During the investigation of scylladb/scylladb#20282, it was discovered that implementations of speculating read executors have undefined behavior when called with an incorrect number of read replicas. This PR introduces two levels of condition checking:
- Condition checking in speculating read executors for the number of replicas.
- Checking the consistency of the Effective Replication Map in filter_for_query(): the map is considered incorrect if the list of replicas contains a node from a data center whose replication factor is 0.
Please note: This PR does not fix the issue found in scylladb/scylladb#20282; it only adds condition checks to prevent undefined behavior in cases of inconsistent inputs.
Refs scylladb/scylladb#20625
As this issue applies to the releases versions and can affect clients, we need backports to 6.0, 6.1, 6.2.
Closesscylladb/scylladb#20851
* github.com:scylladb/scylladb:
Add conditions checking for get_read_executor
Avoid an extra call to block_for in db::filter_for_query.
Improve code readability in consistency_level.cc and storage_proxy.cc
tools: Add build_info header with functions providing build type information
tests: Add tests for alter table with RF=1 to RF=0
96070bb5b3