1. primary shard -- raid0
2.replicas shard -- raid1
3.index - library Library Guidelines
4.MySQL vs elasticsearch
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1.
curl GET http://10.0.0.92:9200/_cluster/health?level=indices
"CLUSTER_NAME": "ELK-Cluster", "Status": "Yellow"
Yellow represents all the main fragments are available, but not all copies of the fragments are available, the most common scenario is when a single node, due es default is 1 copy, and the copy of the master slice can not be on the same node, a copy is unassigned unassigned