Watcher Stats API

Execution

Watcher Stats returns the current Watcher metrics. Submit the following request to get the stats:

WatcherStatsRequest request = new WatcherStatsRequest(true, true);

Response

The returned AcknowledgeResponse contains a value on whether or not the request was received:

List<WatcherStatsResponse.Node> nodes = response.getNodes(); 

A boolean value of true if successfully received, false otherwise.

Synchronous Execution

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

WatcherStatsResponse response = client.watcher().watcherStats(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 WatcherStatsRequest 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 watcher-stats method:

client.watcher().watcherStatsAsync(request, RequestOptions.DEFAULT, listener); 

The WatcherStatsRequest 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 watcher-stats looks like:

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

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

Called when the execution is successfully completed.

Called when the whole WatcherStatsRequest fails.