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/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.cluster.routing;
import com.carrotsearch.hppc.IntSet;
import com.carrotsearch.hppc.cursors.IntCursor;
import com.carrotsearch.hppc.cursors.IntObjectCursor;
import org.apache.lucene.util.CollectionUtil;
import org.elasticsearch.cluster.AbstractDiffable;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.common.Randomness;
import org.elasticsearch.common.collect.ImmutableOpenIntMap;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.shard.ShardId;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
/**
* The {@link IndexRoutingTable} represents routing information for a single
* index. The routing table maintains a list of all shards in the index. A
* single shard in this context has one more instances namely exactly one
* {@link ShardRouting#primary() primary} and 1 or more replicas. In other
* words, each instance of a shard is considered a replica while only one
* replica per shard is a primary replica. The primary replica
* can be seen as the "leader" of the shard acting as the primary entry point
* for operations on a specific shard.
*
* Note: The term replica is not directly
* reflected in the routing table or in releated classes, replicas are
* represented as {@link ShardRouting}.
*
*/
public class IndexRoutingTable extends AbstractDiffable implements Iterable {
public static final IndexRoutingTable PROTO = builder(new Index("", "_na_")).build();
private final Index index;
private final ShardShuffler shuffler;
// note, we assume that when the index routing is created, ShardRoutings are created for all possible number of
// shards with state set to UNASSIGNED
private final ImmutableOpenIntMap shards;
private final List allActiveShards;
IndexRoutingTable(Index index, ImmutableOpenIntMap shards) {
this.index = index;
this.shuffler = new RotationShardShuffler(Randomness.get().nextInt());
this.shards = shards;
List allActiveShards = new ArrayList<>();
for (IntObjectCursor cursor : shards) {
for (ShardRouting shardRouting : cursor.value) {
if (shardRouting.active()) {
allActiveShards.add(shardRouting);
}
}
}
this.allActiveShards = Collections.unmodifiableList(allActiveShards);
}
/**
* Return the index id
*
* @return id of the index
*/
public Index getIndex() {
return index;
}
boolean validate(MetaData metaData) {
// check index exists
if (!metaData.hasIndex(index.getName())) {
throw new IllegalStateException(index + " exists in routing does not exists in metadata");
}
IndexMetaData indexMetaData = metaData.index(index.getName());
if (indexMetaData.getIndexUUID().equals(index.getUUID()) == false) {
throw new IllegalStateException(index.getName() + " exists in routing does not exists in metadata with the same uuid");
}
// check the number of shards
if (indexMetaData.getNumberOfShards() != shards().size()) {
Set expected = new HashSet<>();
for (int i = 0; i < indexMetaData.getNumberOfShards(); i++) {
expected.add(i);
}
for (IndexShardRoutingTable indexShardRoutingTable : this) {
expected.remove(indexShardRoutingTable.shardId().id());
}
throw new IllegalStateException("Wrong number of shards in routing table, missing: " + expected);
}
// check the replicas
for (IndexShardRoutingTable indexShardRoutingTable : this) {
int routingNumberOfReplicas = indexShardRoutingTable.size() - 1;
if (routingNumberOfReplicas != indexMetaData.getNumberOfReplicas()) {
throw new IllegalStateException("Shard [" + indexShardRoutingTable.shardId().id() +
"] routing table has wrong number of replicas, expected [" + indexMetaData.getNumberOfReplicas() +
"], got [" + routingNumberOfReplicas + "]");
}
for (ShardRouting shardRouting : indexShardRoutingTable) {
if (!shardRouting.index().equals(index)) {
throw new IllegalStateException("shard routing has an index [" + shardRouting.index() + "] that is different " +
"from the routing table");
}
}
}
return true;
}
@Override
public Iterator iterator() {
return shards.valuesIt();
}
/**
* Calculates the number of nodes that hold one or more shards of this index
* {@link IndexRoutingTable} excluding the nodes with the node ids give as
* the excludedNodes parameter.
