Elasticsearch cat Api (7.5 version)

1. cat Allocation: providing a snapshot of the number assigned to the fragments and disk space of each data node

　　A. 请求：GET /_cat/allocation/<node_id>  |  GET  /_cat/allocation

　　　　　Path parameter node_id: Node ID or name, separated by commas more;

　　B. query parameters

　　　　bytes: byte values for display units, the byte size of the unit ;

　　　　format: Specifies the type of response, with a text / json / smile / yaml / cbor the like, some formats may be specified by the Accept header http request, such as: application / json;　　　

　　　　h: column name to be displayed, a plurality of separated by commas;

　　　　v: If true, then the response column headings

　　C. Results Information