/* * 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. */ /* * Copyright 2015 Cloudius Systems * * Modified by Cloudius Systems */ package org.apache.cassandra.gms; import java.net.UnknownHostException; import java.util.logging.Logger; import javax.ws.rs.core.MultivaluedHashMap; import javax.ws.rs.core.MultivaluedMap; import com.scylladb.jmx.api.APIClient; import com.scylladb.jmx.metrics.APIMBean; /** * This module is responsible for Gossiping information for the local endpoint. * This abstraction maintains the list of live and dead endpoints. Periodically * i.e. every 1 second this module chooses a random node and initiates a round * of Gossip with it. A round of Gossip involves 3 rounds of messaging. For * instance if node A wants to initiate a round of Gossip with node B it starts * off by sending node B a GossipDigestSynMessage. Node B on receipt of this * message sends node A a GossipDigestAckMessage. On receipt of this message * node A sends node B a GossipDigestAck2Message which completes a round of * Gossip. This module as and when it hears one of the three above mentioned * messages updates the Failure Detector with the liveness information. Upon * hearing a GossipShutdownMessage, this module will instantly mark the remote * node as down in the Failure Detector. */ public class Gossiper extends APIMBean implements GossiperMBean { public static final String MBEAN_NAME = "org.apache.cassandra.net:type=Gossiper"; private static final Logger logger = Logger.getLogger(Gossiper.class.getName()); public Gossiper(APIClient c) { super(c); } public void log(String str) { logger.finest(str); } @Override public long getEndpointDowntime(String address) throws UnknownHostException { log(" getEndpointDowntime(String address) throws UnknownHostException"); return client.getLongValue("gossiper/downtime/" + address); } @Override public int getCurrentGenerationNumber(String address) throws UnknownHostException { log(" getCurrentGenerationNumber(String address) throws UnknownHostException"); return client.getIntValue("gossiper/generation_number/" + address); } @Override public void unsafeAssassinateEndpoint(String address) throws UnknownHostException { log(" unsafeAssassinateEndpoint(String address) throws UnknownHostException"); MultivaluedMap queryParams = new MultivaluedHashMap(); queryParams.add("unsafe", "True"); client.post("gossiper/assassinate/" + address, queryParams); } @Override public void assassinateEndpoint(String address) throws UnknownHostException { log(" assassinateEndpoint(String address) throws UnknownHostException"); client.post("gossiper/assassinate/" + address, null); } }