IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.

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Cluster Administration

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Cluster Administration

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To access cluster Java API, you need to call cluster() method from an AdminClient:

ClusterAdminClient clusterAdminClient = client.admin().cluster();

In the rest of this guide, we will use client.admin().cluster().

Cluster Health

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Health

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The cluster health API allows to get a very simple status on the health of the cluster and also can give you some technical information about the cluster status per index:

ClusterHealthResponse healths = client.admin().cluster().prepareHealth().get(); 
String clusterName = healths.getClusterName();              
int numberOfDataNodes = healths.getNumberOfDataNodes();     
int numberOfNodes = healths.getNumberOfNodes();             

for (ClusterIndexHealth health : healths.getIndices().values()) { 
    String index = health.getIndex();                       
    int numberOfShards = health.getNumberOfShards();        
    int numberOfReplicas = health.getNumberOfReplicas();    
    ClusterHealthStatus status = health.getStatus();        
}

	Get information for all indices
	Access the cluster name
	Get the total number of data nodes
	Get the total number of nodes
	Iterate over all indices
	Index name
	Number of shards
	Number of replicas
	Index status

Wait for status

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You can use the cluster health API to wait for a specific status for the whole cluster or for a given index:

client.admin().cluster().prepareHealth()            
        .setWaitForYellowStatus()                   
        .get();
client.admin().cluster().prepareHealth("company")   
        .setWaitForGreenStatus()                    
        .get();

client.admin().cluster().prepareHealth("employee")  
        .setWaitForGreenStatus()                    
        .setTimeout(TimeValue.timeValueSeconds(2))  
        .get();

	Prepare a health request
	Wait for the cluster being yellow
	Prepare the health request for index `company`
	Wait for the index being green
	Prepare the health request for index `employee`
	Wait for the index being green
	Wait at most for 2 seconds

If the index does not have the expected status and you want to fail in that case, you need to explicitly interpret the result:

ClusterHealthResponse response = client.admin().cluster().prepareHealth("company")
        .setWaitForGreenStatus()    
        .get();

ClusterHealthStatus status = response.getIndices().get("company").getStatus();
if (!status.equals(ClusterHealthStatus.GREEN)) {
    throw new RuntimeException("Index is in " + status + " state"); 
}

	Wait for the index being green
	Throw an exception if not `GREEN`

Stored Scripts API

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The stored script API allows one to interact with scripts and templates stored in Elasticsearch. It can be used to create, update, get, and delete stored scripts and templates.

PutStoredScriptResponse response = client.admin().cluster().preparePutStoredScript()
                .setId("script1")
                .setContent(new BytesArray("{\"script\": {\"lang\": \"painless\", \"source\": \"_score * doc['my_numeric_field'].value\"} }"), XContentType.JSON)
                .get();

GetStoredScriptResponse response = client().admin().cluster().prepareGetStoredScript()
                .setId("script1")
                .get();

DeleteStoredScriptResponse response = client().admin().cluster().prepareDeleteStoredScript()
                .setId("script1")
                .get();

To store templates simply use "mustache" for the scriptLang.

Script Language

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The put stored script API allows one to set the language of the stored script. If one is not provided the default scripting language will be used.

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