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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 com.google.common.collect.ImmutableList;
import com.google.common.collect.Sets;
import com.google.common.collect.UnmodifiableIterator;
import org.elasticsearch.ElasticsearchIllegalStateException;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.common.collect.ImmutableOpenIntMap;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.index.shard.ShardId;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ThreadLocalRandom;
import static com.google.common.collect.Lists.newArrayList;
/**
* 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 <tt>primary</tt> replica. The <tt>primary</tt> replica
* can be seen as the "leader" of the shard acting as the primary entry point
* for operations on a specific shard.
* <p>
* Note: The term replica is not directly
* reflected in the routing table or in releated classes, replicas are
* represented as {@link ShardRouting}.
* </p>
*/
public class IndexRoutingTable implements Iterable<IndexShardRoutingTable> {
private final String 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<IndexShardRoutingTable> shards;
private final ImmutableList<ShardRouting> allShards;
private final ImmutableList<ShardRouting> allActiveShards;
IndexRoutingTable(String index, ImmutableOpenIntMap<IndexShardRoutingTable> shards) {
this.index = index;
this.shuffler = new RotationShardShuffler(ThreadLocalRandom.current().nextInt());
this.shards = shards;
ImmutableList.Builder<ShardRouting> allShards = ImmutableList.builder();
ImmutableList.Builder<ShardRouting> allActiveShards = ImmutableList.builder();
for (IntObjectCursor<IndexShardRoutingTable> cursor : shards) {
for (ShardRouting shardRouting : cursor.value) {
allShards.add(shardRouting);
if (shardRouting.active()) {
allActiveShards.add(shardRouting);
}
}
}
this.allShards = allShards.build();
this.allActiveShards = allActiveShards.build();
}
/**
* Return the index id
*
* @return id of the index
*/
public String index() {
return this.index;
}
/**
* Return the index id
*
* @return id of the index
*/
public String getIndex() {
return index();
}
/**
* creates a new {@link IndexRoutingTable} with all shard versions normalized
*
* @return new {@link IndexRoutingTable}
*/
public IndexRoutingTable normalizeVersions() {
IndexRoutingTable.Builder builder = new Builder(this.index);
for (IntObjectCursor<IndexShardRoutingTable> cursor : shards) {
builder.addIndexShard(cursor.value.normalizeVersions());
}
return builder.build();
}
public void validate(RoutingTableValidation validation, MetaData metaData) {
if (!metaData.hasIndex(index())) {
validation.addIndexFailure(index(), "Exists in routing does not exists in metadata");
return;
}
IndexMetaData indexMetaData = metaData.index(index());
for (String failure : validate(indexMetaData)) {
validation.addIndexFailure(index, failure);
}
}
/**
* validate based on a meta data, returning failures found
*/
public List<String> validate(IndexMetaData indexMetaData) {
ArrayList<String> failures = new ArrayList<>();
// check the number of shards
if (indexMetaData.numberOfShards() != shards().size()) {
Set<Integer> expected = Sets.newHashSet();
for (int i = 0; i < indexMetaData.numberOfShards(); i++) {
expected.add(i);
}
for (IndexShardRoutingTable indexShardRoutingTable : this) {
expected.remove(indexShardRoutingTable.shardId().id());
}
failures.add("Wrong number of shards in routing table, missing: " + expected);
}
// check the replicas
for (IndexShardRoutingTable indexShardRoutingTable : this) {
int routingNumberOfReplicas = indexShardRoutingTable.size() - 1;
if (routingNumberOfReplicas != indexMetaData.numberOfReplicas()) {
failures.add("Shard [" + indexShardRoutingTable.shardId().id()
+ "] routing table has wrong number of replicas, expected [" + indexMetaData.numberOfReplicas() + "], got [" + routingNumberOfReplicas + "]");
}
for (ShardRouting shardRouting : indexShardRoutingTable) {
if (!shardRouting.index().equals(index())) {
failures.add("shard routing has an index [" + shardRouting.index() + "] that is different than the routing table");
}
}
}
return failures;
}
@Override
public UnmodifiableIterator<IndexShardRoutingTable> 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 <code>excludedNodes</code> 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<String> nodes = Sets.newHashSet();
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<IndexShardRoutingTable> shards() {
return shards;
}
public ImmutableOpenIntMap<IndexShardRoutingTable> getShards() {
return shards();
}
public IndexShardRoutingTable shard(int shardId) {
return shards.get(shardId);
}
/**
* Returns <code>true</code> if all shards are primary and active. Otherwise <code>false</code>.
