org.elasticsearch.gateway.MetaStateService Maven / Gradle / Ivy
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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.gateway;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.Version;
import org.elasticsearch.cluster.metadata.IndexGraveyard;
import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.cluster.metadata.Manifest;
import org.elasticsearch.cluster.metadata.Metadata;
import org.elasticsearch.core.Nullable;
import org.elasticsearch.core.Tuple;
import org.elasticsearch.env.NodeEnvironment;
import org.elasticsearch.index.Index;
import org.elasticsearch.xcontent.NamedXContentRegistry;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.Predicate;
/**
* Handles writing and loading {@link Manifest}, {@link Metadata} and {@link IndexMetadata}
*/
public class MetaStateService {
private static final Logger logger = LogManager.getLogger(MetaStateService.class);
private final NodeEnvironment nodeEnv;
private final NamedXContentRegistry namedXContentRegistry;
// we allow subclasses in tests to redefine formats, e.g. to inject failures
protected MetadataStateFormat METADATA_FORMAT = Metadata.FORMAT;
protected MetadataStateFormat INDEX_METADATA_FORMAT = IndexMetadata.FORMAT;
protected MetadataStateFormat MANIFEST_FORMAT = Manifest.FORMAT;
public MetaStateService(NodeEnvironment nodeEnv, NamedXContentRegistry namedXContentRegistry) {
this.nodeEnv = nodeEnv;
this.namedXContentRegistry = namedXContentRegistry;
}
/**
* Loads the full state, which includes both the global state and all the indices meta data.
* When loading, manifest file is consulted (represented by {@link Manifest} class), to load proper generations.
* If there is no manifest file on disk, this method fallbacks to BWC mode, where latest generation of global and indices
* metadata is loaded. Please note that currently there is no way to distinguish between manifest file being removed and manifest
* file was not yet created. It means that this method always fallbacks to BWC mode, if there is no manifest file.
*
* @return tuple of {@link Manifest} and {@link Metadata} with global metadata and indices metadata. If there is no state on disk,
* meta state with globalGeneration -1 and empty meta data is returned.
* @throws IOException if some IOException when loading files occurs or there is no metadata referenced by manifest file.
*/
public Tuple loadFullState() throws IOException {
final Manifest manifest = MANIFEST_FORMAT.loadLatestState(logger, namedXContentRegistry, nodeEnv.nodeDataPaths());
if (manifest == null) {
return loadFullStateBWC();
}
final Metadata.Builder metadataBuilder;
if (manifest.isGlobalGenerationMissing()) {
metadataBuilder = Metadata.builder();
} else {
final Metadata globalMetadata = METADATA_FORMAT.loadGeneration(
logger,
namedXContentRegistry,
manifest.getGlobalGeneration(),
nodeEnv.nodeDataPaths()
);
if (globalMetadata != null) {
metadataBuilder = Metadata.builder(globalMetadata);
} else {
throw new IOException("failed to find global metadata [generation: " + manifest.getGlobalGeneration() + "]");
}
}
for (Map.Entry entry : manifest.getIndexGenerations().entrySet()) {
final Index index = entry.getKey();
final long generation = entry.getValue();
final String indexFolderName = index.getUUID();
final IndexMetadata indexMetadata = INDEX_METADATA_FORMAT.loadGeneration(
logger,
namedXContentRegistry,
generation,
nodeEnv.resolveIndexFolder(indexFolderName)
);
if (indexMetadata != null) {
metadataBuilder.put(indexMetadata, false);
} else {
throw new IOException(
"failed to find metadata for existing index "
+ index.getName()
+ " [location: "
+ indexFolderName
+ ", generation: "
+ generation
+ "]"
);
}
}
