Changes sent via sync goes way down on restart

[jeromegn]

On restart, the metric for sent changes via sync shows a marked decrease. This may only happen if restarting a few nodes.

It appears the node's sent sync only recover after it logs a "rejoined cluster" message. I'm not sure how this can happen and it should only happen when things are "wrong" in the SWIM cluster. I don't see any logs indicating that's the case though.

The node should've been announcing a new identity on start-up anyway, so I'm not sure how this rejoin works out.

Perhaps we need to tweak the config for the foca cluster.