Cluster Get Settings API

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The Cluster Get Settings API allows to get the cluster wide settings.

Cluster Get Settings Request

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A ClusterGetSettingsRequest:

ClusterGetSettingsRequest request = new ClusterGetSettingsRequest();

Optional arguments

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The following arguments can optionally be provided:

request.includeDefaults(true); 

By default only those settings that were explicitly set are returned. Setting this to true also returns the default settings.

request.local(true); 

By default the request goes to the master of the cluster to get the latest results. If local is specified it gets the results from whichever node the request goes to.

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

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

ClusterGetSettingsResponse response = client.cluster().getSettings(request, RequestOptions.DEFAULT); 

Asynchronous Execution

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Executing a ClusterGetSettingsRequest 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 get-settings method:

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

The ClusterGetSettingsRequest 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 get-settings looks like:

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

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

Called when the execution is successfully completed.

Called when the whole ClusterGetSettingsRequest fails.

Cluster Get Settings Response

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

Settings persistentSettings = response.getPersistentSettings(); 
Settings transientSettings = response.getTransientSettings(); 
Settings defaultSettings = response.getDefaultSettings(); 
String settingValue = response.getSetting("cluster.routing.allocation.enable"); 

Get the persistent settings.

Get the transient settings.

Get the default settings (returns empty settings if includeDefaults was not set to true).

Get the value as a String for a particular setting. The order of searching is first in persistentSettings then in transientSettings and finally, if not found in either, in defaultSettings.