Intermittent Connection refused error while connecting to Redis cluster in AWS using Redisson client - redis

Question

I am getting below error intermittently when I start the application (Kubernetes POD).
First time it starts up with 24 connections to Redis Cluster(AWS). When I restart, sometimes it gives below error.
I am using Spring Boot 2.5.5, Java 1.8 and Redisson Client library 3.17.5`
This is the way I am creating connection
Config config = new Config(); config.useSingleServer() .setAddress(<Redis URL>) .setTimeout(30 * 1000); // timeout is 30 seconds Redisson.create(config);
`Raised a case with Amazon and they did not see anything wrong with redis.
Appreciate any help.`
org.redisson.client.RedisConnectionException: Unable to connect to Redis server: <Redis URL> at org.redisson.connection.pool.ConnectionPool.lambda$createConnection$1(ConnectionPool.java:150) ~[redisson-3.17.5.jar!/:3.17.5] at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1990) ~[?:1.8.0_345] at org.redisson.connection.pool.ConnectionPool.promiseFailure(ConnectionPool.java:307) ~[redisson-3.17.5.jar!/:3.17.5] at org.redisson.connection.pool.ConnectionPool.lambda$createConnection$6(ConnectionPool.java:273) ~[redisson-3.17.5.jar!/:3.17.5] at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1990) ~[?:1.8.0_345] at org.redisson.client.RedisClient$1$2.run(RedisClient.java:235) ~[redisson-3.17.5.jar!/:3.17.5]
Caused by: java.util.concurrent.CompletionException: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: <Redis URL> at java.util.concurrent.CompletableFuture.encodeRelay(CompletableFuture.java:326) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture.completeRelay(CompletableFuture.java:338) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture.uniRelay(CompletableFuture.java:925) ~[?:1.8.0_345] at java.util.concurrent.CompletableFuture$UniRelay.tryFire(CompletableFuture.java:913) ~[?:1.8.0_345]
Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: <Redis URL> Caused by: java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) ~[?:1.8.0_345] at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:716) ~[?:1.8.0_345] at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:337)
`I tried changing the io.netty version to 4.1.79-Final. Raised a case with Amazon and they did not see anything wrong with redis.