Load-and-stream is broken when running concurrently to the finalization step of tablet split.
Consider this:
1) split starts
2) split finalization executes barrier and succeed
3) load-and-stream runs now, starts writing sstable (pre-split)
4) split finalization publishes changes to tablet metadata
5) load-and-stream finishes writing sstable
6) sstable cannot be loaded since it spans two tablets
two possible fixes (maybe both):
1) load-and-stream awaits for topology to quiesce
2) perform split compaction on sstable that spans both sibling tablets
This patch implements # 1. By awaiting for topology to quiesce,
we guarantee that load-and-stream only starts when there's no
chance coordinator is handling some topology operation like
split finalization.
Fixes https://github.com/scylladb/scylladb/issues/26455.
Closesscylladb/scylladb#26456
* github.com:scylladb/scylladb:
test: Add reproducer for l-a-s and split synchronization issue
sstables_loader: Synchronize tablet split and load-and-stream
c543059f86