| /* |
| * 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.bookkeeper.net; |
| |
| import io.netty.util.HashedWheelTimer; |
| import io.netty.util.Timeout; |
| import io.netty.util.TimerTask; |
| |
| import java.util.Collection; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * This is going to provide a stabilize network topology regarding to flapping zookeeper registration. |
| */ |
| public class StabilizeNetworkTopology implements NetworkTopology { |
| |
| private static final Logger logger = LoggerFactory.getLogger(StabilizeNetworkTopology.class); |
| |
| static class NodeStatus { |
| long lastPresentTime; |
| boolean tentativeToRemove; |
| |
| NodeStatus() { |
| this.lastPresentTime = System.currentTimeMillis(); |
| } |
| |
| synchronized boolean isTentativeToRemove() { |
| return tentativeToRemove; |
| } |
| |
| synchronized NodeStatus updateStatus(boolean tentativeToRemove) { |
| this.tentativeToRemove = tentativeToRemove; |
| if (!this.tentativeToRemove) { |
| this.lastPresentTime = System.currentTimeMillis(); |
| } |
| return this; |
| } |
| |
| synchronized long getLastPresentTime() { |
| return this.lastPresentTime; |
| } |
| } |
| |
| protected final NetworkTopologyImpl impl; |
| // timer |
| protected final HashedWheelTimer timer; |
| // statuses |
| protected final ConcurrentMap<Node, NodeStatus> nodeStatuses; |
| // stabilize period seconds |
| protected final long stabilizePeriodMillis; |
| |
| private class RemoveNodeTask implements TimerTask { |
| |
| private final Node node; |
| |
| RemoveNodeTask(Node node) { |
| this.node = node; |
| } |
| |
| @Override |
| public void run(Timeout timeout) throws Exception { |
| if (timeout.isCancelled()) { |
| return; |
| } |
| NodeStatus status = nodeStatuses.get(node); |
| if (null == status) { |
| // no status of this node, remove this node from topology |
| impl.remove(node); |
| } else if (status.isTentativeToRemove()) { |
| long millisSinceLastSeen = System.currentTimeMillis() - status.getLastPresentTime(); |
| if (millisSinceLastSeen >= stabilizePeriodMillis) { |
| logger.info("Node {} (seen @ {}) becomes stale for {} ms, remove it from the topology.", |
| node, status.getLastPresentTime(), millisSinceLastSeen); |
| impl.remove(node); |
| nodeStatuses.remove(node, status); |
| } |
| } |
| } |
| } |
| |
| public StabilizeNetworkTopology(HashedWheelTimer timer, |
| int stabilizePeriodSeconds) { |
| this.impl = new NetworkTopologyImpl(); |
| this.timer = timer; |
| this.nodeStatuses = new ConcurrentHashMap<Node, NodeStatus>(); |
| this.stabilizePeriodMillis = TimeUnit.SECONDS.toMillis(stabilizePeriodSeconds); |
| } |
| |
| void updateNode(Node node, boolean tentativeToRemove) { |
| NodeStatus ns = nodeStatuses.get(node); |
| if (null == ns) { |
| NodeStatus newStatus = new NodeStatus(); |
| NodeStatus oldStatus = nodeStatuses.putIfAbsent(node, newStatus); |
| if (null == oldStatus) { |
| ns = newStatus; |
| } else { |
| ns = oldStatus; |
| } |
| } |
| ns.updateStatus(tentativeToRemove); |
| } |
| |
| @Override |
| public void add(Node node) { |
| updateNode(node, false); |
| this.impl.add(node); |
| } |
| |
| @Override |
| public void remove(Node node) { |
| updateNode(node, true); |
| timer.newTimeout(new RemoveNodeTask(node), stabilizePeriodMillis, TimeUnit.MILLISECONDS); |
| } |
| |
| @Override |
| public boolean contains(Node node) { |
| return impl.contains(node); |
| } |
| |
| @Override |
| public Node getNode(String loc) { |
| return impl.getNode(loc); |
| } |
| |
| @Override |
| public int getNumOfRacks() { |
| return impl.getNumOfRacks(); |
| } |
| |
| @Override |
| public Set<Node> getLeaves(String loc) { |
| return impl.getLeaves(loc); |
| } |
| |
| @Override |
| public int countNumOfAvailableNodes(String scope, Collection<Node> excludedNodes) { |
| return impl.countNumOfAvailableNodes(scope, excludedNodes); |
| } |
| } |