ES集群中如果某个节点的磁盘空间使用率超过90%，则集群会自动转移该节点上的分片数据
high disk watermark [90%] exceeded on [jZ2N_EzKT5uDf474DxY6rA][test_Node3][/usr/share/elasticsearch/data/nodes/0] free: 2gb[5.6%], shards will be relocated away from this node; currently relocating away shards totalling [0] bytes; the node is expected to continue to exceed the high disk watermark when these relocations are complete