2.1 counters and CL=ONE

[Robert Wille <rw...@fold3.com>]

I’m planning an upgrade from 2.0 to 2.1, and was reading about counters, and ended up with a question. I read that in 2.0, counters are implemented by storing deltas, and in 2.1, read-before-write is used to store totals instead. What does this mean for the following scenario?

Suppose we have a cluster with two nodes, RF=2 and CL=ONE. With node 2 down, a previously nonexistent counter is incremented twice. With node 1 down, the counter is incremented once. When both nodes are up, repair is run.

Does this mean that 2.0 would repair the counter by replicating the missing deltas so that both nodes have all three increments, and 2.1 would repair the counter by replicating node 2’s total to node 1? With 2.0, the count would end up 3, and with 2.1 the count would end up 1?

I assume that the implementation isn’t that naive, but I need to make sure.

Thanks

Robert