/**
* 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.ambari.server.events.listeners.alerts;
import java.util.Collection;
import java.util.Collections;
import org.apache.ambari.server.EagerSingleton;
import org.apache.ambari.server.agent.AlertDefinitionCommand;
import org.apache.ambari.server.agent.HeartBeatResponse;
import org.apache.ambari.server.events.AlertHashInvalidationEvent;
import org.apache.ambari.server.events.AmbariEvent.AmbariEventType;
import org.apache.ambari.server.events.ClusterEvent;
import org.apache.ambari.server.events.ServiceComponentUninstalledEvent;
import org.apache.ambari.server.events.publishers.AmbariEventPublisher;
import org.apache.ambari.server.state.alert.AlertDefinitionHash;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.eventbus.AllowConcurrentEvents;
import com.google.common.eventbus.Subscribe;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
/**
* The {@link AlertHashInvalidationListener} is used to respond to
* {@link AlertHashInvalidationEvent} and {@link ClusterEvent} instances and
* ensure that the {@link AlertDefinitionCommand}s are enqueued for the
* {@link HeartBeatResponse}.
* <p/>
* <ul>
* <li>{@link ClusterEvent} - invalidates all alerts across the cluster</li>
* <li>{@link AlertHashInvalidationEvent} - invalidates a specific alert across
* affected hosts</li>
* </ul>
*/
@Singleton
@EagerSingleton
public class AlertHashInvalidationListener {
/**
* Logger.
*/
private static Logger LOG = LoggerFactory.getLogger(AlertHashInvalidationListener.class);
/**
* Invalidates hosts so that they can receive updated alert definition
* commands.
*/
@Inject
private Provider<AlertDefinitionHash> m_alertDefinitionHash;
/**
* Constructor.
*
* @param publisher
*/
@Inject
public AlertHashInvalidationListener(AmbariEventPublisher publisher) {
publisher.register(this);
}
/**
* Handles {@link AlertHashInvalidationEvent} by performing the following
* tasks:
* <ul>
* <li>Enqueuing {@link AlertDefinitionCommand}</li>
* </ul>
*
* @param event
* the event being handled.
*/
@Subscribe
@AllowConcurrentEvents
public void onAmbariEvent(AlertHashInvalidationEvent event) {
LOG.debug("Received event {}", event);
Collection<String> hosts = event.getHosts();
long clusterId = event.getClusterId();
// no hosts, nothing to do
if (null == hosts || hosts.isEmpty()) {
return;
}
AlertDefinitionHash hash = m_alertDefinitionHash.get();
hash.enqueueAgentCommands(clusterId, hosts);
}
/**
* Handles {@link AlertHashInvalidationEvent} by performing the following
* tasks:
* <ul>
* <li>Alert has invalidation</li>
* <li>Enqueuing {@link AlertDefinitionCommand}</li>
* </ul>
*/
@Subscribe
@AllowConcurrentEvents
public void onEvent(ServiceComponentUninstalledEvent event) {
LOG.debug("Received event {}", event);
long clusterId = event.getClusterId();
String hostName = event.getHostName();
if (null == hostName) {
return;
}
// invalidate hash and enqueue commands
m_alertDefinitionHash.get().invalidate(hostName);
m_alertDefinitionHash.get().enqueueAgentCommands(clusterId,
Collections.singletonList(hostName));
}
/**
* Handles {@link ClusterEvent} by performing the following tasks:
* <ul>
* <li>Invalidates all alerts across all hosts. This is because agents use the
* cluster name as an identifier and if the cluster is renamed, then they need
* to be rescheduled.</li>
* </ul>
*
* @param event
* the event being handled.
*/
@Subscribe
@AllowConcurrentEvents
public void onAmbariEvent(ClusterEvent event) {
LOG.debug("Received event {}", event);
if( event.getType() != AmbariEventType.CLUSTER_RENAME ) {
return;
}
AlertDefinitionHash hash = m_alertDefinitionHash.get();
hash.invalidateAll();
long clusterId = event.getClusterId();
hash.enqueueAgentCommands(clusterId);
}
}