Currently we have two live-updateable IO-throughput options -- one for
streaming and one for compaction. Both are observed and the changed
value is applied to the corresponding scheduling_group by the relevant
serice -- respectively, stream_manager and compaction_manager.
Both observe/react/apply places use pretty heavy boilerplate code for
such simple task. Next patches will make things worse by adding two more
options to control IO throughput of some other groups.
Said that, the proposal is to hold the updating code in main.cc with the
help of a wrapper class. In there all the needed bits are at hand, and
classes can get their IO updates applied easily.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
15c41bfb6c