Nosso Discourse utiliza um cluster Redis criado no Amazon ElastiCache, o que permite ativar a criptografia em trânsito (TLS). No entanto, assim que ativamos o TLS no ElastiCache, o Discourse deixa de conseguir conectar ao Redis.
Parece que o Discourse não oferece suporte a isso, embora o cliente redis-rb ofereça, conforme mencionado em uma questão semelhante aqui: 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 
Since hiredis is long dead thanks to @sam I created this PR which adds TLS capabilities to our Redis connections:
I’m testing it right now and it works.