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Elasticsearch - Open Source, Distributed, RESTful Search Engine
/*
* 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.gateway;
import com.google.common.collect.ImmutableSet;
import org.elasticsearch.Version;
import org.elasticsearch.cluster.ClusterChangedEvent;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateListener;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.cluster.metadata.MetaDataIndexUpgradeService;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.RoutingNode;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.util.MultiDataPathUpgrader;
import org.elasticsearch.env.NodeEnvironment;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
*
*/
public class GatewayMetaState extends AbstractComponent implements ClusterStateListener {
private final NodeEnvironment nodeEnv;
private final MetaStateService metaStateService;
private final DanglingIndicesState danglingIndicesState;
private final MetaDataIndexUpgradeService metaDataIndexUpgradeService;
@Nullable
private volatile MetaData previousMetaData;
private volatile ImmutableSet previouslyWrittenIndices = ImmutableSet.of();
@Inject
public GatewayMetaState(Settings settings, NodeEnvironment nodeEnv, MetaStateService metaStateService,
DanglingIndicesState danglingIndicesState, TransportNodesListGatewayMetaState nodesListGatewayMetaState,
MetaDataIndexUpgradeService metaDataIndexUpgradeService) throws Exception {
super(settings);
this.nodeEnv = nodeEnv;
this.metaStateService = metaStateService;
this.danglingIndicesState = danglingIndicesState;
this.metaDataIndexUpgradeService = metaDataIndexUpgradeService;
nodesListGatewayMetaState.init(this);
if (DiscoveryNode.dataNode(settings)) {
ensureNoPre019ShardState(nodeEnv);
MultiDataPathUpgrader.upgradeMultiDataPath(nodeEnv, logger);
}
if (DiscoveryNode.masterNode(settings) || DiscoveryNode.dataNode(settings)) {
nodeEnv.ensureAtomicMoveSupported();
}
if (DiscoveryNode.masterNode(settings) || DiscoveryNode.dataNode(settings)) {
try {
ensureNoPre019State();
pre20Upgrade();
long startNS = System.nanoTime();
metaStateService.loadFullState();
logger.debug("took {} to load state", TimeValue.timeValueMillis(TimeValue.nsecToMSec(System.nanoTime() - startNS)));
} catch (Exception e) {
logger.error("failed to read local state, exiting...", e);
throw e;
}
}
}
public MetaData loadMetaState() throws Exception {
return metaStateService.loadFullState();
}
@Override
public void clusterChanged(ClusterChangedEvent event) {
Set relevantIndices = new HashSet<>();
final ClusterState state = event.state();
if (state.blocks().disableStatePersistence()) {
// reset the current metadata, we need to start fresh...
this.previousMetaData = null;
previouslyWrittenIndices = ImmutableSet.of();
return;
}
MetaData newMetaData = state.metaData();
// we don't check if metaData changed, since we might be called several times and we need to check dangling...
boolean success = true;
// write the state if this node is a master eligible node or if it is a data node and has shards allocated on it
if (state.nodes().localNode().masterNode() || state.nodes().localNode().dataNode()) {
if (previousMetaData == null) {
try {
// we determine if or if not we write meta data on data only nodes by looking at the shard routing
// and only write if a shard of this index is allocated on this node
// however, closed indices do not appear in the shard routing. if the meta data for a closed index is
// updated it will therefore not be written in case the list of previouslyWrittenIndices is empty (because state
// persistence was disabled or the node was restarted), see getRelevantIndicesOnDataOnlyNode().
// we therefore have to check here if we have shards on disk and add their indices to the previouslyWrittenIndices list
if (isDataOnlyNode(state)) {
ImmutableSet.Builder previouslyWrittenIndicesBuilder = ImmutableSet.builder();
for (IndexMetaData indexMetaData : newMetaData) {
IndexMetaData indexMetaDataOnDisk = null;
if (indexMetaData.getState().equals(IndexMetaData.State.CLOSE)) {
indexMetaDataOnDisk = metaStateService.loadIndexState(indexMetaData.getIndex());
}
if (indexMetaDataOnDisk != null) {
previouslyWrittenIndicesBuilder.add(indexMetaDataOnDisk.getIndex());
}
}
previouslyWrittenIndices = previouslyWrittenIndicesBuilder.addAll(previouslyWrittenIndices).build();
}
} catch (Throwable e) {
success = false;
}
}
// check if the global state changed?
