Nodes joining or leaving the cluster

Elastic Stack Elasticsearch
1

Starting in Elastic 2, the node event "node_left" and "node_joined" have been removed from marvel indexes. Is there any other way to create a watch to alert when a node joins or leaves the cluster? Besides doing a query for total nodes?

2

Hey,

a couple of possibilities (tested with 5.0.0-alpha3):

  • data of the type .monitoring/cluster_info contains a node count (same for cluster_stats)
  • data of type node in the monitoring indices contain node information, albeit no timestamp to filter for
  • The type node_stats contains a timestamp and a node_id/node name. This would allow you to execute one search with two aggregations for different time windows and aggregate on the node name. If the results differ, you can easily filter out the joined or left nodes using scripting

hope this helps

--Alex