For replication strategies like "everywhere"
and "local" that return the same set of endpoints
for all tokens, we can call rs->calculate_natural_endpoints
one once and reuse the result for all token.
Note that ideally the replication_map could contain only
a single token range for this case, but that does't seem to work yet.
Add maybe_yield() calls to the tight loop
to prevent reactor stalls on large clusters when copying
a long vector returned by everywhere_replication_strategy
to potentially 1000's of tokens in the map.
Nicholas Peshek wrote in
https://github.com/scylladb/scylladb/issues/10337#issuecomment-1211152370
about similar patch by Geoffrey Beausire:
994c6ecf3c
> Yep. That dropped our startup from 3000+ seconds to about 40.
Fixes#10337
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
9167b857e9