[[cluster-health]] === Cluster health API ++++ Cluster health ++++ Returns the health status of a cluster. [[cluster-health-api-request]] ==== {api-request-title} `GET _cluster/health/` [[cluster-health-api-desc]] ==== {api-description-title} The cluster health API returns a simple status on the health of the cluster. You can also use the API to get the health status of only specified data streams and indices. For data streams, the API retrieves the health status of the stream's backing indices. 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): [source,console] -------------------------------------------------- GET /_cluster/health?wait_for_status=yellow&timeout=50s -------------------------------------------------- [[cluster-health-api-path-params]] ==== {api-path-parms-title} ``:: (Optional, string) Comma-separated list of data streams, indices, and index aliases used to limit the request. Wildcard expressions (`*`) are supported. + To target all data streams and indices in a cluster, omit this parameter or use `_all` or `*`. [[cluster-health-api-query-params]] ==== {api-query-parms-title} `level`:: (Optional, string) Can be one of `cluster`, `indices` or `shards`. Controls the details level of the health information returned. Defaults to `cluster`. include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=local] include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=timeoutparms] `wait_for_active_shards`:: (Optional, string) A number controlling to how many active shards to wait for, `all` to wait for all shards in the cluster to be active, or `0` to not wait. Defaults to `0`. `wait_for_events`:: (Optional, string) Can be one of `immediate`, `urgent`, `high`, `normal`, `low`, `languid`. Wait until all currently queued events with the given priority are processed. `wait_for_no_initializing_shards`:: (Optional, boolean) 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_no_relocating_shards`:: (Optional, boolean) 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_nodes`:: (Optional, string) The request waits until the specified number `N` of nodes is available. It also accepts `>=N`, `<=N`, `>N` and ` `yellow` > `red`. By default, will not wait for any status. [[cluster-health-api-response-body]] ==== {api-response-body-title} `cluster_name`:: (string) The name of the cluster. `status`:: include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=cluster-health-status] `timed_out`:: (boolean) If `false` the response returned within the period of time that is specified by the `timeout` parameter (`30s` by default). `number_of_nodes`:: (integer) The number of nodes within the cluster. `number_of_data_nodes`:: (integer) The number of nodes that are dedicated data nodes. `active_primary_shards`:: (integer) The number of active primary shards. `active_shards`:: (integer) The total number of active primary and replica shards. `relocating_shards`:: (integer) The number of shards that are under relocation. `initializing_shards`:: (integer) The number of shards that are under initialization. `unassigned_shards`:: (integer) The number of shards that are not allocated. `delayed_unassigned_shards`:: (integer) The number of shards whose allocation has been delayed by the timeout settings. `number_of_pending_tasks`:: (integer) The number of cluster-level changes that have not yet been executed. `number_of_in_flight_fetch`:: (integer) The number of unfinished fetches. `task_max_waiting_in_queue_millis`:: (integer) The time expressed in milliseconds since the earliest initiated task is waiting for being performed. `active_shards_percent_as_number`:: (float) The ratio of active shards in the cluster expressed as a percentage. [[cluster-health-api-example]] ==== {api-examples-title} [source,console] -------------------------------------------------- GET _cluster/health -------------------------------------------------- // TEST[s/^/PUT test1\n/] The API returns the following response in case of a quiet single node cluster with a single index with one shard and one replica: [source,console-result] -------------------------------------------------- { "cluster_name" : "testcluster", "status" : "yellow", "timed_out" : false, "number_of_nodes" : 1, "number_of_data_nodes" : 1, "active_primary_shards" : 1, "active_shards" : 1, "relocating_shards" : 0, "initializing_shards" : 0, "unassigned_shards" : 1, "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 } -------------------------------------------------- // TESTRESPONSE[s/testcluster/integTest/] // TESTRESPONSE[s/"number_of_pending_tasks" : 0,/"number_of_pending_tasks" : $body.number_of_pending_tasks,/] // TESTRESPONSE[s/"task_max_waiting_in_queue_millis": 0/"task_max_waiting_in_queue_millis": $body.task_max_waiting_in_queue_millis/] The following is an example of getting the cluster health at the `shards` level: [source,console] -------------------------------------------------- GET /_cluster/health/twitter?level=shards -------------------------------------------------- // TEST[setup:twitter]