*
* @param excludedNodes id of nodes that will be excluded
* @return number of distinct nodes this index has at least one shard allocated on
*/
public int numberOfNodesShardsAreAllocatedOn(String... excludedNodes) {
Set nodes = new HashSet<>();
for (IndexShardRoutingTable shardRoutingTable : this) {
for (ShardRouting shardRouting : shardRoutingTable) {
if (shardRouting.assignedToNode()) {
String currentNodeId = shardRouting.currentNodeId();
boolean excluded = false;
if (excludedNodes != null) {
for (String excludedNode : excludedNodes) {
if (currentNodeId.equals(excludedNode)) {
excluded = true;
break;
}
}
}
if (!excluded) {
nodes.add(currentNodeId);
}
}
}
}
return nodes.size();
}
public ImmutableOpenIntMap shards() {
return shards;
}
public ImmutableOpenIntMap getShards() {
return shards();
}
public IndexShardRoutingTable shard(int shardId) {
return shards.get(shardId);
}
/**
* Returns true if all shards are primary and active. Otherwise false.
*/
public boolean allPrimaryShardsActive() {
return primaryShardsActive() == shards().size();
}
/**
* Calculates the number of primary shards in active state in routing table
*
* @return number of active primary shards
*/
public int primaryShardsActive() {
int counter = 0;
for (IndexShardRoutingTable shardRoutingTable : this) {
if (shardRoutingTable.primaryShard().active()) {
counter++;
}
}
return counter;
}
/**
* Returns true if all primary shards are in
* {@link ShardRoutingState#UNASSIGNED} state. Otherwise false.
*/
public boolean allPrimaryShardsUnassigned() {
return primaryShardsUnassigned() == shards.size();
}
/**
* Calculates the number of primary shards in the routing table the are in
* {@link ShardRoutingState#UNASSIGNED} state.
*/
public int primaryShardsUnassigned() {
int counter = 0;
for (IndexShardRoutingTable shardRoutingTable : this) {
if (shardRoutingTable.primaryShard().unassigned()) {
counter++;
}
}
return counter;
}
/**
* Returns a {@link List} of shards that match one of the states listed in {@link ShardRoutingState states}
*
* @param state {@link ShardRoutingState} to retrieve
* @return a {@link List} of shards that match one of the given {@link ShardRoutingState states}
*/
public List shardsWithState(ShardRoutingState state) {
List shards = new ArrayList<>();
for (IndexShardRoutingTable shardRoutingTable : this) {
shards.addAll(shardRoutingTable.shardsWithState(state));
}
return shards;
}
/**
* Returns an unordered iterator over all active shards (including replicas).
*/
public ShardsIterator randomAllActiveShardsIt() {
return new PlainShardsIterator(shuffler.shuffle(allActiveShards));
}
/**
* A group shards iterator where each group ({@link ShardIterator}
* is an iterator across shard replication group.
*/
public GroupShardsIterator groupByShardsIt() {
// use list here since we need to maintain identity across shards
ArrayList set = new ArrayList<>(shards.size());
for (IndexShardRoutingTable indexShard : this) {
set.add(indexShard.shardsIt());
}
return new GroupShardsIterator(set);
}
/**
* A groups shards iterator where each groups is a single {@link ShardRouting} and a group
* is created for each shard routing.
*
* This basically means that components that use the {@link GroupShardsIterator} will iterate
* over *all* the shards (all the replicas) within the index.
*/
public GroupShardsIterator groupByAllIt() {
// use list here since we need to maintain identity across shards
ArrayList set = new ArrayList<>();
for (IndexShardRoutingTable indexShard : this) {
for (ShardRouting shardRouting : indexShard) {
set.add(shardRouting.shardsIt());
}
}
return new GroupShardsIterator(set);
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
IndexRoutingTable that = (IndexRoutingTable) o;
if (!index.equals(that.index)) return false;
if (!shards.equals(that.shards)) return false;
return true;
}
@Override
public int hashCode() {
int result = index.hashCode();
result = 31 * result + shards.hashCode();
return result;
}
@Override
public IndexRoutingTable readFrom(StreamInput in) throws IOException {
Index index = new Index(in);
Builder builder = new Builder(index);
int size = in.readVInt();
for (int i = 0; i < size; i++) {
builder.addIndexShard(IndexShardRoutingTable.Builder.readFromThin(in, index));
}
return builder.build();
}
@Override
public void writeTo(StreamOutput out) throws IOException {
index.writeTo(out);
out.writeVInt(shards.size());
for (IndexShardRoutingTable indexShard : this) {
IndexShardRoutingTable.Builder.writeToThin(indexShard, out);
}
}
public static Builder builder(Index index) {
return new Builder(index);
}
public static class Builder {
private final Index index;
private final ImmutableOpenIntMap.Builder shards = ImmutableOpenIntMap.builder();
public Builder(Index index) {
this.index = index;
}
/**
* Reads an {@link IndexRoutingTable} from an {@link StreamInput}
*
* @param in {@link StreamInput} to read the {@link IndexRoutingTable} from
* @return {@link IndexRoutingTable} read
* @throws IOException if something happens during read
*/
public static IndexRoutingTable readFrom(StreamInput in) throws IOException {
return PROTO.readFrom(in);
}
/**
* Initializes a new empty index, as if it was created from an API.