return new Tuple<>(manifest, metadataBuilder.build());
}
/**
* "Manifest-less" BWC version of loading metadata from disk. See also {@link #loadFullState()}
*/
private Tuple loadFullStateBWC() throws IOException {
Map indices = new HashMap<>();
Metadata.Builder metadataBuilder;
Tuple metadataAndGeneration = METADATA_FORMAT.loadLatestStateWithGeneration(
logger,
namedXContentRegistry,
nodeEnv.nodeDataPaths()
);
Metadata globalMetadata = metadataAndGeneration.v1();
long globalStateGeneration = metadataAndGeneration.v2();
final IndexGraveyard indexGraveyard;
if (globalMetadata != null) {
metadataBuilder = Metadata.builder(globalMetadata);
indexGraveyard = globalMetadata.custom(IndexGraveyard.TYPE);
assert Version.CURRENT.major < 8 : "failed to find manifest file, which is mandatory staring with Elasticsearch version 8.0";
} else {
metadataBuilder = Metadata.builder();
indexGraveyard = IndexGraveyard.builder().build();
}
for (String indexFolderName : nodeEnv.availableIndexFolders()) {
Tuple indexMetadataAndGeneration = INDEX_METADATA_FORMAT.loadLatestStateWithGeneration(
logger,
namedXContentRegistry,
nodeEnv.resolveIndexFolder(indexFolderName)
);
assert Version.CURRENT.major < 8 : "failed to find manifest file, which is mandatory staring with Elasticsearch version 8.0";
IndexMetadata indexMetadata = indexMetadataAndGeneration.v1();
long generation = indexMetadataAndGeneration.v2();
if (indexMetadata != null) {
if (indexGraveyard.containsIndex(indexMetadata.getIndex())) {
logger.debug("[{}] found metadata for deleted index [{}]", indexFolderName, indexMetadata.getIndex());
// this index folder is cleared up when state is recovered
} else {
indices.put(indexMetadata.getIndex(), generation);
metadataBuilder.put(indexMetadata, false);
}
} else {
logger.debug("[{}] failed to find metadata for existing index location", indexFolderName);
}
}
Manifest manifest = Manifest.unknownCurrentTermAndVersion(globalStateGeneration, indices);
return new Tuple<>(manifest, metadataBuilder.build());
}
/**
* Loads the index state for the provided index name, returning null if doesn't exists.
*/
@Nullable
public IndexMetadata loadIndexState(Index index) throws IOException {
return INDEX_METADATA_FORMAT.loadLatestState(logger, namedXContentRegistry, nodeEnv.indexPaths(index));
}
/**
* Loads all indices states available on disk
*/
List loadIndicesStates(Predicate excludeIndexPathIdsPredicate) throws IOException {
List indexMetadataList = new ArrayList<>();
for (String indexFolderName : nodeEnv.availableIndexFolders(excludeIndexPathIdsPredicate)) {
assert excludeIndexPathIdsPredicate.test(indexFolderName) == false
: "unexpected folder " + indexFolderName + " which should have been excluded";
IndexMetadata indexMetadata = INDEX_METADATA_FORMAT.loadLatestState(
logger,
namedXContentRegistry,
nodeEnv.resolveIndexFolder(indexFolderName)
);
if (indexMetadata != null) {
final String indexPathId = indexMetadata.getIndex().getUUID();
if (indexFolderName.equals(indexPathId)) {
indexMetadataList.add(indexMetadata);
} else {
throw new IllegalStateException("[" + indexFolderName + "] invalid index folder name, rename to [" + indexPathId + "]");
}
} else {
logger.debug("[{}] failed to find metadata for existing index location", indexFolderName);
}
}
return indexMetadataList;
}
/**
* Loads Manifest file from disk, returns Manifest.empty() if there is no manifest file.
*/
public Manifest loadManifestOrEmpty() throws IOException {
Manifest manifest = MANIFEST_FORMAT.loadLatestState(logger, namedXContentRegistry, nodeEnv.nodeDataPaths());
if (manifest == null) {
manifest = Manifest.empty();
}
return manifest;
}
/**
* Loads the global state, *without* index state, see {@link #loadFullState()} for that.
