id f00088d7-c81a-432c-b010-28a88012f0eb
[ault-executor-4] o.a.a.c.e.AxonServerEventStoreClient     : Done request for f00088d7-c81a-432c-b010-28a88012f0eb: 10ms, 4 events
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : >> applying AccountCreationEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying DepositMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=400)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 400
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 390
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 380
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-5] c.c.command.aggregate.AccountAggregate   : balance 370
[nio-8080-exec-5] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase AFTER_COMMIT
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase CLEANUP
[nio-8080-exec-5] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase CLOSED
[ault-executor-4] o.a.a.c.event.axon.AxonServerEventStore  : Snapshot created

 왜 400 -> 370 까지 로그가 두 번 찍히는지는 모르겠지만 마지막에 snapshot created.

이 후 인출6 시 로그. 확실히 400 -> 370 까지 다시 하지 않고 바로 360으로 간다.

[nio-8080-exec-7] o.a.commandhandling.SimpleCommandBus     : Handling command [com.cqrs.command.commands.WithdrawMoneyCommand]
[nio-8080-exec-7] o.a.m.unitofwork.AbstractUnitOfWork      : Starting Unit Of Work
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.AbstractUnitOfWork$$Lambda$1192/0x000000080087ac40 for phase ROLLBACK
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase STARTED
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.UnitOfWork$$Lambda$1196/0x0000000800879c40 for phase COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.messaging.unitofwork.UnitOfWork$$Lambda$1197/0x0000000800879040 for phase ROLLBACK
[nio-8080-exec-7] o.a.a.c.event.axon.AxonServerEventStore  : Reading events for aggregate id f00088d7-c81a-432c-b010-28a88012f0eb
[ault-executor-5] o.a.a.c.e.AxonServerEventStoreClient     : Done request for f00088d7-c81a-432c-b010-28a88012f0eb: 15ms, 1 events
[nio-8080-exec-7] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.LockingRepository$$Lambda$1246/0x00000008009c2c40 for phase CLEANUP
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.AbstractRepository$$Lambda$1247/0x00000008009c3040 for phase ROLLBACK
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.modelling.command.AbstractRepository$$Lambda$1249/0x00000008009c3840 for phase PREPARE_COMMIT
[nio-8080-exec-7] c.c.command.aggregate.AccountAggregate   : handling WithdrawMoneyCommand(accountID=f00088d7-c81a-432c-b010-28a88012f0eb, holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, amount=10)
[nio-8080-exec-7] c.c.command.aggregate.AccountAggregate   : applying WithdrawMoneyEvent(holderID=b232a9e8-d280-48bc-9d17-df03c9fe4071, accountID=f00088d7-c81a-432c-b010-28a88012f0eb, amount=10)
[nio-8080-exec-7] c.c.command.aggregate.AccountAggregate   : balance 360
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1260/0x00000008009c6440 for phase AFTER_COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1261/0x00000008009c6840 for phase ROLLBACK
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1263/0x00000008009c7040 for phase PREPARE_COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1264/0x00000008009c7440 for phase COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1265/0x00000008009c7840 for phase AFTER_COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.eventhandling.AbstractEventBus$$Lambda$1266/0x00000008009c7c40 for phase CLEANUP
[nio-8080-exec-7] org.axonframework.messaging.Scope        : Clearing out ThreadLocal current Scope, as no Scopes are present
[nio-8080-exec-7] o.a.m.unitofwork.AbstractUnitOfWork      : Committing Unit Of Work
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase PREPARE_COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.axonserver.connector.event.axon.AxonServerEventStore$AxonIQEventStorageEngine$$Lambda$1276/0x00000008009ce840 for phase ROLLBACK
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Adding handler org.axonframework.axonserver.connector.event.axon.AxonServerEventStore$AxonIQEventStorageEngine$$Lambda$1277/0x00000008009cec40 for phase COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase AFTER_COMMIT
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase CLEANUP
[nio-8080-exec-7] o.a.m.u.MessageProcessingContext         : Notifying handlers for phase CLOSED

그 이후로도 입금/출금 계속 했더니 위처럼 반복되다가 5번째마다 스냅샷이 잘 찍히는 것을 알 수 있다.

---

실패기록:

api를 몇 번 랜덤하게 쐈더니 아래와 같은 에러가 났다.

AxonServerException OUT_OF_RANGE: [AXONIQ-2000] Invalid sequence number while storing snapshot.

