IF Masternode fail/down how can we know? How can we check that?

Elastic Stack Elasticsearch
1

Hi,

If Masternode fail/down how can we know? How can we check that masternode is fail? any command/Plugin or Kibana?? Please share your knowledge.

2

Depends.
If you have a single master then your cluster will get a 500 response.
If you have multiples then use the _cat/master or _cat/nodes to detect changes.