The series is on top of "wire up schema raft state machine". It will
apply without, but will not work obviously (when raft is disabled it
does nothing anyway).
This series does not provide any linearisability just yet though. It
only uses raft as a means to distribute schema mutations. To achieve
linearisability more work is needed. We need to at lease make sure
that schema mutation use monotonically increasing timestamps and,
since schema altering statement are RMW, no modification to schema
were done between schema mutation creation and application. If there
were an operation needs to be restarted.
* scylla-dev/gleb/raft-schema-v5: (59 commits)
cql3: cleanup mutation creation code in ALTER TYPE
cql3: use migration_manager::schema_read_barrier() before accessing a schema in altering statements
cql3: bounce schema altering statement to shard 0
migration_manager: add is_raft_enabled() to check if raft is enabled on a cluster
migration_manager: add schema_read_barrier() function
migration_manager: make announce() raft aware
migration_manager: co-routinize announce() function
migration_manager: pass raft_gr to the migration manager
migration_manager: drop view_ptr array from announce_column_family_update()
mm: drop unused announce_ methods
cql3: drop schema_altering_statement::announce_migration()
cql3: drop has_prepare_schema_mutations() from schema altering statement
cql3: drop announce_migration() usage from schema_altering_statement
cql3: move DROP AGGREGATE statement to prepare_schema_mutations() api
migration_manager: add prepare_aggregate_drop_announcement() function
cql3: move DROP FUNCTION statement to prepare_schema_mutations() api
migration_manager: add prepare_function_drop_announcement() function
cql3: move CREATE AGGREGATE statement to prepare_schema_mutations() api
migration_manager: add prepare_new_aggregate_announcement() function
cql3: move CREATE FUNCTION statement to prepare_schema_mutations() api
...