if (previousMetaData == null || !MetaData.isGlobalStateEquals(previousMetaData, newMetaData)) {
try {
metaStateService.writeGlobalState("changed", newMetaData);
} catch (Throwable e) {
success = false;
}
}
Iterable writeInfo;
relevantIndices = getRelevantIndices(event.state(), event.previousState(), previouslyWrittenIndices);
writeInfo = resolveStatesToBeWritten(previouslyWrittenIndices, relevantIndices, previousMetaData, event.state().metaData());
// check and write changes in indices
for (IndexMetaWriteInfo indexMetaWrite : writeInfo) {
try {
metaStateService.writeIndex(indexMetaWrite.reason, indexMetaWrite.newMetaData, indexMetaWrite.previousMetaData);
} catch (Throwable e) {
success = false;
}
}
}
danglingIndicesState.processDanglingIndices(newMetaData);
if (success) {
previousMetaData = newMetaData;
ImmutableSet.Builder builder = ImmutableSet.builder();
previouslyWrittenIndices = builder.addAll(relevantIndices).build();
}
}
public static Set getRelevantIndices(ClusterState state, ClusterState previousState,ImmutableSet previouslyWrittenIndices) {
Set relevantIndices;
if (isDataOnlyNode(state)) {
relevantIndices = getRelevantIndicesOnDataOnlyNode(state, previousState, previouslyWrittenIndices);
} else if (state.nodes().localNode().masterNode() == true) {
relevantIndices = getRelevantIndicesForMasterEligibleNode(state);
} else {
relevantIndices = Collections.emptySet();
}
return relevantIndices;
}
protected static boolean isDataOnlyNode(ClusterState state) {
return ((state.nodes().localNode().masterNode() == false) && state.nodes().localNode().dataNode());
}
/**
* Throws an IAE if a pre 0.19 state is detected
*/
private void ensureNoPre019State() throws Exception {
for (Path dataLocation : nodeEnv.nodeDataPaths()) {
final Path stateLocation = dataLocation.resolve(MetaDataStateFormat.STATE_DIR_NAME);
if (!Files.exists(stateLocation)) {
continue;
}
try (DirectoryStream stream = Files.newDirectoryStream(stateLocation)) {
for (Path stateFile : stream) {
if (logger.isTraceEnabled()) {
logger.trace("[upgrade]: processing [" + stateFile.getFileName() + "]");
}
final String name = stateFile.getFileName().toString();
if (name.startsWith("metadata-")) {
throw new IllegalStateException("Detected pre 0.19 metadata file please upgrade to a version before "
+ Version.CURRENT.minimumCompatibilityVersion()
+ " first to upgrade state structures - metadata found: [" + stateFile.getParent().toAbsolutePath());
}
}
}
}
}
/**
* Elasticsearch 2.0 removed several deprecated features and as well as support for Lucene 3.x. This method calls
* {@link MetaDataIndexUpgradeService} to makes sure that indices are compatible with the current version. The
* MetaDataIndexUpgradeService might also update obsolete settings if needed. When this happens we rewrite
* index metadata with new settings.
*/
private void pre20Upgrade() throws Exception {
MetaData metaData = loadMetaState();
List updateIndexMetaData = new ArrayList<>();
for (IndexMetaData indexMetaData : metaData) {
IndexMetaData newMetaData = metaDataIndexUpgradeService.upgradeIndexMetaData(indexMetaData);
if (indexMetaData != newMetaData) {
updateIndexMetaData.add(newMetaData);
}
}
// We successfully checked all indices for backward compatibility and found no non-upgradable indices, which
// means the upgrade can continue. Now it's safe to overwrite index metadata with the new version.
for (IndexMetaData indexMetaData : updateIndexMetaData) {
metaStateService.writeIndex("upgrade", indexMetaData, null);
}
}
// shard state BWC
private void ensureNoPre019ShardState(NodeEnvironment nodeEnv) throws Exception {
for (Path dataLocation : nodeEnv.nodeDataPaths()) {
final Path stateLocation = dataLocation.resolve(MetaDataStateFormat.STATE_DIR_NAME);
if (Files.exists(stateLocation)) {
try (DirectoryStream stream = Files.newDirectoryStream(stateLocation, "shards-*")) {
for (Path stateFile : stream) {
throw new IllegalStateException("Detected pre 0.19 shard state file please upgrade to a version before "
+ Version.CURRENT.minimumCompatibilityVersion()
+ " first to upgrade state structures - shard state found: [" + stateFile.getParent().toAbsolutePath());
}
}
}
}
}
/**
* Loads the current meta state for each index in the new cluster state and checks if it has to be persisted.
