Normal heartbeat packets carry the full configuration of a node, that can be replaced in an idempotent way with the old in order to update an old config. This means they contain the slots configuration for a node, in raw form, that uses 2k of space with16k slots, but would use a prohibitive 8k of space using 65k slots.
At the same time it is unlikely that Redis Cluster would scale to more than 1000 mater nodes because of other design tradeoffs.
So 16k was in the right range to ensure enough slots per master with a max of 1000 maters, but a small enough number to propagate the slot configuration as a raw bitmap easily. Note that in small clusters the bitmap would be hard to compress because when N is small the bitmap would have slots/N bits set that is a large percentage of bits set.

控制传输的数据包大小，提升性能；

明白了，谢谢各位专家解答

16384个槽, 这个槽是hash槽,  而hash有概率会发生hash碰撞, 所以楼主你知道了吧 其实一个hash槽里会有多个值的呢