..왜 나에게만 이런 시련이

스택오버플로우에서 알려준대로 application.yml에 아래를 추가하고 재시작하니 해결되었다.. (하지만 그거시 아니었다..ㅎ)

axon:
    eventhandling:
        processors:
            name:
                mode: tracking

무슨 의미인지 찾아보던 중, 원문에 default가 tracking이라는데 저걸 또 명시하는게 무슨 의미인가 싶은데... 또 에러가 해결은 되고... ㅎ

Event Processors come in roughly two forms: Subscribing and Tracking. The Subscribing Event Processors subscribe themselves to a source of Events and are invoked by the thread managed by the publishing mechanism. Tracking Event Processors, on the other hand, pull their messages from a source using a thread that it manages itself.
...
By default, Axon will use Tracking Event Processors.

event processor 설명: https://cla9.tistory.com/15?category=814447 

11. Query 어플리케이션 구현(Event) - 1

 

아니, 해결된 줄 알고 또 몇 번 해보니 아래의 에러가 나온다. 구글링해도 뭐가 안 나온다.. 돌겠네..ㅋㅋㅋㅋ 

ConcurrencyException: OUT_OF_RANGE: [AXONIQ-2000] Invalid sequence number while storing snapshot.

 

내가 같은 holderId로 계좌 생성을 두번했는데, 서로 다른 계좌가 생성되긴 했지만,, 뭔가 그 후로 sequence 가 꼬인 듯.. 싶다.

무튼 저거 버리고 다시 처음부터 하니 그 후론 재연도 안된다 ㅎㅅㅎ;

 

궁금한게, 분명 axon server 안에서 저 이벤트/스냅샷을 저장하고 있다가 복기하는 것 같은데.. 어디에 있는지 모르겠다.

그걸 확인해서 꼬인 부분을 해결해보려고 했는데, 프로퍼티에 설정한 디비 테이블을 뒤져도 다 empty라서.. 어디에 저장하는지 궁금하다.

+ 찾아보니,

현재 구현 버전은 event-sourced-aggregate 이라하여 axon server의 event store에 저장하는 구현 방식이다. 즉 설정파일(axonserver.properties)에 지정한 경로에 파일로 각 이벤트를 저장하는 것이다. 

아래는 현재 내 axonserver의 설정과 데이터 값의 예시이다.

[root@localhost axonserver]# cat axonserver.properties 

logging.file=/var/log/axonserver/axonserver.log
logging.file.max-history=10
logging.file.max-size=10MB
axoniq.axonserver.event.storage=./events
axoniq.axonserver.snapshot.storage=./events
axoniq.axonserver.controldb-path=./data
-------------------------------------------------
[root@localhost default]# pwd
/var/lib/axonserver/events/default
[root@localhost default]# ll
-rw-r--r--. 1 axonserver axonserver 268435456  1월 18 17:11 00000000000000000000.events
-rw-r--r--. 1 axonserver axonserver 268435456  1월 18 17:11 00000000000000000000.snapshots

/// event 파일 예시

$a1fe8538-2955-4311-b371-b55811b5d1a1^R$f00088d7-c81a-432c-b010-28a88012f0eb^X^N"^PAccountAggregate(å<84><9d>áæ/2÷^A
"com.cqrs.events.WithdrawMoneyEvent^ZÐ^A<com.cqrs.events.WithdrawMoneyEvent><holderID>b232a9e8-d280-48bc-9d17-df03c9fe4071</holderID><accountID>f00088d7-c81a-432c-b010-28a88012f0eb</accountID><amount>10</amount></com.cqrs.events.WithdrawMoneyEvent>rW<96>^]^@^@^Ae^B^@^A^@^@^Aa

/// snapshot 파일 예시

$67179188-1d02-4a6a-ade3-49cd5586b88c^R$f00088d7-c81a-432c-b010-28a88012f0eb^X^H"^PAccountAggregate(<93>ñ<87>àæ/2<95>^B
+com.cqrs.command.aggregate.AccountAggregate^Zå^A<com.cqrs.command.aggregate.AccountAggregate><accountID>f00088d7-c81a-432c-b010-28a88012f0eb</accountID><holderID>b232a9e8-d280-48bc-9d17-df03c9fe4071</holderID><balance>740</balance></com.cqrs.command.aggregate.AccountAggregate>±C>Ò^@^@^A<84>^B^@^A^@^@^A<80>

 

위의 나의 궁금증을 해결하기 위해서는 다음 글에서 설명하는 (디비에 저장하는) state-stored-aggregate을 공부하면 될 듯 하다.

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참고자료

설명

https://docs.axoniq.io/reference-guide/v/4.0/configuring-infrastructure-components/event-processing/event-processors

Event Processors - Axon Reference Guide

boot 설정 값

https://docs.axoniq.io/reference-guide/v/3.3/part-iii-infrastructure-components/spring-boot-autoconfiguration

Spring Boot AutoConfiguration - Axon Reference Guide