You can change the CPU or memory (instance class) of a DB instance as required. If the status of a DB instance changes from Changing instance class to Available, the change is successful.
Choose either of the following scheduled time:
Changing the instance class takes 5–15 minutes. During this period, the status of the DB instance on the Instance Management page is Changing instance class. After a few minutes, click the instance and view the instance class on the displayed Basic Information page to check that the change is successful.
After the DB instance class is changed, the system will change the values of the following parameters accordingly: innodb_buffer_pool_size, innodb_log_buffer_size, max_connections, innodb_buffer_pool_instances, innodb_page_cleaners, innodb_parallel_read_threads, innodb_read_io_threads, innodb_write_io_threads, threadpool_size and query_cache_size.