The cluster state API allows access to metadata representing the state of the whole cluster. This includes information such as
The response is an internal representation of the cluster state and its format may change from version to version. If possible, you should obtain any information from the cluster state using the other, more stable, cluster APIs.
GET /_cluster/state
The response provides the cluster state itself, which can be filtered to only retrieve the parts of interest as described below.
The cluster’s cluster_uuid
is also returned as part of the top-level response,
in addition to the metadata
section.
[6.4.0]
Added in 6.4.0.
While the cluster is still forming, it is possible for the cluster_uuid
to be _na_
as well as the cluster state’s version to be -1
.
By default, the cluster state request is routed to the master node, to ensure
that the latest cluster state is returned. For debugging purposes, you can
retrieve the cluster state local to a particular node by adding local=true
to
the query string.
The cluster state contains information about all the indices in the cluster, including their mappings, as well as templates and other metadata. This means it can sometimes be quite large. To avoid the need to process all this information you can request only the part of the cluster state that you need:
GET /_cluster/state/{metrics} GET /_cluster/state/{metrics}/{indices}
{metrics}
is a comma-separated list of the following options.
version
master_node
master_node
part of the response
nodes
nodes
part of the response
routing_table
routing_table
part of the response. If you supply a comma
separated list of indices, the returned output will only contain the routing
table for these indices.
metadata
metadata
part of the response. If you supply a comma separated
list of indices, the returned output will only contain metadata for these
indices.
blocks
blocks
part of the response.
_all
The following example returns only metadata
and routing_table
data for the
foo
and bar
indices:
GET /_cluster/state/metadata,routing_table/foo,bar
The next example returns everything for the foo
and bar
indices:
GET /_cluster/state/_all/foo,bar
Finally, this example return only the blocks
metadata:
GET /_cluster/state/blocks