Open Index API

edit

Open Index Request

edit

An OpenIndexRequest requires an index argument:

OpenIndexRequest request = new OpenIndexRequest("index"); 

The index to open

Optional arguments

edit

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 index is opened as a TimeValue

Timeout to wait for the all the nodes to acknowledge the index is opened 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

request.waitForActiveShards(2); 
request.waitForActiveShards(ActiveShardCount.DEFAULT); 

The number of active shard copies to wait for before the open index API returns a response, as an int

The number of active shard copies to wait for before the open index API returns a response, as an ActiveShardCount

request.indicesOptions(IndicesOptions.strictExpandOpen()); 

Setting IndicesOptions controls how unavailable indices are resolved and how wildcard expressions are expanded

Synchronous execution

edit

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

OpenIndexResponse openIndexResponse = client.indices().open(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

edit

Executing a OpenIndexRequest 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 open-index method:

client.indices().openAsync(request, RequestOptions.DEFAULT, listener); 

The OpenIndexRequest 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 open-index looks like:

ActionListener<OpenIndexResponse> listener =
        new ActionListener<OpenIndexResponse>() {
    @Override
    public void onResponse(OpenIndexResponse openIndexResponse) {
        
    }

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

Called when the execution is successfully completed.

Called when the whole OpenIndexRequest fails.

Open Index Response

edit

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

boolean acknowledged = openIndexResponse.isAcknowledged(); 
boolean shardsAcked = openIndexResponse.isShardsAcknowledged(); 

Indicates whether all of the nodes have acknowledged the request

Indicates whether the requisite number of shard copies were started for each shard in the index before timing out