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RoutingNodes.java
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RoutingNodes.java
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/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.cluster.routing;
import com.carrotsearch.hppc.ObjectIntHashMap;
import com.carrotsearch.hppc.cursors.ObjectCursor;
import org.apache.logging.log4j.Logger;
import org.apache.lucene.util.CollectionUtil;
import org.elasticsearch.Assertions;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.cluster.metadata.Metadata;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.UnassignedInfo.AllocationStatus;
import org.elasticsearch.cluster.routing.allocation.ExistingShardsAllocator;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.Randomness;
import org.elasticsearch.common.collect.Tuple;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.shard.ShardId;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.Set;
import java.util.function.Predicate;
/**
* {@link RoutingNodes} represents a copy the routing information contained in the {@link ClusterState cluster state}.
* It can be either initialized as mutable or immutable (see {@link #RoutingNodes(ClusterState, boolean)}), allowing
* or disallowing changes to its elements.
*
* The main methods used to update routing entries are:
* <ul>
* <li> {@link #initializeShard} initializes an unassigned shard.
* <li> {@link #startShard} starts an initializing shard / completes relocation of a shard.
* <li> {@link #relocateShard} starts relocation of a started shard.
* <li> {@link #failShard} fails/cancels an assigned shard.
* </ul>
*/
public class RoutingNodes implements Iterable<RoutingNode> {
private final Map<String, RoutingNode> nodesToShards = new HashMap<>();
private final UnassignedShards unassignedShards = new UnassignedShards(this);
private final Map<ShardId, List<ShardRouting>> assignedShards = new HashMap<>();
private final boolean readOnly;
private int inactivePrimaryCount = 0;
private int inactiveShardCount = 0;
private int relocatingShards = 0;
private final Map<String, ObjectIntHashMap<String>> nodesPerAttributeNames = new HashMap<>();
private final Map<String, Recoveries> recoveriesPerNode = new HashMap<>();
public RoutingNodes(ClusterState clusterState) {
this(clusterState, true);
}
public RoutingNodes(ClusterState clusterState, boolean readOnly) {
this.readOnly = readOnly;
final RoutingTable routingTable = clusterState.routingTable();
Map<String, LinkedHashMap<ShardId, ShardRouting>> nodesToShards = new HashMap<>();
// fill in the nodeToShards with the "live" nodes
for (ObjectCursor<DiscoveryNode> cursor : clusterState.nodes().getDataNodes().values()) {
nodesToShards.put(cursor.value.getId(), new LinkedHashMap<>()); // LinkedHashMap to preserve order
}
// fill in the inverse of node -> shards allocated
// also fill replicaSet information
for (ObjectCursor<IndexRoutingTable> indexRoutingTable : routingTable.indicesRouting().values()) {
for (IndexShardRoutingTable indexShard : indexRoutingTable.value) {
assert indexShard.primary != null;
for (ShardRouting shard : indexShard) {
// to get all the shards belonging to an index, including the replicas,
// we define a replica set and keep track of it. A replica set is identified
// by the ShardId, as this is common for primary and replicas.
// A replica Set might have one (and not more) replicas with the state of RELOCATING.
if (shard.assignedToNode()) {
Map<ShardId, ShardRouting> entries = nodesToShards.computeIfAbsent(shard.currentNodeId(),
k -> new LinkedHashMap<>()); // LinkedHashMap to preserve order
ShardRouting previousValue = entries.put(shard.shardId(), shard);
if (previousValue != null) {
throw new IllegalArgumentException("Cannot have two different shards with same shard id on same node");
}
assignedShardsAdd(shard);
if (shard.relocating()) {
relocatingShards++;
// LinkedHashMap to preserve order.
// Add the counterpart shard with relocatingNodeId reflecting the source from which
// it's relocating from.
