elasticsearch/docs/java-rest/high-level/cluster/health.asciidoc

[[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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request]
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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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-indices-ctr]
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Or using the corresponding setter method:

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-indices-setter]
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==== Other parameters

Other parameters can be passed only through setter methods:

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-timeout]
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<1> Timeout for the request as a `TimeValue`. Defaults to 30 seconds
<2> As a `String`

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-master-timeout]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-status]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-events]
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<1> The priority of the events to wait for. Accepts a `Priority` value.

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-level]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-relocation]
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<1> Wait for 0 relocating shards. Defaults to `false`

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-initializing]
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<1> Wait for 0 initializing shards. Defaults to `false`

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-nodes]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-wait-active]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-request-local]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-execute]
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[[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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-execute-async]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-execute-listener]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-general]
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<1> Name of the cluster
<2> Cluster status (`green`, `yellow` or `red`)

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-request-status]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-nodes]
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<1> Number of nodes in the cluster
<2> Number of data nodes in the cluster

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-shards]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-task]
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<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"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-indices]
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<1> Detailed information about indices in the cluster

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-index]
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<1> Detailed information about a specific index

["source","java",subs="attributes,callouts,macros"]
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include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[health-response-shard-details]
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<1> Detailed information about a specific shard