Cluster Health
editCluster Health
editThe cluster health API allows to get a very simple status on the health of the cluster. For example, on a quiet single node cluster with a single index with 5 shards and one replica, this:
GET _cluster/health
Returns this:
{ "cluster_name" : "testcluster", "status" : "yellow", "timed_out" : false, "number_of_nodes" : 1, "number_of_data_nodes" : 1, "active_primary_shards" : 5, "active_shards" : 5, "relocating_shards" : 0, "initializing_shards" : 0, "unassigned_shards" : 5, "delayed_unassigned_shards": 0, "number_of_pending_tasks" : 0, "number_of_in_flight_fetch": 0, "task_max_waiting_in_queue_millis": 0, "active_shards_percent_as_number": 50.0 }
The API can also be executed against one or more indices to get just the specified indices health:
GET /_cluster/health/test1,test2
The cluster health status is: green
, yellow
or red
. On the shard
level, a red
status indicates that the specific shard is not allocated
in the cluster, yellow
means that the primary shard is allocated but
replicas are not, and green
means that all shards are allocated. The
index level status is controlled by the worst shard status. The cluster
status is controlled by the worst index status.
One of the main benefits of the API is the ability to wait until the
cluster reaches a certain high water-mark health level. For example, the
following will wait for 50 seconds for the cluster to reach the yellow
level (if it reaches the green
or yellow
status before 50 seconds elapse,
it will return at that point):
GET /_cluster/health?wait_for_status=yellow&timeout=50s
Request Parameters
editThe cluster health API accepts the following request parameters:
-
level
-
Can be one of
cluster
,indices
orshards
. Controls the details level of the health information returned. Defaults tocluster
. -
wait_for_status
-
One of
green
,yellow
orred
. Will wait (until the timeout provided) until the status of the cluster changes to the one provided or better, i.e.green
>yellow
>red
. By default, will not wait for any status. -
wait_for_no_relocating_shards
- A boolean value which controls whether to wait (until the timeout provided) for the cluster to have no shard relocations. Defaults to false, which means it will not wait for relocating shards.
-
wait_for_no_initializing_shards
- A boolean value which controls whether to wait (until the timeout provided) for the cluster to have no shard initializations. Defaults to false, which means it will not wait for initializing shards.
-
wait_for_active_shards
-
A number controlling to how many active shards to wait for,
all
to wait for all shards in the cluster to be active, or0
to not wait. Defaults to0
. -
wait_for_nodes
-
The request waits until the specified number
N
of nodes is available. It also accepts>=N
,<=N
,>N
and<N
. Alternatively, it is possible to usege(N)
,le(N)
,gt(N)
andlt(N)
notation. -
timeout
-
A time based parameter controlling how long to wait if one of
the wait_for_XXX are provided. Defaults to
30s
. -
local
-
If
true
returns the local node information and does not provide the state from master node. Default:false
.
The following is an example of getting the cluster health at the
shards
level:
GET /_cluster/health/twitter?level=shards