entries = nodesToShards.computeIfAbsent(shard.relocatingNodeId(),
k -> new LinkedHashMap<>());
ShardRouting targetShardRouting = shard.getTargetRelocatingShard();
addInitialRecovery(targetShardRouting, indexShard.primary);
previousValue = entries.put(targetShardRouting.shardId(), targetShardRouting);
if (previousValue != null) {
throw new IllegalArgumentException("Cannot have two different shards with same shard id on same node");
}
assignedShardsAdd(targetShardRouting);
} else if (shard.initializing()) {
if (shard.primary()) {
inactivePrimaryCount++;
}
inactiveShardCount++;
addInitialRecovery(shard, indexShard.primary);
}
} else {
unassignedShards.add(shard);
}
}
}
}
for (Map.Entry<String, LinkedHashMap<ShardId, ShardRouting>> entry : nodesToShards.entrySet()) {
String nodeId = entry.getKey();
this.nodesToShards.put(nodeId, new RoutingNode(nodeId, clusterState.nodes().get(nodeId), entry.getValue()));
}
}
private void addRecovery(ShardRouting routing) {
updateRecoveryCounts(routing, true, findAssignedPrimaryIfPeerRecovery(routing));
}
private void removeRecovery(ShardRouting routing) {
updateRecoveryCounts(routing, false, findAssignedPrimaryIfPeerRecovery(routing));
}
private void addInitialRecovery(ShardRouting routing, ShardRouting initialPrimaryShard) {
updateRecoveryCounts(routing, true, initialPrimaryShard);
}
private void updateRecoveryCounts(final ShardRouting routing, final boolean increment, @Nullable final ShardRouting primary) {
final int howMany = increment ? 1 : -1;
assert routing.initializing() : "routing must be initializing: " + routing;
// TODO: check primary == null || primary.active() after all tests properly add ReplicaAfterPrimaryActiveAllocationDecider
assert primary == null || primary.assignedToNode() :
"shard is initializing but its primary is not assigned to a node";
Recoveries.getOrAdd(recoveriesPerNode, routing.currentNodeId()).addIncoming(howMany);
if (routing.recoverySource().getType() == RecoverySource.Type.PEER) {
// add/remove corresponding outgoing recovery on node with primary shard
if (primary == null) {
throw new IllegalStateException("shard is peer recovering but primary is unassigned");
}
Recoveries.getOrAdd(recoveriesPerNode, primary.currentNodeId()).addOutgoing(howMany);
if (increment == false && routing.primary() && routing.relocatingNodeId() != null) {
// primary is done relocating, move non-primary recoveries from old primary to new primary
int numRecoveringReplicas = 0;
for (ShardRouting assigned : assignedShards(routing.shardId())) {
if (assigned.primary() == false && assigned.initializing() &&
assigned.recoverySource().getType() == RecoverySource.Type.PEER) {
numRecoveringReplicas++;
}
}
recoveriesPerNode.get(routing.relocatingNodeId()).addOutgoing(-numRecoveringReplicas);
recoveriesPerNode.get(routing.currentNodeId()).addOutgoing(numRecoveringReplicas);
}
}
}
public int getIncomingRecoveries(String nodeId) {
return recoveriesPerNode.getOrDefault(nodeId, Recoveries.EMPTY).getIncoming();
}
public int getOutgoingRecoveries(String nodeId) {
return recoveriesPerNode.getOrDefault(nodeId, Recoveries.EMPTY).getOutgoing();
}
@Nullable
private ShardRouting findAssignedPrimaryIfPeerRecovery(ShardRouting routing) {
ShardRouting primary = null;
if (routing.recoverySource() != null && routing.recoverySource().getType() == RecoverySource.Type.PEER) {
List<ShardRouting> shardRoutings = assignedShards.get(routing.shardId());
if (shardRoutings != null) {
for (ShardRouting shardRouting : shardRoutings) {
if (shardRouting.primary()) {
if (shardRouting.active()) {
return shardRouting;
} else if (primary == null) {
primary = shardRouting;
} else if (primary.relocatingNodeId() != null) {
primary = shardRouting;
}
}
}
}
}
return primary;
}
@Override
public Iterator<RoutingNode> iterator() {
return Collections.unmodifiableCollection(nodesToShards.values()).iterator();
}
public Iterator<RoutingNode> mutableIterator() {
ensureMutable();
return nodesToShards.values().iterator();
}
public UnassignedShards unassigned() {
return this.unassignedShards;
}
public RoutingNode node(String nodeId) {
return nodesToShards.get(nodeId);
}
public ObjectIntHashMap<String> nodesPerAttributesCounts(String attributeName) {
ObjectIntHashMap<String> nodesPerAttributesCounts = nodesPerAttributeNames.get(attributeName);
if (nodesPerAttributesCounts != null) {
return nodesPerAttributesCounts;
}
nodesPerAttributesCounts = new ObjectIntHashMap<>();
for (RoutingNode routingNode : this) {
String attrValue = routingNode.node().getAttributes().get(attributeName);
if (attrValue != null) {
nodesPerAttributesCounts.addTo(attrValue, 1);
}
}
nodesPerAttributeNames.put(attributeName, nodesPerAttributesCounts);
return nodesPerAttributesCounts;
}
/**
* Returns <code>true</code> iff this {@link RoutingNodes} instance has any unassigned primaries even if the
* primaries are marked as temporarily ignored.
*/
public boolean hasUnassignedPrimaries() {
return unassignedShards.getNumPrimaries() + unassignedShards.getNumIgnoredPrimaries() > 0;
}
/**
* Returns <code>true</code> iff this {@link RoutingNodes} instance has any unassigned shards even if the
* shards are marked as temporarily ignored.
