org.apache.hadoop.hdfs.server.balancer.BalancingPolicy Maven / Gradle / Ivy
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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.
*/
package org.apache.hadoop.hdfs.server.balancer;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.StorageType;
import org.apache.hadoop.hdfs.server.protocol.DatanodeStorageReport;
import org.apache.hadoop.hdfs.server.protocol.StorageReport;
import org.apache.hadoop.hdfs.util.EnumCounters;
import org.apache.hadoop.hdfs.util.EnumDoubles;
/**
* Balancing policy.
* Since a datanode may contain multiple block pools,
* {@link Pool} implies {@link Node}
* but NOT the other way around
*/
@InterfaceAudience.Private
abstract class BalancingPolicy {
final EnumCounters totalCapacities
= new EnumCounters(StorageType.class);
final EnumCounters totalUsedSpaces
= new EnumCounters(StorageType.class);
final EnumDoubles avgUtilizations
= new EnumDoubles(StorageType.class);
void reset() {
totalCapacities.reset();
totalUsedSpaces.reset();
avgUtilizations.reset();
}
/** Get the policy name. */
abstract String getName();
/** Accumulate used space and capacity. */
abstract void accumulateSpaces(DatanodeStorageReport r);
void initAvgUtilization() {
for(StorageType t : StorageType.asList()) {
final long capacity = totalCapacities.get(t);
if (capacity > 0L) {
final double avg = totalUsedSpaces.get(t)*100.0/capacity;
avgUtilizations.set(t, avg);
}
}
}
double getAvgUtilization(StorageType t) {
return avgUtilizations.get(t);
}
/** @return the utilization of a particular storage type of a datanode;
* or return null if the datanode does not have such storage type.
*/
abstract Double getUtilization(DatanodeStorageReport r, StorageType t);
@Override
public String toString() {
return BalancingPolicy.class.getSimpleName()
+ "." + getClass().getSimpleName();
}
/** Get all {@link BalancingPolicy} instances*/
static BalancingPolicy parse(String s) {
final BalancingPolicy [] all = {BalancingPolicy.Node.INSTANCE,
BalancingPolicy.Pool.INSTANCE};
for(BalancingPolicy p : all) {
if (p.getName().equalsIgnoreCase(s))
return p;
}
throw new IllegalArgumentException("Cannot parse string \"" + s + "\"");
}
/**
* Cluster is balanced if each node is balanced.
*/
static class Node extends BalancingPolicy {
static final Node INSTANCE = new Node();
private Node() {}
@Override
String getName() {
return "datanode";
}
@Override
void accumulateSpaces(DatanodeStorageReport r) {
for(StorageReport s : r.getStorageReports()) {
final StorageType t = s.getStorage().getStorageType();
totalCapacities.add(t, s.getCapacity());
totalUsedSpaces.add(t, s.getDfsUsed());
}
}
@Override
Double getUtilization(DatanodeStorageReport r, final StorageType t) {
long capacity = 0L;
long dfsUsed = 0L;
for(StorageReport s : r.getStorageReports()) {
if (s.getStorage().getStorageType() == t) {
capacity += s.getCapacity();
dfsUsed += s.getDfsUsed();
}
}
return capacity == 0L? null: dfsUsed*100.0/capacity;
}
}
/**
* Cluster is balanced if each pool in each node is balanced.
*/
static class Pool extends BalancingPolicy {
static final Pool INSTANCE = new Pool();
private Pool() {}
@Override
String getName() {
return "blockpool";
}
@Override
void accumulateSpaces(DatanodeStorageReport r) {
for(StorageReport s : r.getStorageReports()) {
final StorageType t = s.getStorage().getStorageType();
totalCapacities.add(t, s.getCapacity());
totalUsedSpaces.add(t, s.getBlockPoolUsed());
}
}
@Override
Double getUtilization(DatanodeStorageReport r, final StorageType t) {
long capacity = 0L;
long blockPoolUsed = 0L;
for(StorageReport s : r.getStorageReports()) {
if (s.getStorage().getStorageType() == t) {
capacity += s.getCapacity();
blockPoolUsed += s.getBlockPoolUsed();
}
}
return capacity == 0L? null: blockPoolUsed*100.0/capacity;
}
}
}
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