I have 3 DB instances running on my ssg VMware, which are SSG, test, and test2DB (testDwhichch I have created). Now,I want to stop the test2DB how could I do it.
Are you referring to having multiple MYSQL DB instances on the same host or multiple DB's running on one MYSQL instance (which is the default setting for our CA API Gateway setting)?
If the later, which is most likely, you can use the MYSQL command to remove grants to that DB.
If you want to completely drop a database (that is, delete it) from the MySQL server, you can follow the MySQL documentation for that here: MySQL :: MySQL 5.5 Reference Manual :: 13.1.21 DROP DATABASE Syntax
If you do not want to drop a database from the database server, please clarify your request.