*/
public Builder initializeAsNew(IndexMetaData indexMetaData) {
return initializeEmpty(indexMetaData, new UnassignedInfo(UnassignedInfo.Reason.INDEX_CREATED, null));
}
/**
* Initializes a new empty index, as if it was created from an API.
*/
public Builder initializeAsRecovery(IndexMetaData indexMetaData) {
return initializeEmpty(indexMetaData, new UnassignedInfo(UnassignedInfo.Reason.CLUSTER_RECOVERED, null));
}
/**
* Initializes a new index caused by dangling index imported.
*/
public Builder initializeAsFromDangling(IndexMetaData indexMetaData) {
return initializeEmpty(indexMetaData, new UnassignedInfo(UnassignedInfo.Reason.DANGLING_INDEX_IMPORTED, null));
}
/**
* Initializes a new empty index, as as a result of opening a closed index.
*/
public Builder initializeAsFromCloseToOpen(IndexMetaData indexMetaData) {
return initializeEmpty(indexMetaData, new UnassignedInfo(UnassignedInfo.Reason.INDEX_REOPENED, null));
}
/**
* Initializes a new empty index, to be restored from a snapshot
*/
public Builder initializeAsNewRestore(IndexMetaData indexMetaData, RestoreSource restoreSource, IntSet ignoreShards) {
final UnassignedInfo unassignedInfo = new UnassignedInfo(UnassignedInfo.Reason.NEW_INDEX_RESTORED,
"restore_source[" + restoreSource.snapshot().getRepository() + "/" +
restoreSource.snapshot().getSnapshotId().getName() + "]");
return initializeAsRestore(indexMetaData, restoreSource, ignoreShards, true, unassignedInfo);
}
/**
* Initializes an existing index, to be restored from a snapshot
*/
public Builder initializeAsRestore(IndexMetaData indexMetaData, RestoreSource restoreSource) {
final UnassignedInfo unassignedInfo = new UnassignedInfo(UnassignedInfo.Reason.EXISTING_INDEX_RESTORED,
"restore_source[" + restoreSource.snapshot().getRepository() + "/" +
restoreSource.snapshot().getSnapshotId().getName() + "]");
return initializeAsRestore(indexMetaData, restoreSource, null, false, unassignedInfo);
}
/**
* Initializes an index, to be restored from snapshot
*/
private Builder initializeAsRestore(IndexMetaData indexMetaData, RestoreSource restoreSource, IntSet ignoreShards, boolean asNew, UnassignedInfo unassignedInfo) {
assert indexMetaData.getIndex().equals(index);
if (!shards.isEmpty()) {
throw new IllegalStateException("trying to initialize an index with fresh shards, but already has shards created");
}
for (int shardNumber = 0; shardNumber < indexMetaData.getNumberOfShards(); shardNumber++) {
ShardId shardId = new ShardId(index, shardNumber);
IndexShardRoutingTable.Builder indexShardRoutingBuilder = new IndexShardRoutingTable.Builder(shardId);
for (int i = 0; i <= indexMetaData.getNumberOfReplicas(); i++) {
if (asNew && ignoreShards.contains(shardNumber)) {
// This shards wasn't completely snapshotted - restore it as new shard
indexShardRoutingBuilder.addShard(ShardRouting.newUnassigned(shardId, null, i == 0, unassignedInfo));
} else {
indexShardRoutingBuilder.addShard(ShardRouting.newUnassigned(shardId, i == 0 ? restoreSource : null, i == 0, unassignedInfo));
}
}
shards.put(shardNumber, indexShardRoutingBuilder.build());
}
return this;
}
/**
* Initializes a new empty index, with an option to control if its from an API or not.
