Many tests want to assume that group0 leader runs on a particualr
server, typically the first server in the list.
And they cannot be easily made to work with arbitrary leader, becuase
they setup a particular topology and then stop particular nodes, and
want to assume the leader is stable. They open leader's log and
expect things to appear in that log.
It's much easier to ensure the leader, than to prepare tests to
handle failovers.
Previously, `wait_until_driver_service_level_created` only waited for
the `driver` service level to appear in the output of
`LIST ALL SERVICE_LEVELS`. However, the fact that one node lists
`sl:driver` does not necessarily mean that all other nodes can see
it yet. This caused sporadic test failures, especially in DEBUG builds.
To prevent these failures, this change adds an extra wait for
a `raft/read_barrier` after the `driver` service level first appears.
This ensures the service level is globally visible across the cluster.
Fixes: scylladb/scylladb#27019
Pass a ManagerClient instead of a `cql` session to
`wait_until_driver_service_level_created`. This makes it easier
to add additional functionality to the helper later (e.g. waiting for
a Raft read barrier in a subsequent commit).
Refs: scylladb/scylladb#27019
This commit:
- Increases the number of allowed scheduling groups to allow the
creation of `sl:driver`.
- Adds the `DRIVER_SERVICE_LEVEL` feature, which prevents creating
`sl:driver` until all nodes have increased the number of
scheduling groups.
- Starts using `get_create_driver_service_level_mutations`
to unconditionally create `sl:driver` on
`raft_initialize_discovery_leader`. The purpose of this code
path is ensuring existence of `sl:driver` in new system and tests.
- Starts using `migrate_to_driver_service_level` to create `sl:driver`
if it is not already present. The creation of `sl:driver` is
managed by `topology_coordinator`, similar to other system keyspace
updates, such as the `view_builder` migration. The purpose of this
code path is handling upgrades.
- Modifies related tests to pass after `sl:driver` is added.
Later in this patch series, `sl:driver` will be used by
`transport/server` to handle selected traffic, such as the driver's
schema and topology fetches.
Refs: scylladb/scylladb#24411
This commit:
- Increases the number of allowed scheduling groups to allow the
creation of `sl:driver`.
- Adds the `DRIVER_SERVICE_LEVEL` feature, which prevents creating
`sl:driver` until all nodes have increased the number of
scheduling groups.
- Starts using `get_create_driver_service_level_mutations`
to unconditionally create `sl:driver` on
`raft_initialize_discovery_leader`. The purpose of this code
path is ensuring existence of `sl:driver` in new system and tests.
- Starts using `migrate_to_driver_service_level` to create `sl:driver`
if it is not already present. The creation of `sl:driver` is
managed by `topology_coordinator`, similar to other system keyspace
updates, such as the `view_builder` migration. The purpose of this
code path is handling upgrades.
- Modifies related tests to pass after `sl:driver` is added.
Later in this patch series, `sl:driver` will be used by
`transport/server` to handle selected traffic, such as the driver's
schema and topology fetches.
Refs: scylladb/scylladb#24411
In the Raft-based topology, a decommissioning node is removed from group
0 after the decommission request is considered finished (and the token
ring is updated). `wait_for_token_ring_and_group0_consistency` doesn't
handle such a case; it only handles cases where the token ring is
updated later. We fix this in this commit.
We rely on the new implementation of
`wait_for_token_ring_and_group0_consistency` in the following commit to
fix flakiness of some tests.
We also update the obsolete docstring in this commit.
Update the regular expression in `check_node_log_for_failed_mutations` to avoid
false test failures when DEBUG-level logging is enabled.
Fixesscylladb/scylladb#23688Closesscylladb/scylladb#23658
When we remove a node in the Raft-based topology
(by remove/replace/decommission), we remove its
tokens from `system.topology`, but we do not
change `num_tokens`. Hence, the old check could
fail for left nodes.
We extend `start_writes` to allow:
- providing `ks_name` from the test,
- restarting it (by starting it again with the same `ks_name`),
- running it in the presence of shutdowns.
We use these features in a new test in one of the following patches.
