What I am curious about is these 2 lines:
full sync: 0/64 shards
full sync: 0/128 shards
Is this considered normal? If so, why have those lines present in this output?
This appears to be normal. My interpretation is those numbers show how many shards are
currently syncing, so it would be intentional that the full sync numbers slowly go down to
0 as the full sync progresses through the shards and the incremental sync numbers stay up
since the incremental sync is continuously running for all shards.