I have a column family contains time series events, all columns have a 24 hour TTL and gc_grace_seconds is currently 20 days. There is a TimeUUID in part of the key.
It takes 15 days to repair the entire ring.
Consistency is not my main worry. Speed is. We currently write to this CF at LOCAL_QUORUM and read at ONE.
Is there any reason to have gc_grace_seconds higher than the TTL? Feels like I’m just wasting resources all over given my consistency and speed requirements.
Does anyone vary their read repair ratio throughout the day.. i.e. at peak turn off read repairs, turn to 0.7 for the grave yard shift.