Our Discourse uses Redis cluster created in Amazon Elasticache which allows enabling in-transit encryption (TLS). However, once we enable TLS on Elasticache Discourse fails to connect to the Redis.
Looks like Discourse doesn’t support this, although redis-rb client does as mentioned in the similar issue here Redis::ConnectionError: Connection lost (ECONNRESET) when using ElastiCache with TLS enabled · Issue #771 · redis/redis-rb · GitHub
I’m adding pr-welcome on that. Feel free to submit one @Yevhenii_Baraniuk 
Update: I started implementing this feature but faced the problem that hiredis driver which Discourse uses doesn’t support SSL at the moment (as for Jul 2019), though redis-rb client does. I’ll come back to the PR once the new version of hiredis is released which is going to support SSL 
hiredis는 이미 오래전에 @sam 덕분에 사라졌기 때문에, 저는 Redis 연결에 TLS 기능을 추가하는 PR을 만들었습니다:
지금 테스트 중이며 정상적으로 작동합니다.