We do not yet support enabling CDC in a keyspace that uses tablets
(Refs #16317). But the problem is that today, if this is attempted,
we get a nasty failure: the CDC code creates the extra CDC log table,
it doesn't get tablets, and Raft gets surprised and croaks with a
message like:
Raft instance is stopped, reason: "background error,
std::_Nested_exceptionraft::state_machine_error (State machine error at
raft/server.cc:1230): std::runtime_error (Tablet map not found for
table 48ca1620-9ea5-11ee-bd7c-22730ed96b85)
After Raft croaks, Scylla never recovers until it is rebooted.
In this patch, we replace this disaster by a graceful error - a CREATE
TABLE or ALTER TABLE operation with CDC enabled will fail in a clear way,
and allowing Scylla to continue operating normally after this failed request.
This fix is important for allowing us to run tests on Scylla with
tablets, and although CDC tests will fail as expected, they won't
fail the other tests that follow (Refs #16473).
Fixes#16318
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#16474
7ee55dd03e