curl http://127.0.0.1:9200/_cat/health?v
Cluster state (status): red red cluster represented unavailable faulty. yellow yellow represents the cluster is available, but not reliable, when this state is typically a single node. green normal state, the cluster represents everything is normal.
Nodes (node.total): number of nodes, here two, indicating that the cluster has two nodes.
Data nodes (node.data): data storage nodes, here 2. Data node Elasticsearch Concepts there.
Fractal (Shards) sheet: This is a 12, showing how we put the data into memory blocks.
Master slice number (pri): primary shards, here it is 6, is actually twice the number of fragments, because there is a copy, if there are two copies, the number here should be three times the number of fragments, this will fractal index sheet with the latter association, where only a total number.
Activated fragmentation percentage (active_shards_percent): here can be understood as the number of fragmented data loading, only load all of the number of fragments, clusters considered normal start, in the process of starting, if we continue to refresh this page, we will find this percentage will continue to increase.