cat masteredit

master doesn’t have any extra options. It simply displays the master’s node ID, bound IP address, and node name. For example:

GET /_cat/master?v

might respond:

id                     host      ip        node
YzWoH_2BT-6UjVGDyPdqYg YzWoH_2

This information is also available via the nodes command, but this is slightly shorter when all you want to do, for example, is verify all nodes agree on the master:

% pssh -i -h list.of.cluster.hosts curl -s localhost:9200/_cat/master
[1] 19:16:37 [SUCCESS] es3.vm
Ntgn2DcuTjGuXlhKDUD4vA H5dfFeA
[2] 19:16:37 [SUCCESS] es2.vm
Ntgn2DcuTjGuXlhKDUD4vA H5dfFeA
[3] 19:16:37 [SUCCESS] es1.vm
Ntgn2DcuTjGuXlhKDUD4vA H5dfFeA