When one wants to script automated replication chain building, certain things are quite annoying, like immutable replication configuration variables. For example, at certain moments log_slave_updates is more than needed, and that's what the server says:
mysql> show variables like 'log_slave_updates'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | log_slave_updates | OFF | +-------------------+-------+ 1 row in set (0.00 sec) mysql> set global log_slave_updates=1; ERROR 1238 (HY000): Variable 'log_slave_updates' is a read only variable
