Start transform APIedit

Starts a transform. It accepts a StartTransformRequest object and responds with a StartTransformResponse object.

Start transform requestedit

A StartTransformRequest object requires a non-null id.

StartTransformRequest request =
        new StartTransformRequest("mega-transform");  

Constructing a new start request referencing an existing transform

Optional argumentsedit

The following arguments are optional.


Controls the amount of time to wait until the transform starts.

Synchronous executionedit

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

StartTransformResponse response =
                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 executionedit

Executing a StartTransformRequest 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 start-transform method:

        request, RequestOptions.DEFAULT, listener); 

The StartTransformRequest 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 start-transform looks like:

ActionListener<StartTransformResponse> listener =
        new ActionListener<StartTransformResponse>() {
            public void onResponse(
                    StartTransformResponse response) {

            public void onFailure(Exception e) {

Called when the execution is successfully completed.

Called when the whole StartTransformRequest fails.


The returned StartTransformResponse object acknowledges the transform has started.