org.apache.cassandra.locator.Replicas Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cassandra-all Show documentation
Show all versions of cassandra-all Show documentation
The Apache Cassandra Project develops a highly scalable second-generation distributed database, bringing together Dynamo's fully distributed design and Bigtable's ColumnFamily-based data model.
/*
* 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.locator;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.function.Predicate;
import com.carrotsearch.hppc.ObjectIntHashMap;
import com.carrotsearch.hppc.ObjectObjectHashMap;
import com.google.common.collect.Iterables;
import org.apache.cassandra.config.DatabaseDescriptor;
import static com.google.common.collect.Iterables.all;
public class Replicas
{
public static int countFull(ReplicaCollection replicas)
{
int count = 0;
for (Replica replica : replicas)
if (replica.isFull())
++count;
return count;
}
public static class ReplicaCount
{
int fullReplicas;
int transientReplicas;
public int allReplicas()
{
return fullReplicas + transientReplicas;
}
public int fullReplicas()
{
return fullReplicas;
}
public int transientReplicas()
{
return transientReplicas;
}
public void increment(Replica replica)
{
if (replica.isFull()) ++fullReplicas;
else ++transientReplicas;
}
public boolean hasAtleast(int allReplicas, int fullReplicas)
{
return this.fullReplicas >= fullReplicas
&& this.allReplicas() >= allReplicas;
}
}
public static ReplicaCount countInOurDc(ReplicaCollection replicas)
{
ReplicaCount count = new ReplicaCount();
Predicate inOurDc = InOurDc.replicas();
for (Replica replica : replicas)
if (inOurDc.test(replica))
count.increment(replica);
return count;
}
/**
* count the number of full and transient replicas, separately, for each DC
*/
public static ObjectObjectHashMap countPerDc(Collection dataCenters, Iterable replicas)
{
ObjectObjectHashMap perDc = new ObjectObjectHashMap<>(dataCenters.size());
for (String dc: dataCenters)
perDc.put(dc, new ReplicaCount());
IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
for (Replica replica : replicas)
{
String dc = snitch.getDatacenter(replica);
perDc.get(dc).increment(replica);
}
return perDc;
}
/**
* increment each of the map's DC entries for each matching replica provided
*/
public static void addToCountPerDc(ObjectIntHashMap perDc, Iterable replicas, int add)
{
IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
for (Replica replica : replicas)
{
String dc = snitch.getDatacenter(replica);
perDc.addTo(dc, add);
}
}
/**
* A placeholder for areas of the code that cannot yet handle transient replicas, but should do so in future
*/
public static void temporaryAssertFull(Replica replica)
{
if (!replica.isFull())
{
throw new UnsupportedOperationException("transient replicas are currently unsupported: " + replica);
}
}
/**
* A placeholder for areas of the code that cannot yet handle transient replicas, but should do so in future
*/
public static void temporaryAssertFull(Iterable replicas)
{
if (!all(replicas, Replica::isFull))
{
throw new UnsupportedOperationException("transient replicas are currently unsupported: " + Iterables.toString(replicas));
}
}
/**
* For areas of the code that should never see a transient replica
*/
public static void assertFull(Iterable replicas)
{
if (!all(replicas, Replica::isFull))
{
throw new UnsupportedOperationException("transient replicas are currently unsupported: " + Iterables.toString(replicas));
}
}
public static List stringify(ReplicaCollection replicas, boolean withPort)
{
List stringEndpoints = new ArrayList<>(replicas.size());
for (Replica replica: replicas)
{
stringEndpoints.add(replica.endpoint().getHostAddress(withPort));
}
return stringEndpoints;
}
}