* @see UnassignedShards#isEmpty()
* @see UnassignedShards#isIgnoredEmpty()
*/
public boolean hasUnassignedShards() {
return unassignedShards.isEmpty() == false || unassignedShards.isIgnoredEmpty() == false;
}
public boolean hasInactivePrimaries() {
return inactivePrimaryCount > 0;
}
public boolean hasInactiveShards() {
return inactiveShardCount > 0;
}
public int getRelocatingShardCount() {
return relocatingShards;
}
/**
* Returns all shards that are not in the state UNASSIGNED with the same shard
* ID as the given shard.
*/
public List<ShardRouting> assignedShards(ShardId shardId) {
final List<ShardRouting> replicaSet = assignedShards.get(shardId);
return replicaSet == null ? EMPTY : Collections.unmodifiableList(replicaSet);
}
@Nullable
public ShardRouting getByAllocationId(ShardId shardId, String allocationId) {
final List<ShardRouting> replicaSet = assignedShards.get(shardId);
if (replicaSet == null) {
return null;
}
for (ShardRouting shardRouting : replicaSet) {
if (shardRouting.allocationId().getId().equals(allocationId)) {
return shardRouting;
}
}
return null;
}
/**
* Returns the active primary shard for the given shard id or <code>null</code> if
* no primary is found or the primary is not active.
*/
public ShardRouting activePrimary(ShardId shardId) {
for (ShardRouting shardRouting : assignedShards(shardId)) {
if (shardRouting.primary() && shardRouting.active()) {
return shardRouting;
}
}
return null;
}
/**
* Returns one active replica shard for the given shard id or <code>null</code> if
* no active replica is found.
*
* Since replicas could possibly be on nodes with a older version of ES than
* the primary is, this will return replicas on the highest version of ES.
*
*/
public ShardRouting activeReplicaWithHighestVersion(ShardId shardId) {
// It's possible for replicaNodeVersion to be null, when disassociating dead nodes
// that have been removed, the shards are failed, and part of the shard failing
// calls this method with an out-of-date RoutingNodes, where the version might not
// be accessible. Therefore, we need to protect against the version being null
// (meaning the node will be going away).
return assignedShards(shardId).stream()
.filter(shr -> shr.primary() == false && shr.active())
.filter(shr -> node(shr.currentNodeId()) != null)
.max(Comparator.comparing(shr -> node(shr.currentNodeId()).node(),
Comparator.nullsFirst(Comparator.comparing(DiscoveryNode::getVersion))))
.orElse(null);
}
/**
* Returns <code>true</code> iff all replicas are active for the given shard routing. Otherwise <code>false</code>
*/
public boolean allReplicasActive(ShardId shardId, Metadata metadata) {
final List<ShardRouting> shards = assignedShards(shardId);
if (shards.isEmpty() || shards.size() < metadata.getIndexSafe(shardId.getIndex()).getNumberOfReplicas() + 1) {
return false; // if we are empty nothing is active if we have less than total at least one is unassigned
}
for (ShardRouting shard : shards) {
if (shard.active() == false) {
return false;
}
}
return true;
}
public List<ShardRouting> shards(Predicate<ShardRouting> predicate) {
List<ShardRouting> shards = new ArrayList<>();
for (RoutingNode routingNode : this) {
for (ShardRouting shardRouting : routingNode) {
if (predicate.test(shardRouting)) {
shards.add(shardRouting);
}
}
}
return shards;
}
public List<ShardRouting> shardsWithState(ShardRoutingState... state) {
// TODO these are used on tests only - move into utils class
List<ShardRouting> shards = new ArrayList<>();
for (RoutingNode routingNode : this) {
shards.addAll(routingNode.shardsWithState(state));
}
for (ShardRoutingState s : state) {
if (s == ShardRoutingState.UNASSIGNED) {
unassigned().forEach(shards::add);
break;
}
}
return shards;
}
public List<ShardRouting> shardsWithState(String index, ShardRoutingState... state) {
// TODO these are used on tests only - move into utils class
List<ShardRouting> shards = new ArrayList<>();
for (RoutingNode routingNode : this) {
shards.addAll(routingNode.shardsWithState(index, state));
}
for (ShardRoutingState s : state) {
if (s == ShardRoutingState.UNASSIGNED) {
for (ShardRouting unassignedShard : unassignedShards) {
if (unassignedShard.index().getName().equals(index)) {
shards.add(unassignedShard);
}
}
break;
}
}
return shards;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder("routing_nodes:\n");
for (RoutingNode routingNode : this) {
sb.append(routingNode.prettyPrint());
}
sb.append("---- unassigned\n");
for (ShardRouting shardEntry : unassignedShards) {
sb.append("--------").append(shardEntry.shortSummary()).append('\n');
}
return sb.toString();
}
/**
* Moves a shard from unassigned to initialize state
*
* @param existingAllocationId allocation id to use. If null, a fresh allocation id is generated.