*/
Metadata loadGlobalState() throws IOException {
return METADATA_FORMAT.loadLatestState(logger, namedXContentRegistry, nodeEnv.nodeDataPaths());
}
/**
* Writes manifest file (represented by {@link Manifest}) to disk and performs cleanup of old manifest state file if
* the write succeeds or newly created manifest state if the write fails.
*
* @throws WriteStateException if exception when writing state occurs. See also {@link WriteStateException#isDirty()}
*/
public void writeManifestAndCleanup(String reason, Manifest manifest) throws WriteStateException {
logger.trace("[_meta] writing state, reason [{}]", reason);
try {
long generation = MANIFEST_FORMAT.writeAndCleanup(manifest, nodeEnv.nodeDataPaths());
logger.trace("[_meta] state written (generation: {})", generation);
} catch (WriteStateException ex) {
throw new WriteStateException(ex.isDirty(), "[_meta]: failed to write meta state", ex);
}
}
/**
* Writes the index state.
*
* This method is public for testing purposes.
*
* @throws WriteStateException if exception when writing state occurs. {@link WriteStateException#isDirty()} will always return
* false, because new index state file is not yet referenced by manifest file.
*/
public long writeIndex(String reason, IndexMetadata indexMetadata) throws WriteStateException {
final Index index = indexMetadata.getIndex();
logger.trace("[{}] writing state, reason [{}]", index, reason);
try {
long generation = INDEX_METADATA_FORMAT.write(indexMetadata, nodeEnv.indexPaths(indexMetadata.getIndex()));
logger.trace("[{}] state written", index);
return generation;
} catch (WriteStateException ex) {
throw new WriteStateException(false, "[" + index + "]: failed to write index state", ex);
}
}
/**
* Writes the global state, *without* the indices states.
*
* @throws WriteStateException if exception when writing state occurs. {@link WriteStateException#isDirty()} will always return
* false, because new global state file is not yet referenced by manifest file.
*/
long writeGlobalState(String reason, Metadata metadata) throws WriteStateException {
logger.trace("[_global] writing state, reason [{}]", reason);
try {
long generation = METADATA_FORMAT.write(metadata, nodeEnv.nodeDataPaths());
logger.trace("[_global] state written");
return generation;
} catch (WriteStateException ex) {
throw new WriteStateException(false, "[_global]: failed to write global state", ex);
}
}
/**
* Removes old state files in global state directory.
*
* @param currentGeneration current state generation to keep in the directory.
*/
void cleanupGlobalState(long currentGeneration) {
METADATA_FORMAT.cleanupOldFiles(currentGeneration, nodeEnv.nodeDataPaths());
}
/**
* Removes old state files in index directory.
*
* @param index index to perform clean up on.
* @param currentGeneration current state generation to keep in the index directory.
*/
public void cleanupIndex(Index index, long currentGeneration) {
INDEX_METADATA_FORMAT.cleanupOldFiles(currentGeneration, nodeEnv.indexPaths(index));
}
/**
* Creates empty cluster state file on disk, deleting global metadata and unreferencing all index metadata
* (only used for dangling indices at that point).
*/
public void unreferenceAll() throws IOException {
MANIFEST_FORMAT.writeAndCleanup(Manifest.empty(), nodeEnv.nodeDataPaths()); // write empty file so that indices become unreferenced
METADATA_FORMAT.cleanupOldFiles(Long.MAX_VALUE, nodeEnv.nodeDataPaths());
}
/**
* Removes manifest file, global metadata and all index metadata
*/
public void deleteAll() throws IOException {
// To ensure that the metadata is never reimported by loadFullStateBWC in case where the deletions here fail mid-way through,
// we first write an empty manifest file so that the indices become unreferenced, then clean up the indices, and only then delete
// the manifest file.
unreferenceAll();
for (String indexFolderName : nodeEnv.availableIndexFolders()) {
// delete meta state directories of indices
MetadataStateFormat.deleteMetaState(nodeEnv.resolveIndexFolder(indexFolderName));
}
MANIFEST_FORMAT.cleanupOldFiles(Long.MAX_VALUE, nodeEnv.nodeDataPaths()); // finally delete manifest
}
}