Mongo transation exception when using the latest Spring Data Mongo reactive - spring-data-mongodb

Question

When I tried the transaction feature with Mongo 4 and the latest Spring Data Mongo Reactive, I got the failure like this.
18:57:22.823 [main] ERROR org.mongodb.driver.client - Callback onResult call produced an error
reactor.core.Exceptions$ErrorCallbackNotImplemented: com.mongodb.MongoClientException: Sessions are not supported by the MongoDB cluster to which this client is connected
Caused by: com.mongodb.MongoClientException: Sessions are not supported by the MongoDB cluster to which this client is connected
at com.mongodb.async.client.MongoClientImpl$1.onResult(MongoClientImpl.java:90)
at com.mongodb.async.client.MongoClientImpl$1.onResult(MongoClientImpl.java:83)
at com.mongodb.async.client.ClientSessionHelper$2.onResult(ClientSessionHelper.java:80)
at com.mongodb.async.client.ClientSessionHelper$2.onResult(ClientSessionHelper.java:73)
at com.mongodb.internal.connection.BaseCluster$ServerSelectionRequest.onResult(BaseCluster.java:433)
at com.mongodb.internal.connection.BaseCluster.handleServerSelectionRequest(BaseCluster.java:297)
at com.mongodb.internal.connection.BaseCluster.selectServerAsync(BaseCluster.java:157)
at com.mongodb.internal.connection.SingleServerCluster.selectServerAsync(SingleServerCluster.java:41)
at com.mongodb.async.client.ClientSessionHelper.createClientSession(ClientSessionHelper.java:68)
at com.mongodb.async.client.MongoClientImpl.startSession(MongoClientImpl.java:83)
at com.mongodb.reactivestreams.client.internal.MongoClientImpl$1.apply(MongoClientImpl.java:153)
at com.mongodb.reactivestreams.client.internal.MongoClientImpl$1.apply(MongoClientImpl.java:150)
at com.mongodb.async.client.SingleResultCallbackSubscription.requestInitialData(SingleResultCallbackSubscription.java:38)
at com.mongodb.async.client.AbstractSubscription.tryRequestInitialData(AbstractSubscription.java:153)
at com.mongodb.async.client.AbstractSubscription.request(AbstractSubscription.java:84)
at com.mongodb.reactivestreams.client.internal.ObservableToPublisher$1$1.request(ObservableToPublisher.java:50)
at reactor.core.publisher.MonoNext$NextSubscriber.request(MonoNext.java:102)
at reactor.core.publisher.MonoProcessor.onSubscribe(MonoProcessor.java:399)
at reactor.core.publisher.MonoNext$NextSubscriber.onSubscribe(MonoNext.java:64)
at com.mongodb.reactivestreams.client.internal.ObservableToPublisher$1.onSubscribe(ObservableToPublisher.java:39)
at com.mongodb.async.client.SingleResultCallbackSubscription.<init>(SingleResultCallbackSubscription.java:33)
at com.mongodb.async.client.Observables$2.subscribe(Observables.java:76)
at com.mongodb.reactivestreams.client.internal.ObservableToPublisher.subscribe(ObservableToPublisher.java:36)
at reactor.core.publisher.MonoFromPublisher.subscribe(MonoFromPublisher.java:43)
at reactor.core.publisher.Mono.subscribe(Mono.java:3555)
at reactor.core.publisher.MonoProcessor.add(MonoProcessor.java:531)
at reactor.core.publisher.MonoProcessor.subscribe(MonoProcessor.java:444)
at reactor.core.publisher.MonoFlatMapMany.subscribe(MonoFlatMapMany.java:49)
at reactor.core.publisher.Flux.subscribe(Flux.java:7677)
at reactor.core.publisher.Flux.subscribeWith(Flux.java:7841)
at reactor.core.publisher.Flux.subscribe(Flux.java:7670)
at reactor.core.publisher.Flux.subscribe(Flux.java:7634)
at com.example.demo.DataInitializer.init(DataInitializer.java:42)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.context.event.ApplicationListenerMethodAdapter.doInvoke(ApplicationListenerMethodAdapter.java:261)
at org.springframework.context.event.ApplicationListenerMethodAdapter.processEvent(ApplicationListenerMethodAdapter.java:180)
at org.springframework.context.event.ApplicationListenerMethodAdapter.onApplicationEvent(ApplicationListenerMethodAdapter.java:142)
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:398)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:355)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:884)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551)
at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:88)
at com.example.demo.Application.main(Application.java:24)
I used a initialization class to initialize this class.
#Component
#Slf4j
class DataInitializer {
private final ReactiveMongoOperations mongoTemplate;
public DataInitializer(ReactiveMongoOperations mongoTemplate) {
this.mongoTemplate = mongoTemplate;
}
#EventListener(value = ContextRefreshedEvent.class)
public void init() {
log.info("start data initialization ...");
this.mongoTemplate.inTransaction()
.execute(
s ->
Flux
.just("Post one", "Post two")
.flatMap(
title -> s.insert(Post.builder().title(title).content("content of " + title).build())
)
)
.subscribe(
null,
null,
() -> log.info("done data initialization...")
);
}
}
The subscribe caused this exception.
The source code is pushed to my github.
I just replace the content of DataInitializer with the new mongoTemplate.inTransaction().
PS: I used the latest Mongo in a Docker container to serve the mongodb service, at the moment, it was 4.0.1. The Docker console shows:
mongodb_1 | 2018-08-20T15:56:04.434+0000 I CONTROL [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'
mongodb_1 | 2018-08-20T15:56:04.447+0000 I CONTROL [initandlisten] MongoDB starting : pid=1 port=27017 dbpath=/data/db 64-bit host=12635c1c3d2d
mongodb_1 | 2018-08-20T15:56:04.447+0000 I CONTROL [initandlisten] db version v4.0.1
mongodb_1 | 2018-08-20T15:56:04.448+0000 I CONTROL [initandlisten] git version: 54f1582fc6eb01de4d4c42f26fc133e623f065fb
UPDATE: When I tried to start up Mongo servers as Replica Set via a Docker Compose file:
version: "3"
services:
mongo1:
hostname: mongo1
container_name: localmongo1
image: mongo:4.0-xenial
ports:
- "27017:27017"
restart: always
entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
mongo2:
hostname: mongo2
container_name: localmongo2
image: mongo:4.0-xenial
ports:
- "27018:27017"
restart: always
entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
mongo3:
hostname: mongo3
container_name: localmongo3
image: mongo:4.0-xenial
ports:
- "27019:27017"
restart: always
entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
And change the Mongo uri string to:
mongodb://localhost:27017,localhost:27018,localhost:27019/blog
Then got the failure info like:
11:08:20.845 [main] INFO org.mongodb.driver.cluster - No server chosen by com.mongodb.async.client.ClientSessionHelper$1#796d3c9f from cluster description ClusterDescription{type=UNKNOWN,