* @return the initialized shard
*/
public ShardRouting initializeShard(ShardRouting unassignedShard, String nodeId, @Nullable String existingAllocationId,
long expectedSize, RoutingChangesObserver routingChangesObserver) {
ensureMutable();
assert unassignedShard.unassigned() : "expected an unassigned shard " + unassignedShard;
ShardRouting initializedShard = unassignedShard.initialize(nodeId, existingAllocationId, expectedSize);
node(nodeId).add(initializedShard);
inactiveShardCount++;
if (initializedShard.primary()) {
inactivePrimaryCount++;
}
addRecovery(initializedShard);
assignedShardsAdd(initializedShard);
routingChangesObserver.shardInitialized(unassignedShard, initializedShard);
return initializedShard;
}
/**
* Relocate a shard to another node, adding the target initializing
* shard as well as assigning it.
*
* @return pair of source relocating and target initializing shards.
*/
public Tuple<ShardRouting,ShardRouting> relocateShard(ShardRouting startedShard, String nodeId, long expectedShardSize,
RoutingChangesObserver changes) {
ensureMutable();
relocatingShards++;
ShardRouting source = startedShard.relocate(nodeId, expectedShardSize);
ShardRouting target = source.getTargetRelocatingShard();
updateAssigned(startedShard, source);
node(target.currentNodeId()).add(target);
assignedShardsAdd(target);
addRecovery(target);
changes.relocationStarted(startedShard, target);
return Tuple.tuple(source, target);
}
/**
* Applies the relevant logic to start an initializing shard.
*
* Moves the initializing shard to started. If the shard is a relocation target, also removes the relocation source.
*
* If the started shard is a primary relocation target, this also reinitializes currently initializing replicas as their
* recovery source changes
*
* @return the started shard
*/
public ShardRouting startShard(Logger logger, ShardRouting initializingShard, RoutingChangesObserver routingChangesObserver) {
ensureMutable();
ShardRouting startedShard = started(initializingShard);
logger.trace("{} marked shard as started (routing: {})", initializingShard.shardId(), initializingShard);
routingChangesObserver.shardStarted(initializingShard, startedShard);
if (initializingShard.relocatingNodeId() != null) {
// relocation target has been started, remove relocation source
RoutingNode relocationSourceNode = node(initializingShard.relocatingNodeId());
ShardRouting relocationSourceShard = relocationSourceNode.getByShardId(initializingShard.shardId());
assert relocationSourceShard.isRelocationSourceOf(initializingShard);
assert relocationSourceShard.getTargetRelocatingShard() == initializingShard : "relocation target mismatch, expected: "
+ initializingShard + " but was: " + relocationSourceShard.getTargetRelocatingShard();
remove(relocationSourceShard);
routingChangesObserver.relocationCompleted(relocationSourceShard);
// if this is a primary shard with ongoing replica recoveries, reinitialize them as their recovery source changed
if (startedShard.primary()) {
List<ShardRouting> assignedShards = assignedShards(startedShard.shardId());
// copy list to prevent ConcurrentModificationException
for (ShardRouting routing : new ArrayList<>(assignedShards)) {
if (routing.initializing() && routing.primary() == false) {
if (routing.isRelocationTarget()) {
// find the relocation source
ShardRouting sourceShard = getByAllocationId(routing.shardId(), routing.allocationId().getRelocationId());
// cancel relocation and start relocation to same node again
ShardRouting startedReplica = cancelRelocation(sourceShard);
remove(routing);
routingChangesObserver.shardFailed(routing,
new UnassignedInfo(UnassignedInfo.Reason.REINITIALIZED, "primary changed"));
relocateShard(startedReplica, sourceShard.relocatingNodeId(),
sourceShard.getExpectedShardSize(), routingChangesObserver);
} else {
ShardRouting reinitializedReplica = reinitReplica(routing);
routingChangesObserver.initializedReplicaReinitialized(routing, reinitializedReplica);
}
}
}
}
}
return startedShard;
}
/**
* Applies the relevant logic to handle a cancelled or failed shard.
*
* Moves the shard to unassigned or completely removes the shard (if relocation target).
*
* - If shard is a primary, this also fails initializing replicas.
* - If shard is an active primary, this also promotes an active replica to primary (if such a replica exists).
* - If shard is a relocating primary, this also removes the primary relocation target shard.
