Spring Session Redis - always getting could not get resource from pool - (but no error in Docker...)

Describe the bug
This is the bug I keep getting, when I load my Spring Application:

2024-08-23T00:17:20.005+01:00  INFO 9758 --- [BFFApplication] [           main] o.s.b.web.embedded.netty.NettyWebServer  : Netty started on port 9090 (http)
2024-08-23T00:17:20.042+01:00  INFO 9758 --- [BFFApplication] [           main] com.example.bff.BFFApplicationKt         : Started BFFApplicationKt in 7.754 seconds (process running for 8.275)
2024-08-23T00:17:20.071+01:00  INFO 9758 --- [BFFApplication] [ioEventLoop-5-1] c.example.bff.auth.redis.SessionEvicter  : No sessions found to remove.
2024-08-23T00:17:20.071+01:00  INFO 9758 --- [BFFApplication] [ioEventLoop-5-1] c.example.bff.auth.redis.SessionEvicter  : Cleanup operation completed.
2024-08-23T00:17:25.823+01:00  WARN 9758 --- [BFFApplication] [oundedElastic-1] o.s.b.a.d.r.RedisReactiveHealthIndicator : Redis health check failed

org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.translateException(LettuceConnectionFactory.java:1847) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1778) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1580) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.lambda$getConnection$0(LettuceConnectionFactory.java:1560) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.doInLock(LettuceConnectionFactory.java:1521) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getConnection(LettuceConnectionFactory.java:1557) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getSharedReactiveConnection(LettuceConnectionFactory.java:1268) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getReactiveConnection(LettuceConnectionFactory.java:1143) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getReactiveConnection(LettuceConnectionFactory.java:119) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at reactor.core.publisher.MonoSupplier.call(MonoSupplier.java:67) ~[reactor-core-3.6.8.jar:3.6.8]
	at reactor.core.publisher.FluxSubscribeOnCallable$CallableSubscribeOnSubscription.run(FluxSubscribeOnCallable.java:228) ~[reactor-core-3.6.8.jar:3.6.8]
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:68) ~[reactor-core-3.6.8.jar:3.6.8]
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:28) ~[reactor-core-3.6.8.jar:3.6.8]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317) ~[na:na]
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[na:na]
	at java.base/java.lang.Thread.run(Thread.java:1623) ~[na:na]
Caused by: org.springframework.data.redis.connection.PoolException: Could not get a resource from the pool
	at org.springframework.data.redis.connection.lettuce.LettucePoolingConnectionProvider.getConnection(LettucePoolingConnectionProvider.java:104) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1776) ~[spring-data-redis-3.3.2.jar:3.3.2]
	... 16 common frames omitted
Caused by: io.lettuce.core.RedisConnectionException: Unable to connect to abc.redis.cache.windows.net/<unresolved>:6380
	at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:78) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:56) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at io.lettuce.core.AbstractRedisClient.getConnection(AbstractRedisClient.java:350) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at io.lettuce.core.RedisClient.connect(RedisClient.java:215) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.lambda$getConnection$1(StandaloneConnectionProvider.java:112) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at java.base/java.util.Optional.orElseGet(Optional.java:364) ~[na:na]
	at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.getConnection(StandaloneConnectionProvider.java:112) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at org.springframework.data.redis.connection.lettuce.LettucePoolingConnectionProvider.lambda$getConnection$0(LettucePoolingConnectionProvider.java:93) ~[spring-data-redis-3.3.2.jar:3.3.2]
	at io.lettuce.core.support.ConnectionPoolSupport$RedisPooledObjectFactory.create(ConnectionPoolSupport.java:211) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at io.lettuce.core.support.ConnectionPoolSupport$RedisPooledObjectFactory.create(ConnectionPoolSupport.java:201) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at org.apache.commons.pool2.BasePooledObjectFactory.makeObject(BasePooledObjectFactory.java:70) ~[commons-pool2-2.11.1.jar:2.11.1]
	at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:571) ~[commons-pool2-2.11.1.jar:2.11.1]
	at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:298) ~[commons-pool2-2.11.1.jar:2.11.1]
	at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:223) ~[commons-pool2-2.11.1.jar:2.11.1]
	at io.lettuce.core.support.ConnectionPoolSupport$1.borrowObject(ConnectionPoolSupport.java:122) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at io.lettuce.core.support.ConnectionPoolSupport$1.borrowObject(ConnectionPoolSupport.java:117) ~[lettuce-core-6.3.2.RELEASE.jar:6.3.2.RELEASE/8941aea]
	at org.springframework.data.redis.connection.lettuce.LettucePoolingConnectionProvider.getConnection(LettucePoolingConnectionProvider.java:99) ~[spring-data-redis-3.3.2.jar:3.3.2]
	... 17 common frames omitted
Caused by: java.net.SocketException: Connection reset
	at java.base/sun.nio.ch.SocketChannelImpl.throwConnectionReset(SocketChannelImpl.java:401) ~[na:na]
	at java.base/sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:434) ~[na:na]
	at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:255) ~[netty-buffer-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1132) ~[netty-buffer-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:356) ~[netty-transport-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:151) ~[netty-transport-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788) ~[netty-transport-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724) ~[netty-transport-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650) ~[netty-transport-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:994) ~[netty-common-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.111.Final.jar:4.1.111.Final]
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.111.Final.jar:4.1.111.Final]
	... 1 common frames omitted

