We are working on updating this book for the latest version. Some content might be out of date.
cluster-stats API provides similar output to the
node-stats. There is
one crucial difference: Node Stats shows you statistics per node, while
cluster-stats shows you the sum total of all nodes in a single metric.
This provides some useful stats to glance at. You can see for example, that your
entire cluster is using 50% of the available heap or that filter cache is not
evicting heavily. Its main use is to provide a quick summary that is more
extensive than the
cluster-health, but less detailed than
node-stats. It is
also useful for clusters that are very large, which makes
difficult to read.
The API may be invoked as follows: