Automatically adjust and/or notify about too small InnoDB buffer pool

MySQL has a certain amount of InnoDB data. For the best performance as well as lower I/O, the InnoDB buffer pool should be the same size, or larger.

Currently, the InnoDB buffer pool size is adjusted when a customer reports slowness. Instead, it could be adjusted automatically based on the amount of InnoDB data.

Note: as the InnoDB buffer pool uses RAM, and nodes have a fixed amount of RAM, we should not adjust but notify when there is not enough RAM for the intended InnoDB buffer pool size. This is a difficult calculation, as it also depends on the amount of RAM other services on a given node require.