These settings are available in system.settings and are autogenerated from source.
parts_to_delay_insert
Type
UInt64
Default
0
If the destination table contains at least that many active parts in a single partition, artificially slow down insert into table.
parts_to_throw_insert
Type
UInt64
Default
0
If more than this number active parts in a single partition of the destination table, throw ‘Too many parts …’ exception.