This patch makes all cql connections update theirs service level parameters automatically when:
- any service level is created or changed
- one role is granted to another
- any service level is attached to/detached from a role
First of all, the patch defines what a service level and an effective service level are 938aa10509. No new type of service levels are introduced, the commit only clarifies definitions and names what an effective service level is.
(Effective service level is created by merging all service levels which are attached to all roles granted to the user. It represents exact values of connection's parameters.)
Previously, to find an effective service level of a user, it required O(n) internal queries: O(n) queries to recursively find all granted roles (`standard_role_manager::query_granted()`) and a query for each role to get its service level (`standard_role_manager::get_attribute()`, which sums to O(n) queries).
Because we want to reload SL parameters for all opened cql connections, we don't want to do O(n) queries for every connection, every time we create or change any service level/grant one role to another/attach or detach a service level to/from a role.
To speed it up, the patch adds another layer of service level controller cache, which stored `role_name -> effective_service_level` mapping. This way finding a effective service level for a role is only a lookup to a map.
Building the new cache requires only 2 queries: one to obtain all role hierarchy one to get all roles' service level.
Fixesscylladb/scylladb#12923Closesscylladb/scylladb#19085
* github.com:scylladb/scylladb:
test/auth_cluster/test_raft_service_levels: add test for automatic connection update
api/cql_server_test: add CQL server testing API
transport/cql_server: subscribe to sl effective cache reloaded
transport/controller: coroutinize `subscribe_server` and `unsubscribe_server`
transport/cql_server: add method to update service level params on all connections
generic_server: use async function in `for_each_gently()`
service/qos/sl_controller: use effective service levels cache
service/qos/service_level_controller: notify subscribers on effective cache reloaded
service/raft/group0_state_machine: update effective service levels cache
service/topology_coordinator: migrate service levels before auth
service/qos/service_level_controller: effective service levels cache
utils/sorting: allow to pass any container as verticies
service/qos/service_level_controller: replace shard check to assert
service/qos: define effective service level
service/qos/qos_common: use const reference in `init_effective_names()`
service/qos/service_level_controller: remove unused field
auth: return map of directly granted roles
test/auth/test_auth_v2_migration: create sl1 in the test
b72906518f