*/
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 <code>true</code> if all primary shards are in
* {@link ShardRoutingState#UNASSIGNED} state. Otherwise <code>false</code>.
*/
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 states a set of {@link ShardRoutingState states}
* @return a {@link List} of shards that match one of the given {@link ShardRoutingState states}
*/
public List<ShardRouting> shardsWithState(ShardRoutingState... states) {
List<ShardRouting> shards = newArrayList();
for (IndexShardRoutingTable shardRoutingTable : this) {
shards.addAll(shardRoutingTable.shardsWithState(states));
}
return shards;
}
/**
* Returns an unordered iterator over all shards (including replicas).
*/
public ShardsIterator randomAllShardsIt() {
return new PlainShardsIterator(shuffler.shuffle(allShards));
}
/**
* 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<ShardIterator> 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.
* <p/>
* <p>This basically means that components that use the {@link GroupShardsIterator} will iterate
* over *all* the shards (all the replicas) within the index.</p>
*/
public GroupShardsIterator groupByAllIt() {
// use list here since we need to maintain identity across shards
ArrayList<ShardIterator> set = new ArrayList<>();
for (IndexShardRoutingTable indexShard : this) {
for (ShardRouting shardRouting : indexShard) {
set.add(shardRouting.shardsIt());
}
}
return new GroupShardsIterator(set);
}
public void validate() throws RoutingValidationException {
}
public static Builder builder(String index) {
return new Builder(index);
}
public static class Builder {
private final String index;
private final ImmutableOpenIntMap.Builder<IndexShardRoutingTable> shards = ImmutableOpenIntMap.builder();
public Builder(String 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 {
String index = in.readString();
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();
}
/**
* Writes an {@link IndexRoutingTable} to a {@link StreamOutput}.
*
* @param index {@link IndexRoutingTable} to write
* @param out {@link StreamOutput} to write to
* @throws IOException if something happens during write
*/
public static void writeTo(IndexRoutingTable index, StreamOutput out) throws IOException {
out.writeString(index.index());
out.writeVInt(index.shards.size());
for (IndexShardRoutingTable indexShard : index) {
IndexShardRoutingTable.Builder.writeToThin(indexShard, out);
}
}
/**
* Initializes a new empty index, as if it was created from an API.
*/
public Builder initializeAsNew(IndexMetaData indexMetaData) {
return initializeEmpty(indexMetaData, true);
}
/**
* Initializes a new empty index, as if it was created from an API.