*/
private Builder initializeEmpty(IndexMetaData indexMetaData, UnassignedInfo unassignedInfo) {
assert indexMetaData.getIndex().equals(index);
if (!shards.isEmpty()) {
throw new IllegalStateException("trying to initialize an index with fresh shards, but already has shards created");
}
for (int shardNumber = 0; shardNumber < indexMetaData.getNumberOfShards(); shardNumber++) {
ShardId shardId = new ShardId(index, shardNumber);
IndexShardRoutingTable.Builder indexShardRoutingBuilder = new IndexShardRoutingTable.Builder(shardId);
for (int i = 0; i <= indexMetaData.getNumberOfReplicas(); i++) {
indexShardRoutingBuilder.addShard(ShardRouting.newUnassigned(shardId, null, i == 0, unassignedInfo));
}
shards.put(shardNumber, indexShardRoutingBuilder.build());
}
return this;
}
public Builder addReplica() {
for (IntCursor cursor : shards.keys()) {
int shardNumber = cursor.value;
ShardId shardId = new ShardId(index, shardNumber);
// version 0, will get updated when reroute will happen
ShardRouting shard = ShardRouting.newUnassigned(shardId, null, false, new UnassignedInfo(UnassignedInfo.Reason.REPLICA_ADDED, null));
shards.put(shardNumber,
new IndexShardRoutingTable.Builder(shards.get(shard.id())).addShard(shard).build()
);
}
return this;
}
public Builder removeReplica() {
for (IntCursor cursor : shards.keys()) {
int shardId = cursor.value;
IndexShardRoutingTable indexShard = shards.get(shardId);
if (indexShard.replicaShards().isEmpty()) {
// nothing to do here!
return this;
}
// re-add all the current ones
IndexShardRoutingTable.Builder builder = new IndexShardRoutingTable.Builder(indexShard.shardId());
for (ShardRouting shardRouting : indexShard) {
builder.addShard(shardRouting);
}
// first check if there is one that is not assigned to a node, and remove it
boolean removed = false;
for (ShardRouting shardRouting : indexShard) {
if (!shardRouting.primary() && !shardRouting.assignedToNode()) {
builder.removeShard(shardRouting);
removed = true;
break;
}
}
if (!removed) {
for (ShardRouting shardRouting : indexShard) {
if (!shardRouting.primary()) {
builder.removeShard(shardRouting);
break;
}
}
}
shards.put(shardId, builder.build());
}
return this;
}
public Builder addIndexShard(IndexShardRoutingTable indexShard) {
shards.put(indexShard.shardId().id(), indexShard);
return this;
}
/**
* Adds a new shard routing (makes a copy of it), with reference data used from the index shard routing table
* if it needs to be created.
*/
public Builder addShard(ShardRouting shard) {
IndexShardRoutingTable indexShard = shards.get(shard.id());
if (indexShard == null) {
indexShard = new IndexShardRoutingTable.Builder(shard.shardId()).addShard(shard).build();
} else {
indexShard = new IndexShardRoutingTable.Builder(indexShard).addShard(shard).build();
}
shards.put(indexShard.shardId().id(), indexShard);
return this;
}
public IndexRoutingTable build() {
return new IndexRoutingTable(index, shards.build());
}
}
public String prettyPrint() {
StringBuilder sb = new StringBuilder("-- index [" + index + "]\n");
List ordered = new ArrayList<>();
for (IndexShardRoutingTable indexShard : this) {
ordered.add(indexShard);
}
CollectionUtil.timSort(ordered, (o1, o2) -> {
int v = o1.shardId().getIndex().getName().compareTo(
o2.shardId().getIndex().getName());
if (v == 0) {
v = Integer.compare(o1.shardId().id(),
o2.shardId().id());
}
return v;
});
for (IndexShardRoutingTable indexShard : ordered) {
sb.append("----shard_id [").append(indexShard.shardId().getIndex().getName()).append("][").append(indexShard.shardId().id()).append("]\n");
for (ShardRouting shard : indexShard) {
sb.append("--------").append(shard.shortSummary()).append("\n");
}
}
return sb.toString();
}
}
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