What Does the Value i for node.roles Mean for Nodes in an Elasticsearch Cluster of CSS?

Function

If the value of node.roles of a client node is i, then is this client node an ingest node?

• Are there coordinating only nodes in clusters? Are the client requests distributed to coordinating nodes?
• Are ingest nodes in idle state when there are no ingest requests?

Solution

• The coordinating only nodes of Elasticsearch are called client nodes in CSS. If a cluster has no client nodes, client requests will be distributed to all nodes.
• An ingest node functions as a set of ELK for data conversion. If there is no ingest requests, ingest nodes are not in the idle state.