* - If shard is a relocating replica, this promotes the replica relocation target to a full initializing replica, removing the
* relocation source information. This is possible as peer recovery is always done from the primary.
* - If shard is a (primary or replica) relocation target, this also clears the relocation information on the source shard.
*
*/
public void failShard(Logger logger, ShardRouting failedShard, UnassignedInfo unassignedInfo, IndexMetadata indexMetadata,
RoutingChangesObserver routingChangesObserver) {
ensureMutable();
assert failedShard.assignedToNode() : "only assigned shards can be failed";
assert indexMetadata.getIndex().equals(failedShard.index()) :
"shard failed for unknown index (shard entry: " + failedShard + ")";
assert getByAllocationId(failedShard.shardId(), failedShard.allocationId().getId()) == failedShard :
"shard routing to fail does not exist in routing table, expected: " + failedShard + " but was: " +
getByAllocationId(failedShard.shardId(), failedShard.allocationId().getId());
logger.debug("{} failing shard {} with unassigned info ({})", failedShard.shardId(), failedShard, unassignedInfo.shortSummary());
// if this is a primary, fail initializing replicas first (otherwise we move RoutingNodes into an inconsistent state)
if (failedShard.primary()) {
List<ShardRouting> assignedShards = assignedShards(failedShard.shardId());
if (assignedShards.isEmpty() == false) {
// copy list to prevent ConcurrentModificationException
for (ShardRouting routing : new ArrayList<>(assignedShards)) {
if (routing.primary() == false && routing.initializing()) {
// re-resolve replica as earlier iteration could have changed source/target of replica relocation
ShardRouting replicaShard = getByAllocationId(routing.shardId(), routing.allocationId().getId());
assert replicaShard != null : "failed to re-resolve " + routing + " when failing replicas";
UnassignedInfo primaryFailedUnassignedInfo = new UnassignedInfo(UnassignedInfo.Reason.PRIMARY_FAILED,
"primary failed while replica initializing", null, 0, unassignedInfo.getUnassignedTimeInNanos(),
unassignedInfo.getUnassignedTimeInMillis(), false, AllocationStatus.NO_ATTEMPT, Collections.emptySet());
failShard(logger, replicaShard, primaryFailedUnassignedInfo, indexMetadata, routingChangesObserver);
}
}
}
}
if (failedShard.relocating()) {
// find the shard that is initializing on the target node
ShardRouting targetShard = getByAllocationId(failedShard.shardId(), failedShard.allocationId().getRelocationId());
assert targetShard.isRelocationTargetOf(failedShard);
if (failedShard.primary()) {
logger.trace("{} is removed due to the failure/cancellation of the source shard", targetShard);
// cancel and remove target shard
remove(targetShard);
routingChangesObserver.shardFailed(targetShard, unassignedInfo);
} else {
logger.trace("{}, relocation source failed / cancelled, mark as initializing without relocation source", targetShard);
// promote to initializing shard without relocation source and ensure that removed relocation source
// is not added back as unassigned shard
removeRelocationSource(targetShard);
routingChangesObserver.relocationSourceRemoved(targetShard);
}
}
// fail actual shard
if (failedShard.initializing()) {
if (failedShard.relocatingNodeId() == null) {
if (failedShard.primary()) {
// promote active replica to primary if active replica exists (only the case for shadow replicas)
unassignPrimaryAndPromoteActiveReplicaIfExists(failedShard, unassignedInfo, routingChangesObserver);
} else {
// initializing shard that is not relocation target, just move to unassigned
moveToUnassigned(failedShard, unassignedInfo);
}
} else {
// The shard is a target of a relocating shard. In that case we only need to remove the target shard and cancel the source
// relocation. No shard is left unassigned
logger.trace("{} is a relocation target, resolving source to cancel relocation ({})", failedShard,
unassignedInfo.shortSummary());
ShardRouting sourceShard = getByAllocationId(failedShard.shardId(),
failedShard.allocationId().getRelocationId());
assert sourceShard.isRelocationSourceOf(failedShard);
logger.trace("{}, resolved source to [{}]. canceling relocation ... ({})", failedShard.shardId(), sourceShard,
unassignedInfo.shortSummary());
cancelRelocation(sourceShard);
remove(failedShard);
}
} else {
assert failedShard.active();
if (failedShard.primary()) {
// promote active replica to primary if active replica exists
unassignPrimaryAndPromoteActiveReplicaIfExists(failedShard, unassignedInfo, routingChangesObserver);
} else {
if (failedShard.relocating()) {
remove(failedShard);
} else {
moveToUnassigned(failedShard, unassignedInfo);
}
}
}
routingChangesObserver.shardFailed(failedShard, unassignedInfo);
assert node(failedShard.currentNodeId()).getByShardId(failedShard.shardId()) == null : "failedShard " + failedShard +
" was matched but wasn't removed";
}
private void unassignPrimaryAndPromoteActiveReplicaIfExists(ShardRouting failedShard, UnassignedInfo unassignedInfo,
RoutingChangesObserver routingChangesObserver) {
assert failedShard.primary();
ShardRouting activeReplica = activeReplicaWithHighestVersion(failedShard.shardId());
if (activeReplica == null) {
moveToUnassigned(failedShard, unassignedInfo);
} else {
movePrimaryToUnassignedAndDemoteToReplica(failedShard, unassignedInfo);
promoteReplicaToPrimary(activeReplica, routingChangesObserver);
}
}
private void promoteReplicaToPrimary(ShardRouting activeReplica, RoutingChangesObserver routingChangesObserver) {
// if the activeReplica was relocating before this call to failShard, its relocation was cancelled earlier when we
// failed initializing replica shards (and moved replica relocation source back to started)
assert activeReplica.started() : "replica relocation should have been cancelled: " + activeReplica;
promoteActiveReplicaShardToPrimary(activeReplica);
routingChangesObserver.replicaPromoted(activeReplica);
}
/**
* Mark a shard as started and adjusts internal statistics.
