"
The messaging service is (as many other services) present in
the global namespace and is widely accessed from where needed
with global get(_local)?_messaging_service() calls. There's a
long-term task to get rid of this globality and make services
and componenets reference each-other and, for and due-to this,
start and stop in specific order. This set makes this for the
messaging service.
The service is very low level and doesn't depend on anything.
It's used by gossiper, streaming, repair, migration manager,
storage proxy, storage service and API. According to this
dependencies the set consists of several parts:
patches 1-9 are preparatory, they encapsulate messaging service
init/fini stuff in its own module and decouple it from the
db::config
patch 10-12 introduce local service reference in main and set
its init/fini calls at the early stage so that this reference
can later be passed to those depending on it
patches 13-42 replace global referencing of messaging service
from other subsystems with local references initialized from
main.
patch 43 finalizes tests.
patch 44 wraps things up with removing global messaiging service
instance along with get(_local)?_messaging_service calls.
The service's stopping part is deliberately left incomplete (as
it is now), the sharded service remains alive, only the instance's
stop() method is called (and is empty for a while). Since the
messaging service's users still do not stop cleanly, its instances
should better continue leaking on exit.
Once (if) the seastar gets the helper rpc::has_handlers() method
merged the messaging_service::stop() will be able to check if all
the verbs had been unregistered (spoiler: not yet, more fixes to
come).
For debugging purposes the pointer on now-local messaging service
instance is kept in service::debug namespace.
tests: unit(dev)
dtest(dev: simple_boot_shutdown, repair, update_cluster_layout)
manual start-stop
"
* 'br-unglobal-messaging-service-2' of https://github.com/xemul/scylla: (44 commits)
messaging_service: Unglobal messaging service instance
tests: Use own instances of messaging_service
storage_service: Use local messaging reference
storage_service: Keep reference on sharded messaging service
migration_manager: Add messaging service as argument to get_schema_definition
migration_manager: Use local messaging reference in simple cases
migration_manager: Keep reference on messaging
migration_manager: Make push_schema_mutation private non-static method
migration_manager: Move get_schema_version verb handling from proxy
repair: Stop using global messaging_service references
repair: Keep sharded messaging service reference on repair_meta
repair: Keep sharded messaging service reference on repair_info
repair: Keep reference on messaging in row-level code
repair: Keep sharded messaging service in API
repair: Unset API endpoints on stop
repair: Setup API endpoints in separate helper
repair: Push the sharded<messaging_service> reference down to sync_data_using_repair
repair: Use existing sharded db reference
repair: Mark repair.cc local functions as static
streaming: Keep messaging service on send_info
...