The current code:
```
try:
cql.execute(f"INSERT INTO {cf} (pk, t) VALUES (-1, 'x')", host=host[0], execution_profile=cl_one_profile).result()
except Exception:
pass
```
contains a typo: `host=host[0]` which throws an exception becase Host
object is not subscriptable. The test does not fail because the except
block is too broad and suppresses all exceptions.
Fixing the typo alone is insufficient. The write still succeeds because
the remaining nodes are UP and the query uses CL=ONE, so no failure
should be expected.
Another source of flakiness is data verification:
```
SELECT * FROM {cf} WHERE pk = 0;
```
Even when a coordinator is explicitly provided, using CL=ONE does not
guarantee a local read. The coordinator may forward the read request to
another replica, causing the verification to fail nondeterministically.
This patch rewrites the tests to address these issues:
- Fix the typo: `host[0]` to `hosts[0]`
- Verify data using `MUTATION_FRAGMENTS({cf})` which guarantees a local
read on the coordinator node
- Reconnect the driver after node restart
Fixes https://github.com/scylladb/scylladb/issues/27933
Closes scylladb/scylladb#27934
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.