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 127.0.0.1 127.0.0.1 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 192.168.56.30 H5dfFeA [2] 19:16:37 [SUCCESS] es2.vm Ntgn2DcuTjGuXlhKDUD4vA 192.168.56.30 H5dfFeA [3] 19:16:37 [SUCCESS] es1.vm Ntgn2DcuTjGuXlhKDUD4vA 192.168.56.30 H5dfFeA