* Each index state that should be written to disk will be returned. This is only run for data only nodes.
* It will return only the states for indices that actually have a shard allocated on the current node.
*
* @param previouslyWrittenIndices A list of indices for which the state was already written before
* @param potentiallyUnwrittenIndices The list of indices for which state should potentially be written
* @param previousMetaData The last meta data we know of. meta data for all indices in previouslyWrittenIndices list is persisted now
* @param newMetaData The new metadata
* @return iterable over all indices states that should be written to disk
*/
public static Iterable resolveStatesToBeWritten(ImmutableSet previouslyWrittenIndices, Set potentiallyUnwrittenIndices, MetaData previousMetaData, MetaData newMetaData) {
List indicesToWrite = new ArrayList<>();
for (String index : potentiallyUnwrittenIndices) {
IndexMetaData newIndexMetaData = newMetaData.index(index);
IndexMetaData previousIndexMetaData = previousMetaData == null ? null : previousMetaData.index(index);
String writeReason = null;
if (previouslyWrittenIndices.contains(index) == false || previousIndexMetaData == null) {
writeReason = "freshly created";
} else if (previousIndexMetaData.getVersion() != newIndexMetaData.getVersion()) {
writeReason = "version changed from [" + previousIndexMetaData.getVersion() + "] to [" + newIndexMetaData.getVersion() + "]";
}
if (writeReason != null) {
indicesToWrite.add(new GatewayMetaState.IndexMetaWriteInfo(newIndexMetaData, previousIndexMetaData, writeReason));
}
}
return indicesToWrite;
}
public static Set getRelevantIndicesOnDataOnlyNode(ClusterState state, ClusterState previousState, ImmutableSet previouslyWrittenIndices) {
RoutingNode newRoutingNode = state.getRoutingNodes().node(state.nodes().localNodeId());
if (newRoutingNode == null) {
throw new IllegalStateException("cluster state does not contain this node - cannot write index meta state");
}
Set indices = new HashSet<>();
for (ShardRouting routing : newRoutingNode) {
indices.add(routing.index());
}
// we have to check the meta data also: closed indices will not appear in the routing table, but we must still write the state if we have it written on disk previously
for (IndexMetaData indexMetaData : state.metaData()) {
boolean isOrWasClosed = indexMetaData.getState().equals(IndexMetaData.State.CLOSE);
// if the index is open we might still have to write the state if it just transitioned from closed to open
// so we have to check for that as well.
IndexMetaData previousMetaData = previousState.metaData().getIndices().get(indexMetaData.getIndex());
if (previousMetaData != null) {
isOrWasClosed = isOrWasClosed || previousMetaData.getState().equals(IndexMetaData.State.CLOSE);
}
if (previouslyWrittenIndices.contains(indexMetaData.getIndex()) && isOrWasClosed) {
indices.add(indexMetaData.getIndex());
}
}
return indices;
}
public static Set getRelevantIndicesForMasterEligibleNode(ClusterState state) {
Set relevantIndices;
relevantIndices = new HashSet<>();
// we have to iterate over the metadata to make sure we also capture closed indices
for (IndexMetaData indexMetaData : state.metaData()) {
relevantIndices.add(indexMetaData.getIndex());
}
return relevantIndices;
}
public static class IndexMetaWriteInfo {
final IndexMetaData newMetaData;
final String reason;
final IndexMetaData previousMetaData;
public IndexMetaWriteInfo(IndexMetaData newMetaData, IndexMetaData previousMetaData, String reason) {
this.newMetaData = newMetaData;
this.reason = reason;
this.previousMetaData = previousMetaData;
}
public IndexMetaData getNewMetaData() {
return newMetaData;
}
public String getReason() {
return reason;
}
}
}