3 nodes vs. 4 nodes (2 replies)

Hello,

I am a little confused about the architecture of a mysql cluster. Which one is better:

- 3 nodes, 2x(data+sql), 1xmanagement
- 4 nodes, 2xdata, 2x(sql+management)

I am concerned about how to replace a data, sql or management node in case of an hardware/os failure easily and without stopping the operation.

Thank you.

Mete