*
* @return the started shard
*/
private ShardRouting started(ShardRouting shard) {
assert shard.initializing() : "expected an initializing shard " + shard;
if (shard.relocatingNodeId() == null) {
// if this is not a target shard for relocation, we need to update statistics
inactiveShardCount--;
if (shard.primary()) {
inactivePrimaryCount--;
}
}
removeRecovery(shard);
ShardRouting startedShard = shard.moveToStarted();
updateAssigned(shard, startedShard);
return startedShard;
}
/**
* Cancels a relocation of a shard that shard must relocating.
*
* @return the shard after cancelling relocation
*/
private ShardRouting cancelRelocation(ShardRouting shard) {
relocatingShards--;
ShardRouting cancelledShard = shard.cancelRelocation();
updateAssigned(shard, cancelledShard);
return cancelledShard;
}
/**
* moves the assigned replica shard to primary.
*
* @param replicaShard the replica shard to be promoted to primary
* @return the resulting primary shard
*/
private ShardRouting promoteActiveReplicaShardToPrimary(ShardRouting replicaShard) {
assert replicaShard.active() : "non-active shard cannot be promoted to primary: " + replicaShard;
assert replicaShard.primary() == false : "primary shard cannot be promoted to primary: " + replicaShard;
ShardRouting primaryShard = replicaShard.moveActiveReplicaToPrimary();
updateAssigned(replicaShard, primaryShard);
return primaryShard;
}
private static final List<ShardRouting> EMPTY = Collections.emptyList();
/**
* Cancels the give shard from the Routing nodes internal statistics and cancels
* the relocation if the shard is relocating.
*/
private void remove(ShardRouting shard) {
assert shard.unassigned() == false : "only assigned shards can be removed here (" + shard + ")";
node(shard.currentNodeId()).remove(shard);
if (shard.initializing() && shard.relocatingNodeId() == null) {
inactiveShardCount--;
assert inactiveShardCount >= 0;
if (shard.primary()) {
inactivePrimaryCount--;
}
} else if (shard.relocating()) {
shard = cancelRelocation(shard);
}
assignedShardsRemove(shard);
if (shard.initializing()) {
removeRecovery(shard);
}
}
/**
* Removes relocation source of an initializing non-primary shard. This allows the replica shard to continue recovery from
* the primary even though its non-primary relocation source has failed.
