Github user aledsage commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/908#discussion_r157783869
--- Diff:
core/src/main/java/org/apache/brooklyn/enricher/stock/aggregator/DashboardAggregator.java
---
@@ -0,0 +1,81 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.brooklyn.enricher.stock.aggregator;
+
+import java.util.Map;
+import java.util.concurrent.Callable;
+
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.mgmt.Task;
+import org.apache.brooklyn.core.enricher.AbstractEnricher;
+import org.apache.brooklyn.core.mgmt.BrooklynTaskTags;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensorAndConfigKey;
+import org.apache.brooklyn.util.core.task.ScheduledTask;
+import org.apache.brooklyn.util.core.task.Tasks;
+import org.apache.brooklyn.util.time.Duration;
+
+/**
+ * The DashboardAggregator is an enricher that combines config/sensor
values from the children of the entity it is attached to.
+ * The combined values are set as sensors on the entity that it is
attached to. Preference is given to the child entities sensors values,
+ * but if none are set, config values are used instead.
+ *
+ * The reason that this exists is to provide high level summary
information, that could be useful to display on a dashboard.
+ * Whilst brooklyn itself has no such dashboard, we can imagine this
entity being used in that fashion.
+ *
+ * Please note, that the DashboardAggregator will aggregate all children
of the entity it is attached to, even intermediate level children.
+ * Therefore, please only ever attach one DashboardAggregator to the top
most entity.
+ *
+ * For a detailed list of the config that is combined, please see the
AggregationJob class.
+ *
+ */
+public class DashboardAggregator extends AbstractEnricher {
+
+ private ScheduledTask task;
+
+ public static BasicAttributeSensorAndConfigKey<Duration>
DASHBOARD_COST_PER_MONTH = new BasicAttributeSensorAndConfigKey(Duration.class,
+ "dashboard.period",
+ "The amount of time to wait between aggregation jobs",
+ Duration.seconds(1));
+
+ @SuppressWarnings("unchecked")
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+
+ Duration duration = config().get(DASHBOARD_COST_PER_MONTH);
+
+ Callable<Task<?>> taskFactory = () -> Tasks.builder()
+ .dynamic(false)
+ .body(new AggregationJob(entity))
+ .displayName("DashboardAggregator task")
+ .tag(BrooklynTaskTags.TRANSIENT_TASK_TAG)
+ .description("Retrieves and aggregates sensor values")
+ .build();
+
+ task =
ScheduledTask.builder(taskFactory).period(duration).displayName("scheduled:[DashboardAggregator
task]").tagTransient().build();
+ this.getManagementContext().getExecutionManager().submit(task);
+
+ }
+
+ @Override
+ public void destroy() {
+ super.destroy();
+ task.cancel();
--- End diff --
guard with `if (task != null)`.
---
