We make the `consistent-topology-changes` experimental feature
unused and assumed to be true in 6.0. We remove code branches that
executed if `consistent-topology-changes` was disabled.
The `force_gossip_based_join` error injection does exactly what we
expect from `force-gossip-topology-changes` so we can do a simple
replacement.
We prefer a flag over an error injection because we will use it
a lot in CI jobs' configurations, some tests, manual testing etc.
It's much more convenient.
Moreover, the flag can be used in the release mode, so we re-enable
all tests that were disabled in release mode only because of using
the `force_gossip_based_join` error injection.
The name of the `force-gossip-topology-changes` flag suggests that
using it should always succesfully force the gossip-based topology
or, if forcing is not possible, the booting should fail. We don't
want a node with `force-gossip-topology-changes=true` that silently
boots in the raft-topology mode. We achieve it by throwing a
runtime error from `join_cluster` in two cases:
- the node is restarting in the cluster that is using raft topology
- the node is joining the cluster that is using raft topology
With auth-v2 we can login even if quorum is lost. So test
which checks if error occurs in such situation is deleted
and the opposite test which checks if logging in works was
added.
This commit adds the auth_cluster test suite to test a custom scenario
involving password authentication:
- create a cluster of 2 nodes with password authentication
- down one node
- the other node should refuse login stating that it couldn't reach
QUORUM
References ScyllaDB OSS #2339