*/
private ShardRouting removeRelocationSource(ShardRouting shard) {
assert shard.isRelocationTarget() : "only relocation target shards can have their relocation source removed (" + shard + ")";
ShardRouting relocationMarkerRemoved = shard.removeRelocationSource();
updateAssigned(shard, relocationMarkerRemoved);
inactiveShardCount++; // relocation targets are not counted as inactive shards whereas initializing shards are
return relocationMarkerRemoved;
}
private void assignedShardsAdd(ShardRouting shard) {
assert shard.unassigned() == false : "unassigned shard " + shard + " cannot be added to list of assigned shards";
List<ShardRouting> shards = assignedShards.computeIfAbsent(shard.shardId(), k -> new ArrayList<>());
assert assertInstanceNotInList(shard, shards) : "shard " + shard + " cannot appear twice in list of assigned shards";
shards.add(shard);
}
private boolean assertInstanceNotInList(ShardRouting shard, List<ShardRouting> shards) {
for (ShardRouting s : shards) {
assert s != shard;
}
return true;
}
private void assignedShardsRemove(ShardRouting shard) {
final List<ShardRouting> replicaSet = assignedShards.get(shard.shardId());
if (replicaSet != null) {
final Iterator<ShardRouting> iterator = replicaSet.iterator();
while(iterator.hasNext()) {
// yes we check identity here
if (shard == iterator.next()) {
iterator.remove();
return;
}
}
}
assert false : "No shard found to remove";
}
private ShardRouting reinitReplica(ShardRouting shard) {
assert shard.primary() == false : "shard must be a replica: " + shard;
assert shard.initializing() : "can only reinitialize an initializing replica: " + shard;
assert shard.isRelocationTarget() == false : "replication target cannot be reinitialized: " + shard;
ShardRouting reinitializedShard = shard.reinitializeReplicaShard();
updateAssigned(shard, reinitializedShard);
return reinitializedShard;
}
private void updateAssigned(ShardRouting oldShard, ShardRouting newShard) {
assert oldShard.shardId().equals(newShard.shardId()) :
"can only update " + oldShard + " by shard with same shard id but was " + newShard;
assert oldShard.unassigned() == false && newShard.unassigned() == false :
"only assigned shards can be updated in list of assigned shards (prev: " + oldShard + ", new: " + newShard + ")";
assert oldShard.currentNodeId().equals(newShard.currentNodeId()) : "shard to update " + oldShard +
" can only update " + oldShard + " by shard assigned to same node but was " + newShard;
node(oldShard.currentNodeId()).update(oldShard, newShard);
List<ShardRouting> shardsWithMatchingShardId = assignedShards.computeIfAbsent(oldShard.shardId(), k -> new ArrayList<>());
int previousShardIndex = shardsWithMatchingShardId.indexOf(oldShard);
assert previousShardIndex >= 0 : "shard to update " + oldShard + " does not exist in list of assigned shards";
shardsWithMatchingShardId.set(previousShardIndex, newShard);
}
private ShardRouting moveToUnassigned(ShardRouting shard, UnassignedInfo unassignedInfo) {
assert shard.unassigned() == false : "only assigned shards can be moved to unassigned (" + shard + ")";
remove(shard);
ShardRouting unassigned = shard.moveToUnassigned(unassignedInfo);
unassignedShards.add(unassigned);
return unassigned;
}
/**
* Moves assigned primary to unassigned and demotes it to a replica.
* Used in conjunction with {@link #promoteActiveReplicaShardToPrimary} when an active replica is promoted to primary.
*/
private ShardRouting movePrimaryToUnassignedAndDemoteToReplica(ShardRouting shard, UnassignedInfo unassignedInfo) {
assert shard.unassigned() == false : "only assigned shards can be moved to unassigned (" + shard + ")";
assert shard.primary() : "only primary can be demoted to replica (" + shard + ")";
remove(shard);
ShardRouting unassigned = shard.moveToUnassigned(unassignedInfo).moveUnassignedFromPrimary();
unassignedShards.add(unassigned);
return unassigned;
}
/**
* Returns the number of routing nodes
*/
public int size() {
return nodesToShards.size();
}
public static final class UnassignedShards implements Iterable<ShardRouting> {
private final RoutingNodes nodes;
private final List<ShardRouting> unassigned;
private final List<ShardRouting> ignored;
private int primaries = 0;
private int ignoredPrimaries = 0;
public UnassignedShards(RoutingNodes nodes) {
this.nodes = nodes;
unassigned = new ArrayList<>();
ignored = new ArrayList<>();
}
public void add(ShardRouting shardRouting) {
if(shardRouting.primary()) {
primaries++;
}
unassigned.add(shardRouting);
}
public void sort(Comparator<ShardRouting> comparator) {
nodes.ensureMutable();
CollectionUtil.timSort(unassigned, comparator);
}
/**
* Returns the size of the non-ignored unassigned shards
*/
public int size() { return unassigned.size(); }
/**
* Returns the number of non-ignored unassigned primaries
*/
public int getNumPrimaries() {
return primaries;
}
/**
* Returns the number of temporarily marked as ignored unassigned primaries
*/
public int getNumIgnoredPrimaries() { return ignoredPrimaries; }
@Override
public UnassignedIterator iterator() {
return new UnassignedIterator();
}
/**
* The list of ignored unassigned shards (read only). The ignored unassigned shards
* are not part of the formal unassigned list, but are kept around and used to build
* back the list of unassigned shards as part of the routing table.
*/
public List<ShardRouting> ignored() {
return Collections.unmodifiableList(ignored);
}
/**
* Marks a shard as temporarily ignored and adds it to the ignore unassigned list.
* Should be used with caution, typically,
* the correct usage is to removeAndIgnore from the iterator.
