scylla-jmx/src/main/java/org/apache/cassandra/gms/Gossiper.java

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/*
* 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.lang.management.ManagementFactory;
import java.net.UnknownHostException;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.ws.rs.core.MultivaluedHashMap;
import javax.ws.rs.core.MultivaluedMap;
import com.scylladb.jmx.api.APIClient;
/**
* 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 implements GossiperMBean {
public static final String MBEAN_NAME = "org.apache.cassandra.net:type=Gossiper";
private static final java.util.logging.Logger logger = java.util.logging.Logger
.getLogger(Gossiper.class.getName());
private APIClient c = new APIClient();
public void log(String str) {
logger.finest(str);
}
private static final Gossiper instance = new Gossiper();
public static Gossiper getInstance() {
return instance;
}
private Gossiper() {
// Register this instance with JMX
try {
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
mbs.registerMBean(this, new ObjectName(MBEAN_NAME));
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public long getEndpointDowntime(String address) throws UnknownHostException {
log(" getEndpointDowntime(String address) throws UnknownHostException");
return c.getLongValue("gossiper/downtime/" + address);
}
public int getCurrentGenerationNumber(String address)
throws UnknownHostException {
log(" getCurrentGenerationNumber(String address) throws UnknownHostException");
return c.getIntValue("gossiper/generation_number/" + address);
}
public void unsafeAssassinateEndpoint(String address)
throws UnknownHostException {
log(" unsafeAssassinateEndpoint(String address) throws UnknownHostException");
MultivaluedMap<String, String> queryParams = new MultivaluedHashMap<String, String>();
queryParams.add("unsafe", "True");
c.post("gossiper/assassinate/" + address, queryParams);
}
public void assassinateEndpoint(String address) throws UnknownHostException {
log(" assassinateEndpoint(String address) throws UnknownHostException");
c.post("gossiper/assassinate/" + address, null);
}
}