The much more of the specification of the change of mysql cluster. (no replies)

I am always indebted.

Mysql cluster is constructed with the following compositions now.
The total and mysqld(API) × 4 and ndb_mgmd(MGM) × 2 and ndbd(NDB) × It constructs it with two.

The first machine
･ndbd(NDB) × 1
･ndb_mgmd(MGM) × 1
･mysqld(API) × 1

The second machine
･ndbd(NDB) × 1
･ndb_mgmd(MGM) × 1
･mysqld(API) × 1

The third machine
･mysqld(API) × 1

The fourth machine
･mysqld(API) × 1

Please let me question on the following by the above-mentioned composition.

･When you reactivate the server whose ndbd(NDB) is master
Mysqld(API), ndb_mgmd(MGM) of all servers that unite the cluster configuration, and ndbd(NDB) determine it for about one minute. all

Will the above-mentioned phenomenon be a specification of mysql?Moreover, is it possible though it wants to reduce the number of seconds for all determination by setting the parameter at about 20 seconds?

Moreover, will the above-mentioned composition be a composition that puts mysql cluster on union and is the best?

Please continue your favors toward the degree about the professor.