2024-08-23T00:19:20.054+01:00  INFO 9758 --- [BFFApplication] [ioEventLoop-5-1] c.example.bff.auth.redis.SessionEvicter  : No sessions found to remove.
2024-08-23T00:19:20.062+01:00  INFO 9758 --- [BFFApplication] [ioEventLoop-5-1] c.example.bff.auth.redis.SessionEvicter  : Cleanup operation completed.

Lettuce Connection Factory

I don't really understand what I'm doing wrong here:

@Configuration
internal class RedisConnectionFactoryConfig(
    private val springDataProperties: SpringDataProperties
) {

    // customize thread pool size
    private val clientResources = DefaultClientResources.builder()
        .ioThreadPoolSize(4)
        .computationThreadPoolSize(4)
        .build()

    @Bean
    @Primary
    fun reactiveRedisConnectionFactory(): ReactiveRedisConnectionFactory {

        // configure Redis standalone configuration
        val config = RedisStandaloneConfiguration()
        config.hostName = springDataProperties.redis.host
        config.port = springDataProperties.redis.port
        config.setPassword(RedisPassword.of(springDataProperties.redis.password))

        // create socket options
        val socketOptions = SocketOptions.builder()
            .keepAlive(SocketOptions.DEFAULT_SO_KEEPALIVE)
            .tcpNoDelay(SocketOptions.DEFAULT_SO_NO_DELAY)
            // time to wait for connection to be established, before considering it as a failed connection
            .connectTimeout(Duration.ofSeconds(60))
            .build()

        // create client options

        // Create SSL options if SSL is required
        val sslOptions = SslOptions.builder()
            .jdkSslProvider()  // Or use OpenSslProvider if you prefer
            .build()

        // Create timeout options
        val timeoutOptions = TimeoutOptions.builder()
            .fixedTimeout(Duration.ofSeconds(10))
            .timeoutCommands(true)
            .build()

        val clientOptions = ClientOptions.builder()
            .autoReconnect(true)
            .timeoutOptions(timeoutOptions)
            .sslOptions(sslOptions)
            .suspendReconnectOnProtocolFailure(true)
            .decodeBufferPolicy(DecodeBufferPolicies.ratio(0.5F))
            .requestQueueSize(1000)
            .disconnectedBehavior(ClientOptions.DisconnectedBehavior.REJECT_COMMANDS)
            .pingBeforeActivateConnection(true)
            .socketOptions(socketOptions)
            .build()

        // create Lettuce client configuration with authentication details
        val clientConfig = LettucePoolingClientConfiguration.builder()
            // maximum time allowed for a Redis command to execute before the operation is considered timed out.
            .commandTimeout(Duration.ofSeconds(60))
            .clientResources(clientResources)
            .clientOptions(clientOptions)
            .poolConfig(buildLettucePoolConfig())
            .useSsl()
            .build()

        // create Lettuce connection factory
        return LettuceConnectionFactory(config, clientConfig).apply {
            afterPropertiesSet()
            validateConnection = false
            setShareNativeConnection(true)
        }
    }

    // configure connection pool settings
    protected fun buildLettucePoolConfig(): GenericObjectPoolConfig<Any> {
        val poolConfig = GenericObjectPoolConfig<Any>()
        poolConfig.maxTotal = 100
        poolConfig.maxIdle = 50
        poolConfig.minIdle = 10
        poolConfig.setMaxWait(Duration.ofSeconds(120))
        poolConfig.timeBetweenEvictionRuns = Duration.ofSeconds(120)
        poolConfig.minEvictableIdleTime = Duration.ofMinutes(5)
        poolConfig.testOnBorrow = true
        poolConfig.testWhileIdle = true
        poolConfig.testOnReturn = true
        poolConfig.blockWhenExhausted = true
        poolConfig.lifo = true
        return poolConfig
    }

    @PreDestroy
    fun cleanup() {
        clientResources.shutdown()
    }

}

This always happens when I load Spring Boot. Can someone help?

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