* @see #ignored()
* @see UnassignedIterator#removeAndIgnore(AllocationStatus, RoutingChangesObserver)
* @see #isIgnoredEmpty()
*/
public void ignoreShard(ShardRouting shard, AllocationStatus allocationStatus, RoutingChangesObserver changes) {
nodes.ensureMutable();
if (shard.primary()) {
ignoredPrimaries++;
UnassignedInfo currInfo = shard.unassignedInfo();
assert currInfo != null;
if (allocationStatus.equals(currInfo.getLastAllocationStatus()) == false) {
UnassignedInfo newInfo = new UnassignedInfo(currInfo.getReason(), currInfo.getMessage(), currInfo.getFailure(),
currInfo.getNumFailedAllocations(), currInfo.getUnassignedTimeInNanos(),
currInfo.getUnassignedTimeInMillis(), currInfo.isDelayed(),
allocationStatus, currInfo.getFailedNodeIds());
ShardRouting updatedShard = shard.updateUnassigned(newInfo, shard.recoverySource());
changes.unassignedInfoUpdated(shard, newInfo);
shard = updatedShard;
}
}
ignored.add(shard);
}
public class UnassignedIterator implements Iterator<ShardRouting>, ExistingShardsAllocator.UnassignedAllocationHandler {
private final ListIterator<ShardRouting> iterator;
private ShardRouting current;
public UnassignedIterator() {
this.iterator = unassigned.listIterator();
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public ShardRouting next() {
return current = iterator.next();
}
/**
* Initializes the current unassigned shard and moves it from the unassigned list.
*
* @param existingAllocationId allocation id to use. If null, a fresh allocation id is generated.
*/
@Override
public ShardRouting initialize(String nodeId, @Nullable String existingAllocationId, long expectedShardSize,
RoutingChangesObserver routingChangesObserver) {
nodes.ensureMutable();
innerRemove();
return nodes.initializeShard(current, nodeId, existingAllocationId, expectedShardSize, routingChangesObserver);
}
/**
* Removes and ignores the unassigned shard (will be ignored for this run, but
* will be added back to unassigned once the metadata is constructed again).
* Typically this is used when an allocation decision prevents a shard from being allocated such
* that subsequent consumers of this API won't try to allocate this shard again.
*
* @param attempt the result of the allocation attempt
*/
@Override
public void removeAndIgnore(AllocationStatus attempt, RoutingChangesObserver changes) {
nodes.ensureMutable();
innerRemove();
ignoreShard(current, attempt, changes);
}
private void updateShardRouting(ShardRouting shardRouting) {
current = shardRouting;
iterator.set(shardRouting);
}
/**
* updates the unassigned info and recovery source on the current unassigned shard
*
* @param unassignedInfo the new unassigned info to use
* @param recoverySource the new recovery source to use
* @return the shard with unassigned info updated
*/
@Override
public ShardRouting updateUnassigned(UnassignedInfo unassignedInfo, RecoverySource recoverySource,
RoutingChangesObserver changes) {
nodes.ensureMutable();
ShardRouting updatedShardRouting = current.updateUnassigned(unassignedInfo, recoverySource);
changes.unassignedInfoUpdated(current, unassignedInfo);
updateShardRouting(updatedShardRouting);
return updatedShardRouting;
}
/**
* Unsupported operation, just there for the interface. Use
* {@link #removeAndIgnore(AllocationStatus, RoutingChangesObserver)} or
* {@link #initialize(String, String, long, RoutingChangesObserver)}.
*/
@Override
public void remove() {
throw new UnsupportedOperationException("remove is not supported in unassigned iterator," +
" use removeAndIgnore or initialize");
}
private void innerRemove() {
iterator.remove();
if (current.primary()) {
primaries--;
}
}
}
/**
* Returns <code>true</code> iff this collection contains one or more non-ignored unassigned shards.
*/
public boolean isEmpty() {
return unassigned.isEmpty();
}
/**
* Returns <code>true</code> iff any unassigned shards are marked as temporarily ignored.
* @see UnassignedShards#ignoreShard(ShardRouting, AllocationStatus, RoutingChangesObserver)
* @see UnassignedIterator#removeAndIgnore(AllocationStatus, RoutingChangesObserver)
*/
public boolean isIgnoredEmpty() {
return ignored.isEmpty();
}
public void shuffle() {
nodes.ensureMutable();
Randomness.shuffle(unassigned);
}
/**
* Drains all unassigned shards and returns it.
* This method will not drain ignored shards.
*/
public ShardRouting[] drain() {
nodes.ensureMutable();
ShardRouting[] mutableShardRoutings = unassigned.toArray(new ShardRouting[unassigned.size()]);
unassigned.clear();
primaries = 0;
return mutableShardRoutings;
}
}