62e27e0f77
The test starts a 3-node cluster and immediately creates a big file
on the first nodes in order to trigger the out of space prevention to
disable compaction, including the SPLIT compaction.
In order to trigger a SPLIT compaction, a keyspace with 1 initial tablet
is created followed by alter statement with `tablets = {'min_tablet_count': 2}`.
This triggers a resize decision that should not finalize due to
disabled compaction on the first node.
The test is flaky because, the keyspace is created with RF=1 and there
is no guarantee that the tablet replica will be located on the first node
with critical disk utilization. If that is not the case, the split
is finalized and the test fails, because it expect the split to be
blocked.
Change to RF=3. This ensures there is exactly one tablet replica on
each node, including the one with critical disk utilization. So SPLIT
is blocked until the disk utilization on the first node, drops below
the critical level.
Fixes: https://github.com/scylladb/scylladb/issues/25861
Closes scylladb/scylladb#26225
Extension of the cluster tests, where all tests require externally mounted volumes to be used by scylla cluster nodes. The volumes are passed with --workdir.
The volumes can be of any size. A help generator space_limited_servers is provided
to easily create a cluster of any given number of nodes, where each node operates in
a separate volume.