ZooKeeper session expired in tests

Question

I'm using the EmbeddedKafka for testing my module with the following annotation confiugration:

@ExtendWith(SpringExtension.class)
@SpringBootTest
@TestPropertySource(locations = "classpath:test.properties")
@EmbeddedKafka(partitions = 1,
    topics = {"topic"},
    brokerProperties = {
        "auto.create.topics.enable=${topics.autoCreate:false}",
        "delete.topic.enable=${topic.delete:true}",
        "broker.id=2"})

It works most of the times.

But sometimes, it fails in the creation of the spring context because zookeeper session times out:

java.lang.IllegalStateException: Failed to load ApplicationContext at

...

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embeddedKafka': Invocation of init method failed; nested exception is org.apache.zookeeper.KeeperException$SessionExpiredException: KeeperErrorCode = Session expired at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1745) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:410) at org.springframework.kafka.test.context.EmbeddedKafkaContextCustomizer.customizeContext(EmbeddedKafkaContextCustomizer.java:106) at org.springframework.boot.test.context.SpringBootContextLoader$ContextCustomizerAdapter.initialize(SpringBootContextLoader.java:320) at org.springframework.boot.SpringApplication.applyInitializers(SpringApplication.java:649) at org.springframework.boot.SpringApplication.prepareContext(SpringApplication.java:373) at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:127) at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99) at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117) ... 73 more Caused by: org.apache.zookeeper.KeeperException$SessionExpiredException: KeeperErrorCode = Session expired at org.apache.zookeeper.KeeperException.create(KeeperException.java:130) at kafka.zk.KafkaZkClient.checkedEphemeralCreate(KafkaZkClient.scala:1631) at kafka.zk.KafkaZkClient.registerBroker(KafkaZkClient.scala:87) at kafka.server.KafkaServer.startup(KafkaServer.scala:257) at kafka.utils.TestUtils$.createServer(TestUtils.scala:132) at kafka.utils.TestUtils.createServer(TestUtils.scala) at org.springframework.kafka.test.EmbeddedKafkaBroker.afterPropertiesSet(EmbeddedKafkaBroker.java:215) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1804) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1741) ... 82 more

Does someone know why would it happen? Why does it even need ZooKeeper when using an EmbeddedKafka??

Any help would be appreciated.