在redis集群中，若主节点出现故障，如何让子节点成为主节点？

刚查了一下，在redis.conf文件中，有这样一段话：
# The slave priority is an integer number published by Redis in the INFO output.
# It is used by Redis Sentinel in order to select a slave to promote into a
# master if the master is no longer working correctly.
#
# A slave with a low priority number is considered better for promotion, so
# for instance if there are three slaves with priority 10, 100, 25 Sentinel will
# pick the one wtih priority 10, that is the lowest.
#
# However a special priority of 0 marks the slave as not able to perform the
# role of master, so a slave with priority of 0 will never be selected by
# Redis Sentinel for promotion.
#
# By default the priority is 100.
slave-priority 100
大致意思就是通过设置从节点的优先级，来决定从节点是否能扮演主节点的角色。优先级是0的将不会成为主节点