9 View interface - specific

1 View Aliases
View aliases as well as filter and routing information such as

GET /_cat/aliases?v

If you want to know some alias information, you can use

/_cat/aliases/alias1

2 Assign
the number of documents to view a cluster or an index

GET /_cat/count?v
GET /_cat/count/twitter?v

3 Number of documents
View the number of documents in a cluster or an index

GET /_cat/count?v
GET /_cat/count/twitter?v

4 Field data
How much memory is used by the current machine node to save field data (fielddata)

GET /_cat/fielddata?v

You can also filter based on the specific value of a column

GET /_cat/fielddata?v&fields=body

Or (I don't quite agree with it below, I can't confirm it locally)

GET /_cat/fielddata/body,soul?v

5 Health
Check the health of the current cluster

GET /_cat/health?v

6 Index
View all index situations

GET /_cat/indices?v
GET /_cat/indices/twieet

7 The main machine node
displays the main machine node information

/_cat/master?v

8 User-defined machine node information

GET /_cat/nodeattrs?v

You can also define and return to display those information according to h

GET /_cat/nodeattrs?v&h=name,pid,attr,value

9 Machine Topology

GET /_cat/nodes?v

10 Actions to be performed

GET /_cat/pending_tasks?v

11 Plugins
View the information of the plugins running on each machine node

GET /_cat/plugins?v&s=component&h=name,component,version,description

12 Data Recovery
Data recovery occurs as each data node moves. If a new machine joins the cluster, the number of replicas changes, the machine node crashes, and a new machine node joins.

curl -XGET 'localhost:9200/_cat/recovery?v'

13 Snapshot information
Display snapshot information library information

GET /_cat/repositories?v

14 thread pool
Display thread pool information for each machine node

curl /_cat/thread_pool

also through

get /_cat/thread_pool?help

To view all field information

15 data nodes
show the correspondence between each machine node and data node, as well as other information about each data node

curl 192.168.56.20:9200/_cat/shards

16 In the case of data fragmentation information
optimization, the number of each index fragmentation is preferably 1

GET /_cat/segments?v

18 templates to
display all template information

curl 'localhost:9200/_cat/templates?v