Get transform stats API

edit

Retrieves the operational statistics of one or more transforms. The API accepts a GetTransformStatsRequest object and returns a GetTransformStatsResponse.

Get transform stats request

edit

A GetTransformStatsRequest requires a transform id or the special wildcard _all to get the statistics for all transforms.

GetTransformStatsRequest request =
        new GetTransformStatsRequest(id); 

Constructing a new GET Stats request referencing an existing transform

Optional arguments

edit

The following arguments are optional.

request.setPageParams(new PageParams(0, 100)); 
request.setAllowNoMatch(true); 

The page parameters from and size. from specifies the number of transform stats to skip. size specifies the maximum number of transform stats to get. Defaults to 0 and 100 respectively.

Whether to ignore if a wildcard expression matches no transforms.

Synchronous execution

edit

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

GetTransformStatsResponse response =
    client.transform()
        .getTransformStats(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 GetTransformStatsRequest 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-transform-stats method:

client.transform().getTransformStatsAsync(
        request, RequestOptions.DEFAULT, listener);  

The GetTransformStatsRequest 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 get-transform-stats looks like:

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

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

Called when the execution is successfully completed.

Called when the whole GetTransformStatsRequest fails.

Response

edit

The returned GetTransformStatsResponse contains the requested transform statistics.

TransformStats stats =
    response.getTransformsStats().get(0); 
TransformStats.State state =
    stats.getState(); 
TransformIndexerStats indexerStats =
    stats.getIndexerStats(); 
TransformProgress progress =
    stats.getCheckpointingInfo()
        .getNext().getCheckpointProgress(); 
NodeAttributes node =
    stats.getNode(); 

The response contains a list of TransformStats objects

The running state of the transform, for example started, indexing, etc.

The overall transform statistics recording the number of documents indexed etc.

The progress of the current run in the transform. Supplies the number of docs left until the next checkpoint and the total number of docs expected.

The assigned node information if the task is currently assigned to a node and running.