[[java-rest-high-cluster-health]] === Cluster Health API The Cluster Health API allows getting cluster health. [[java-rest-high-cluster-health-request]] ==== Cluster Health Request A `ClusterHealthRequest`: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request] -------------------------------------------------- There are no required parameters. By default, the client will check all indices and will not wait for any events. ==== Indices Indices which should be checked can be passed in the constructor: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-indices-ctr] -------------------------------------------------- Or using the corresponding setter method: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-indices-setter] -------------------------------------------------- ==== Other parameters Other parameters can be passed only through setter methods: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-timeout] -------------------------------------------------- <1> Timeout for the request as a `TimeValue`. Defaults to 30 seconds <2> As a `String` ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-master-timeout] -------------------------------------------------- <1> Timeout to connect to the master node as a `TimeValue`. Defaults to the same as `timeout` <2> As a `String` ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-status] -------------------------------------------------- <1> The status to wait (e.g. `green`, `yellow`, or `red`). Accepts a `ClusterHealthStatus` value. <2> Using predefined method ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-events] -------------------------------------------------- <1> The priority of the events to wait for. Accepts a `Priority` value. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-level] -------------------------------------------------- <1> The level of detail of the returned health information. Accepts a `ClusterHealthRequest.Level` value. Default value is `cluster`. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-relocation] -------------------------------------------------- <1> Wait for 0 relocating shards. Defaults to `false` ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-initializing] -------------------------------------------------- <1> Wait for 0 initializing shards. Defaults to `false` ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-nodes] -------------------------------------------------- <1> Wait for `N` nodes in the cluster. Defaults to `0` <2> Using `>=N`, `<=N`, `>N` and `<N` notation <3> Using `ge(N)`, `le(N)`, `gt(N)`, `lt(N)` notation ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-active] -------------------------------------------------- <1> Wait for all shards to be active in the cluster <2> Wait for `N` shards to be active in the cluster ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-local] -------------------------------------------------- <1> Non-master node can be used for this request. Defaults to `false` [[java-rest-high-cluster-health-sync]] ==== Synchronous Execution ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-execute] -------------------------------------------------- [[java-rest-high-cluster-health-async]] ==== Asynchronous Execution The asynchronous execution of a cluster health request requires both the `ClusterHealthRequest` instance and an `ActionListener` instance to be passed to the asynchronous method: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-execute-async] -------------------------------------------------- <1> The `ClusterHealthRequest` to execute and the `ActionListener` to use when the execution completes The asynchronous method does not block and returns immediately. Once it is completed the `ActionListener` is called back using the `onResponse` method if the execution successfully completed or using the `onFailure` method if it failed. A typical listener for `ClusterHealthResponse` looks like: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-execute-listener] -------------------------------------------------- <1> Called when the execution is successfully completed. The response is provided as an argument <2> Called in case of a failure. The raised exception is provided as an argument [[java-rest-high-cluster-health-response]] ==== Cluster Health Response The returned `ClusterHealthResponse` contains the next information about the cluster: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-general] -------------------------------------------------- <1> Name of the cluster <2> Cluster status (`green`, `yellow` or `red`) ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-request-status] -------------------------------------------------- <1> Whether request was timed out while processing <2> Status of the request (`OK` or `REQUEST_TIMEOUT`). Other errors will be thrown as exceptions ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-nodes] -------------------------------------------------- <1> Number of nodes in the cluster <2> Number of data nodes in the cluster ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-shards] -------------------------------------------------- <1> Number of active shards <2> Number of primary active shards <3> Number of relocating shards <4> Number of initializing shards <5> Number of unassigned shards <6> Number of unassigned shards that are currently being delayed <7> Percent of active shards ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-task] -------------------------------------------------- <1> Maximum wait time of all tasks in the queue <2> Number of currently pending tasks <3> Number of async fetches that are currently ongoing ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-indices] -------------------------------------------------- <1> Detailed information about indices in the cluster ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-index] -------------------------------------------------- <1> Detailed information about a specific index ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-shard-details] -------------------------------------------------- <1> Detailed information about a specific shard