Rails + Redis + Sidekiq error: IO::EAGAINWaitReadable

I'm getting random IO::EAGAINWaitReadable sometimes when executing a job from Sidekiq with redis as caching service.

redis and sidekiq are running on the same server. I'm also getting this issue sometimes when I try to get a value from Rails.cache.

Any idea ?

PS: No need to provide code here as it makes no sense.