Cluster Update Settings API

The Cluster Update Settings API allows to update cluster wide settings.

Cluster Update Settings Request

A ClusterUpdateSettingsRequest:

ClusterUpdateSettingsRequest request = new ClusterUpdateSettingsRequest();

Cluster Settings

At least one setting to be updated must be provided:

request.transientSettings(transientSettings); 
request.persistentSettings(persistentSettings); 

Sets the transient settings to be applied

Sets the persistent setting to be applied

Providing the Settings

The settings to be applied can be provided in different ways:

String transientSettingKey =
        RecoverySettings.INDICES_RECOVERY_MAX_BYTES_PER_SEC_SETTING.getKey();
int transientSettingValue = 10;
Settings transientSettings =
        Settings.builder()
        .put(transientSettingKey, transientSettingValue, ByteSizeUnit.BYTES)
        .build(); 

String persistentSettingKey =
        EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey();
String persistentSettingValue =
        EnableAllocationDecider.Allocation.NONE.name();
Settings persistentSettings =
        Settings.builder()
        .put(persistentSettingKey, persistentSettingValue)
        .build(); 

Creates a transient setting as Settings

Creates a persistent setting as Settings

Settings.Builder transientSettingsBuilder =
        Settings.builder()
        .put(transientSettingKey, transientSettingValue, ByteSizeUnit.BYTES);
request.transientSettings(transientSettingsBuilder); 

Settings provided as Settings.Builder

request.transientSettings(
        "{\"indices.recovery.max_bytes_per_sec\": \"10b\"}"
        , XContentType.JSON); 

Settings provided as String

Map<String, Object> map = new HashMap<>();
map.put(transientSettingKey
        , transientSettingValue + ByteSizeUnit.BYTES.getSuffix());
request.transientSettings(map); 

Settings provided as a Map

Optional Arguments

The following arguments can optionally be provided:

request.timeout(TimeValue.timeValueMinutes(2)); 
request.timeout("2m"); 

Timeout to wait for the all the nodes to acknowledge the settings were applied as a TimeValue

Timeout to wait for the all the nodes to acknowledge the settings were applied as a String

request.masterNodeTimeout(TimeValue.timeValueMinutes(1)); 
request.masterNodeTimeout("1m"); 

Timeout to connect to the master node as a TimeValue

Timeout to connect to the master node as a String

Synchronous Execution

When executing a ClusterUpdateSettingsRequest in the following manner, the client waits for the ClusterUpdateSettingsResponse to be returned before continuing with code execution:

ClusterUpdateSettingsResponse response = client.cluster().putSettings(request, RequestOptions.DEFAULT);

Synchronous calls may throw an IOException in case of either failing to parse the REST response in the high-level REST client, the request times out or similar cases where there is no response coming back from the server.

In cases where the server returns a 4xx or 5xx error code, the high-level client tries to parse the response body error details instead and then throws a generic ElasticsearchException and adds the original ResponseException as a suppressed exception to it.

Asynchronous Execution

Executing a ClusterUpdateSettingsRequest can also be done in an asynchronous fashion so that the client can return directly. Users need to specify how the response or potential failures will be handled by passing the request and a listener to the asynchronous put-settings method:

client.cluster().putSettingsAsync(request, RequestOptions.DEFAULT, listener); 

The ClusterUpdateSettingsRequest 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. Failure scenarios and expected exceptions are the same as in the synchronous execution case.

A typical listener for put-settings looks like:

ActionListener<ClusterUpdateSettingsResponse> listener =
        new ActionListener<ClusterUpdateSettingsResponse>() {
    @Override
    public void onResponse(ClusterUpdateSettingsResponse response) {
        
    }

    @Override
    public void onFailure(Exception e) {
        
    }
};

Called when the execution is successfully completed.

Called when the whole ClusterUpdateSettingsRequest fails.

Cluster Update Settings Response

The returned ClusterUpdateSettingsResponse allows to retrieve information about the executed operation as follows:

boolean acknowledged = response.isAcknowledged(); 
Settings transientSettingsResponse = response.getTransientSettings(); 
Settings persistentSettingsResponse = response.getPersistentSettings(); 

Indicates whether all of the nodes have acknowledged the request

Indicates which transient settings have been applied

Indicates which persistent settings have been applied