After having a high load, the redis connections get closed automatically and error "Subscription has been unsubscribed and cannot be used anymore" is thrown.
We use the pub/sub event.
Bypass: if we uncomment the line

redisMessageListenerContainer.addMessageListener(listenerAdapter, new PatternTopic("Dummy"));

then it keeps working.
We have 3 Redis Machines in a cluster. See the attached example code and some logging in the target folder.