/**
* 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.Arrays;
import java.util.Collection;
import java.util.concurrent.atomic.AtomicInteger;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.Multimap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.db.Table;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.thrift.ConsistencyLevel;
import org.apache.cassandra.thrift.UnavailableException;
/**
* Handles blocking writes for ONE, ANY, QUORUM, and ALL consistency levels.
*/
public class WriteResponseHandler extends AbstractWriteResponseHandler
{
protected static final Logger logger = LoggerFactory.getLogger(WriteResponseHandler.class);
protected final AtomicInteger responses;
protected WriteResponseHandler(Collection<InetAddress> writeEndpoints, Multimap<InetAddress, InetAddress> hintedEndpoints, ConsistencyLevel consistencyLevel, String table)
{
super(writeEndpoints, hintedEndpoints, consistencyLevel);
responses = new AtomicInteger(determineBlockFor(table));
}
protected WriteResponseHandler(InetAddress endpoint)
{
super(Arrays.asList(endpoint),
ImmutableMultimap.<InetAddress, InetAddress>builder().put(endpoint, endpoint).build(),
ConsistencyLevel.ALL);
responses = new AtomicInteger(1);
}
public static IWriteResponseHandler create(Collection<InetAddress> writeEndpoints, Multimap<InetAddress, InetAddress> hintedEndpoints, ConsistencyLevel consistencyLevel, String table)
{
return new WriteResponseHandler(writeEndpoints, hintedEndpoints, consistencyLevel, table);
}
public static IWriteResponseHandler create(InetAddress endpoint)
{
return new WriteResponseHandler(endpoint);
}
public void response(Message m)
{
if (responses.decrementAndGet() == 0)
condition.signal();
}
protected int determineBlockFor(String table)
{
int blockFor = 0;
switch (consistencyLevel)
{
case ONE:
blockFor = 1;
break;
case ANY:
blockFor = 1;
break;
case QUORUM:
blockFor = (writeEndpoints.size() / 2) + 1;
break;
case ALL:
blockFor = writeEndpoints.size();
break;
default:
throw new UnsupportedOperationException("invalid consistency level: " + consistencyLevel.toString());
}
// at most one node per range can bootstrap at a time, and these will be added to the write until
// bootstrap finishes (at which point we no longer need to write to the old ones).
assert 1 <= blockFor && blockFor <= 2 * Table.open(table).getReplicationStrategy().getReplicationFactor()
: String.format("invalid response count %d for replication factor %d",
blockFor, Table.open(table).getReplicationStrategy().getReplicationFactor());
return blockFor;
}
public void assureSufficientLiveNodes() throws UnavailableException
{
if (consistencyLevel == ConsistencyLevel.ANY)
{
// ensure there are blockFor distinct living nodes (hints are ok).
if (hintedEndpoints.keySet().size() < responses.get())
throw new UnavailableException();
}
// count destinations that are part of the desired target set
int liveNodes = 0;
for (InetAddress destination : hintedEndpoints.keySet())
{
if (writeEndpoints.contains(destination))
liveNodes++;
}
if (liveNodes < responses.get())
{
throw new UnavailableException();
}
}
public boolean isLatencyForSnitch()
{
return false;
}
}