Node XXX is not empty. Either the node already knows other nodes or contains some key in database 0

关于启动redis集群或者集群（主、从）节点添加时：[ERR] Node 192.168.1.115:7007 is not empty. Either the node already knows other nodes (check with CLUSTER NODES) or contains some key in database 0.的问题

1.启动redis集群报该错误解决办法：
1)将每个节点下aof、rdb、nodes.conf本地备份文件删除；
[root@localhost 7001]# rm -rf appendonly.aof dump.rdb
……
2)192.168.1.115:7001> flushdb 清空当前数据库
3)重新连接redis集群，成功

[root@localhost redis-cluster]# vi startCluster.sh 
./redis-trib.rb create --replicas l 192.168.1.115:7001 192.168.1.115:7002 192.168.1.115:7003 192.168.1.115:7004 192.168.1.115:7005 192.168.1.115:7006
[root@localhost redis-cluster]# chmod 777 startCluster.sh 
[root@localhost redis-cluster]# ./startCluster.sh 
>>> Creating cluster
Connecting to node 192.168.1.115:7001: OK
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.1.115:7001 
192.168.1.115:7002 
192.168.1.115:7003
..............
..............
Can I set the above configuration? (type 'yes' to accept): yes
.............
.............
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

这种情况发生在每次非正常关闭redis集群的时候

2.集群（主、从）节点添加报该错误解决办法：
错误原因：如果原来该结点在集群中的配置信息已经生成到cluster-config-file指定的配置文件中（如果cluster-config-file没有指定则默认为nodes.conf），这时可能会报错：
[ERR] Node XXXXXX is not empty. Either the node already knows other nodes (check with CLUSTER NODES) or contains some key in database 0

解决方法：删除生成的配置文件nodes.conf，删除后再执行./redis-trib.rb add-node指令