With big number of shards in the cluster (e.g. 500+) due to cache
periodic refresh we experience high load on role_permissions table
(e.g. 1k op/s). The load on roles table is amplified because to populate
single entry in the cache we do several selects on roles table. Some
of this can't be avoided because roles are arranged in a tree-like
structure where permissions can be inherited.
This patch tries to reuse queries which are simply duplicated. It should
reduce the load on roles table by up to 50%.
Fixesscylladb/scylladb#19299Closesscylladb/scylladb#19300
* github.com:scylladb/scylladb:
auth: reuse roles select query during cache population
auth: coroutinize service::get_uncached_permissions
auth: coroutinize service::has_superuser
7567b87e72