97b7c03709
The tablet scheduler should not emit conflicting migrations for the same tablet. This was addressed initially in scylladb/scylladb#26038 but the check is missing in the merge colocation plan, so add it there as well. Without this check, the merge colocation plan could generate a conflicting migration for a tablet that is already scheduled for migration, as the test demonstrates. This can cause correctness problems, because if the load balancer generates two migrations for a single tablet, both will be written as mutations, and the resulting mutation could contain mixed cells from both migrations. Fixes scylladb/scylladb#27304 Closes scylladb/scylladb#27312
165 KiB
165 KiB