SET @save_slave_domain_parallel_threads= @@GLOBAL.slave_domain_parallel_threads;
SELECT @@GLOBAL.slave_domain_parallel_threads as 'must be zero because of default';
must be zero because of default
0
SELECT @@SESSION.slave_domain_parallel_threads  as 'no session var';
ERROR HY000: Variable 'slave_domain_parallel_threads' is a GLOBAL variable
SET GLOBAL slave_domain_parallel_threads= 0;
SET GLOBAL slave_domain_parallel_threads= DEFAULT;
SET GLOBAL slave_domain_parallel_threads= 10;
SELECT @@GLOBAL.slave_domain_parallel_threads;
@@GLOBAL.slave_domain_parallel_threads
10
SET GLOBAL slave_domain_parallel_threads = @save_slave_domain_parallel_threads;