Commit 876478b84f ("storage_service: allow concurrent tablet migration in tablets/move API", 2024-02-08) introduced a code path on which the topology state machine would be busy -- in "tablet_draining" or "tablet_migration" state -- at the time of starting tablet migration. The pre-commit code would unconditionally transition the topology to "tablet_migration" state, assuming the topology had been idle previously. On the new code path, this state change would be idempotent if the topology state machine had been busy in "tablet_migration", but the state change would incorrectly overwrite the "tablet_draining" state otherwise.
Restrict the state change to when the topology state machine is idle.
In addition, add the topology update to the "updates" vector with plain push_back(). emplace_back() is not helpful here, as topology_mutation_builder::build() cannot construct in-place, and so we invoke the "canonical_mutation" move constructor once, either way.
Unit test:
Start a two node cluster. Create a single tablet on one of the nodes. Start decommissioning that node, but block decommissioning at once. In that state (i.e., in "tablet_draining"), move the tablet manually to the other node. Check that transit_tablet() leaves the topology transition state alone.
Fixes https://github.com/scylladb/scylladb/issues/20073.
Commit 876478b84f was first released in scylla-6.0.0, so we might want to backport this patch accordingly.
Closesscylladb/scylladb#23751
* github.com:scylladb/scylladb:
storage_service: add unit test for mid-decommission transit_tablet()
storage_service: preserve state of busy topology when transiting tablet
Start a two node cluster. Create a single tablet on one of the nodes.
Start decommissioning that node, but block decommissioning at once. In
that state (i.e., in "tablet_draining"), move the tablet manually to the
other node. Check that transit_tablet() leaves the topology transition
state alone.
Signed-off-by: Laszlo Ersek <laszlo.ersek@scylladb.com>
We move the test `test_alter_tablet_keyspace_rf` from the cqlpy to the
cluster test suite. The reason behind the change is that the test cannot
be run with `rf_rack_valid_keyspaces` turned on in the configuration.
During the test, we make the keyspace RF-rack-invalid multiple times.
Since RF-rack-validity is a very strong constraint, adjust the test
otherwise is impossible.
By moving it to the cluster test suite, we're able to change the
configuration of the node used in the test, and so the test can work
again.
Some of the statements in the test are not indented properly
and, as a result, are never run. It's most likely a small mistake,
so let's fix it.
Closesscylladb/scylladb#23659
This series add a new config option: `tablets_mode_for_new_keyspaces` that replaces the existing
`enable_tablets` option. It can be set to the following values:
disabled: New keyspaces use vnodes by default, unless enabled by the tablets={'enabled':true} option
enabled: New keyspaces use tablets by default, unless disabled by the tablets={'disabled':true} option
enforced: New keyspaces must use tablets. Tablets cannot be disabled using the CREATE KEYSPACE option
`tablets_mode_for_new_keyspaces=disabled` or `tablets_mode_for_new_keyspaces=enabled` control whether
tablets are disabled or enabled by default for new keyspaces, respectively.
In either cases, tablets can be opted-in or out using the `tablets={'enabled':...}`
keyspace option, when the keyspace is created.
`tablets_mode_for_new_keyspaces=enforced` enables tablets by default for new keyspaces,
like `tablets_mode_for_new_keyspaces=enabled`.
However, it does not allow to opt-out when creating
new keyspaces by setting `tablets = {'enabled': false}`
Refs scylladb/scylla-enterprise#4355
* Requires backport to 2025.1
Closesscylladb/scylladb#22273
* github.com:scylladb/scylladb:
boost/tablets_test: verify failure to create keyspace with tablets and non network replication strategy
tablets: enforce tablets using tablets_mode_for_new_keyspaces=enforced config option
db/config: add tablets_mode_for_new_keyspaces option
Resize finalization is executed in a separate topology transition state,
`tablet_resize_finalization`, to ensure it does not overlap with tablet
transitions. The topology transitions into the
`tablet_resize_finalization` state only when no tablet migrations are
scheduled or being executed. If there is a large load-balancing backlog,
split finalization might be delayed indefinitely, leaving the tables
with large tablets.
To fix this, do not schedule tablet migrations on any tables when there
are pending resize finalizations. This ensures that migrations from the
same table and other unrelated tables do not block resize finalization.
Also added a testcase to verify the fix.
Fixes#21762
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
The new option deprecates the existing `enable_tablets` option.
It will be extended in the next patch with a 3rd value: "enforced"
while will enable tablets by default for new keyspace but
without the posibility to opt out using the `tablets = {'enabled':
false}` keyspace schema option.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
