/*
* 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.cassandra.service;
import java.net.InetAddress;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.Table;
import org.apache.cassandra.exceptions.UnavailableException;
import org.apache.cassandra.gms.FailureDetector;
import org.apache.cassandra.locator.IEndpointSnitch;
import org.apache.cassandra.locator.NetworkTopologyStrategy;
import org.apache.cassandra.net.MessageIn;
import org.apache.cassandra.db.ConsistencyLevel;
import org.apache.cassandra.utils.FBUtilities;
/**
* This class blocks for a quorum of responses _in all datacenters_ (CL.EACH_QUORUM).
*/
public class DatacenterSyncWriteResponseHandler extends AbstractWriteResponseHandler
{
private static final IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
private static final String localdc;
static
{
localdc = snitch.getDatacenter(FBUtilities.getBroadcastAddress());
}
private final String table;
private final NetworkTopologyStrategy strategy;
private final HashMap<String, AtomicInteger> responses = new HashMap<String, AtomicInteger>();
protected DatacenterSyncWriteResponseHandler(Collection<InetAddress> writeEndpoints, ConsistencyLevel consistencyLevel, String table, Runnable callback)
{
// Response is been managed by the map so make it 1 for the superclass.
super(writeEndpoints, consistencyLevel, callback);
assert consistencyLevel == ConsistencyLevel.EACH_QUORUM;
this.table = table;
strategy = (NetworkTopologyStrategy) Table.open(table).getReplicationStrategy();
for (String dc : strategy.getDatacenters())
{
int rf = strategy.getReplicationFactor(dc);
responses.put(dc, new AtomicInteger((rf / 2) + 1));
}
}
public static IWriteResponseHandler create(Collection<InetAddress> writeEndpoints, ConsistencyLevel consistencyLevel, String table, Runnable callback)
{
return new DatacenterSyncWriteResponseHandler(writeEndpoints, consistencyLevel, table, callback);
}
public void response(MessageIn message)
{
String dataCenter = message == null
? localdc
: snitch.getDatacenter(message.from);
responses.get(dataCenter).getAndDecrement();
for (AtomicInteger i : responses.values())
{
if (i.get() > 0)
return;
}
// all the quorum conditions are met
signal();
}
protected int blockFor()
{
return consistencyLevel.blockFor(table);
}
protected int ackCount()
{
int n = 0;
for (Map.Entry<String, AtomicInteger> entry : responses.entrySet())
{
String dc = entry.getKey();
AtomicInteger i = entry.getValue();
n += (strategy.getReplicationFactor(dc) / 2) + 1 - i.get();
}
return n;
}
public void assureSufficientLiveNodes() throws UnavailableException
{
Map<String, AtomicInteger> dcEndpoints = new HashMap<String, AtomicInteger>();
for (String dc: strategy.getDatacenters())
dcEndpoints.put(dc, new AtomicInteger());
for (InetAddress destination : writeEndpoints)
{
if (FailureDetector.instance.isAlive(destination))
{
// figure out the destination dc
String destinationDC = snitch.getDatacenter(destination);
dcEndpoints.get(destinationDC).incrementAndGet();
}
}
// Throw exception if any of the DC doesn't have livenodes to accept write.
for (String dc: strategy.getDatacenters())
{
if (dcEndpoints.get(dc).get() < responses.get(dc).get())
throw new UnavailableException(consistencyLevel, responses.get(dc).get(), dcEndpoints.get(dc).get());
}
}
public boolean isLatencyForSnitch()
{
return false;
}
}