*/
public Builder initializeAsRecovery(IndexMetaData indexMetaData) {
return initializeEmpty(indexMetaData, false);
}
/**
* Initializes a new empty index, to be restored from a snapshot
*/
public Builder initializeAsNewRestore(IndexMetaData indexMetaData, RestoreSource restoreSource, IntSet ignoreShards) {
return initializeAsRestore(indexMetaData, restoreSource, ignoreShards, true);
}
/**
* Initializes an existing index, to be restored from a snapshot
*/
public Builder initializeAsRestore(IndexMetaData indexMetaData, RestoreSource restoreSource) {
return initializeAsRestore(indexMetaData, restoreSource, null, false);
}
/**
* Initializes an index, to be restored from snapshot
*/
private Builder initializeAsRestore(IndexMetaData indexMetaData, RestoreSource restoreSource, IntSet ignoreShards, boolean asNew) {
if (!shards.isEmpty()) {
throw new ElasticsearchIllegalStateException("trying to initialize an index with fresh shards, but already has shards created");
}
for (int shardId = 0; shardId < indexMetaData.numberOfShards(); shardId++) {
IndexShardRoutingTable.Builder indexShardRoutingBuilder = new IndexShardRoutingTable.Builder(new ShardId(indexMetaData.index(), shardId), asNew ? false : true);
for (int i = 0; i <= indexMetaData.numberOfReplicas(); i++) {
if (asNew && ignoreShards.contains(shardId)) {
// This shards wasn't completely snapshotted - restore it as new shard
indexShardRoutingBuilder.addShard(new ImmutableShardRouting(index, shardId, null, i == 0, ShardRoutingState.UNASSIGNED, 0));
} else {
indexShardRoutingBuilder.addShard(new ImmutableShardRouting(index, shardId, null, null, i == 0 ? restoreSource : null, i == 0, ShardRoutingState.UNASSIGNED, 0));
}
}
shards.put(shardId, 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, boolean asNew) {
if (!shards.isEmpty()) {
throw new ElasticsearchIllegalStateException("trying to initialize an index with fresh shards, but already has shards created");
}
for (int shardId = 0; shardId < indexMetaData.numberOfShards(); shardId++) {
IndexShardRoutingTable.Builder indexShardRoutingBuilder = new IndexShardRoutingTable.Builder(new ShardId(indexMetaData.index(), shardId), asNew ? false : true);
for (int i = 0; i <= indexMetaData.numberOfReplicas(); i++) {
indexShardRoutingBuilder.addShard(new ImmutableShardRouting(index, shardId, null, i == 0, ShardRoutingState.UNASSIGNED, 0));
}
shards.put(shardId, indexShardRoutingBuilder.build());
}
return this;
}
public Builder addReplica() {
for (IntCursor cursor : shards.keys()) {
int shardId = cursor.value;
// version 0, will get updated when reroute will happen
ImmutableShardRouting shard = new ImmutableShardRouting(index, shardId, null, false, ShardRoutingState.UNASSIGNED, 0);
shards.put(shardId,
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(), indexShard.primaryAllocatedPostApi());
for (ShardRouting shardRouting : indexShard) {
builder.addShard(new ImmutableShardRouting(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);
removed = true;
break;
}
}
}
shards.put(shardId, builder.build());
}
return this;
}
public Builder addIndexShard(IndexShardRoutingTable indexShard) {
shards.put(indexShard.shardId().id(), indexShard);
return this;
}
/**
* Clears the post allocation flag for the specified shard
*/
public Builder clearPostAllocationFlag(ShardId shardId) {
assert this.index.equals(shardId.index().name());
IndexShardRoutingTable indexShard = shards.get(shardId.id());
shards.put(indexShard.shardId().id(), new IndexShardRoutingTable(indexShard.shardId(), indexShard.shards(), false));
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(IndexShardRoutingTable refData, ShardRouting shard) {
IndexShardRoutingTable indexShard = shards.get(shard.id());
if (indexShard == null) {
indexShard = new IndexShardRoutingTable.Builder(refData.shardId(), refData.primaryAllocatedPostApi()).addShard(new ImmutableShardRouting(shard)).build();
} else {
indexShard = new IndexShardRoutingTable.Builder(indexShard).addShard(new ImmutableShardRouting(shard)).build();
}
shards.put(indexShard.shardId().id(), indexShard);
return this;
}
public IndexRoutingTable build() throws RoutingValidationException {
IndexRoutingTable indexRoutingTable = new IndexRoutingTable(index, shards.build());
indexRoutingTable.validate();
return indexRoutingTable;
}
}
public String prettyPrint() {
StringBuilder sb = new StringBuilder("-- index [" + index + "]\n");
for (IndexShardRoutingTable indexShard : this) {
sb.append("----shard_id [").append(indexShard.shardId().index().name()).append("][").append(indexShard.shardId().id()).append("]\n");
for (ShardRouting shard : indexShard) {
sb.append("--------").append(shard.shortSummary()).append("\n");
}
}
return sb.toString();
}
}