On the NetApp documentation site, you will find some useful documentation such as:
Document Name : SnapCenter software Installation and setup Guide : Page 154 onwards.
However, I found one webpage while googling, which shows step by step guide to configure mysql, so please have a look and see if you have missed any key option [In your config, I see Host & Port, but Master_slave is not populated].
webpage: https://dbdevtestplugin-docs.readthedocs.io/en/latest/pre.html