Kylo publishes events to a message bus that you can subscribe to and react to changes in the system with custom plugins.

Below is a listing of the events Kylo publishes.

Event Description
CategoryChangeEvent Called when a Category is created, updated, or deleted
FeedChangeEvent Called when a Feed is created, updated, or deleted
FeedPropertyChangeEvent Called when a user updates the generic set of properties on a feed. See the Nifi processor PutFeedMetadata
PreconditionTriggerEvent Called when a precondition is fired for a feed
CleanupTriggerEvent Called when a feed is being cleaned up after a delete
FeedOperationStatusEvent Called when a Job for a feed has started, stopped, succeeded, failed, or been abandoned
TemplateChangeEvent Called when a Template is created, updated, or deleted
ServiceLevelAgreementEvent As of Kylo 0.8.4, Called only when an SLA is deleted.

Event Source

All events extends the AbstractMetadataEvent object. You can find relevant source code for the events here:

Example Feed Change Listener

import com.thinkbiganalytics.metadata.api.event.MetadataChange;
import com.thinkbiganalytics.metadata.api.event.MetadataEventListener;
import com.thinkbiganalytics.metadata.api.event.MetadataEventService;
import com.thinkbiganalytics.metadata.api.event.feed.FeedChangeEvent;
import com.thinkbiganalytics.metadata.api.event.feed.FeedOperationStatusEvent;
import com.thinkbiganalytics.metadata.api.feed.Feed;
import com.thinkbiganalytics.metadata.api.op.FeedOperation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import java.util.Optional;

import javax.annotation.Nonnull;
import javax.annotation.PostConstruct;
import javax.inject.Inject;

public class ExampleFeedListener {

    private static final Logger log = LoggerFactory.getLogger(ExampleFeedListener.class);

    private MetadataEventService metadataEventService;

     * Listen for when feeds change
    private final MetadataEventListener<FeedChangeEvent> feedPropertyChangeListener = new FeedChangeEventDispatcher();

     * Listen for when feed job executions change
    private final MetadataEventListener<FeedOperationStatusEvent> feedJobEventListener = new FeedJobEventListener();

    public void addEventListener() {

    private class FeedChangeEventDispatcher implements MetadataEventListener<FeedChangeEvent> {

        public void notify(@Nonnull final FeedChangeEvent metadataEvent) {

            //feedName will be the 'categorySystemName.feedSystemName'
            Optional<String> feedName = metadataEvent.getData().getFeedName();

            //the id for the feed
            Feed.ID feedId = metadataEvent.getData().getFeedId();

            //feed state will be NEW, ENABLED, DISABLED, DELETED
            Feed.State feedState = metadataEvent.getData().getFeedState();

            if (feedName.isPresent()) {
      "Feed {} ({}) has been {} ", feedName.get(), feedId, metadataEvent.getData().getChange());
                Feed.State state = metadataEvent.getData().getFeedState();
                if (metadataEvent.getData().getChange() == MetadataChange.ChangeType.CREATE) {
                    //Do something on Create
                } else if (metadataEvent.getData().getChange() == MetadataChange.ChangeType.UPDATE) {
                    //Do something on Update
                } else if (metadataEvent.getData().getChange() == MetadataChange.ChangeType.DELETE) {
                    //Do something on Delete


    private class FeedJobEventListener implements MetadataEventListener<FeedOperationStatusEvent> {

        public void notify(FeedOperationStatusEvent event) {

            //feedName will be the 'categorySystemName.feedSystemName'
            String feedName = event.getData().getFeedName();

            //the id for the feed
            Feed.ID feedId = event.getData().getFeedId();

            //This is the Job Execution Id
            FeedOperation.ID jobId = event.getData().getOperationId();

            FeedOperation.State jobState = event.getData().getState();

            //this is CHECK  or  FEED.   CHECK refers to a Data Confidence Job
            FeedOperation.FeedType feedType = event.getData().getFeedType();

            //a string message of what the event is for
            String statusMessage = event.getData().getStatus();

            if(event.getData().getState() == FeedOperation.State.SUCCESS){
                // Do something if a Job successfully completes