Using Read and Write Consistency Level of Quorum - how many nodes can be down?

ScyllaDB
1

I have a 5 nodes cluster and use a Replication Factor of 3.
I’m using the Read and Write Consistency Level of Quorum.
How many nodes can be down before Writes or Reads requests start to fail?

2

You can check that as well as other scenarios specific to your use case using the Consistency Level Calculator.

If you want a better understanding of Availability and what happens in different scenarios the High Availability lesson on ScyllaDB University is a good place to start.