Examples with ClusterStateUpdateTask org.elasticsearch.cluster.ClusterStateUpdateTask used on opensource projects

Example 1 with ClusterStateUpdateTask

use of org.elasticsearch.cluster.ClusterStateUpdateTask in project elasticsearch by elastic.

the class ClusterStateChanges method executeClusterStateUpdateTask.

private ClusterState executeClusterStateUpdateTask(ClusterState state, Runnable runnable) {
    ClusterState[] result = new ClusterState[1];
    doAnswer(invocationOnMock -> {
        ClusterStateUpdateTask task = (ClusterStateUpdateTask) invocationOnMock.getArguments()[1];
        result[0] = task.execute(state);
        return null;
    }).when(clusterService).submitStateUpdateTask(anyString(), any(ClusterStateUpdateTask.class));
    runnable.run();
    assertThat(result[0], notNullValue());
    return result[0];
}

Example 2 with ClusterStateUpdateTask

use of org.elasticsearch.cluster.ClusterStateUpdateTask in project elasticsearch by elastic.

the class RestoreService method restoreSnapshot.

/**
     * Restores snapshot specified in the restore request.
     *
     * @param request  restore request
     * @param listener restore listener
     */
public void restoreSnapshot(final RestoreRequest request, final ActionListener<RestoreCompletionResponse> listener) {
    try {
        // Read snapshot info and metadata from the repository
        Repository repository = repositoriesService.repository(request.repositoryName);
        final RepositoryData repositoryData = repository.getRepositoryData();
        final Optional<SnapshotId> incompatibleSnapshotId = repositoryData.getIncompatibleSnapshotIds().stream().filter(s -> request.snapshotName.equals(s.getName())).findFirst();
        if (incompatibleSnapshotId.isPresent()) {
            throw new SnapshotRestoreException(request.repositoryName, request.snapshotName, "cannot restore incompatible snapshot");
        }
        final Optional<SnapshotId> matchingSnapshotId = repositoryData.getSnapshotIds().stream().filter(s -> request.snapshotName.equals(s.getName())).findFirst();
        if (matchingSnapshotId.isPresent() == false) {
            throw new SnapshotRestoreException(request.repositoryName, request.snapshotName, "snapshot does not exist");
        }
        final SnapshotId snapshotId = matchingSnapshotId.get();
        final SnapshotInfo snapshotInfo = repository.getSnapshotInfo(snapshotId);
        final Snapshot snapshot = new Snapshot(request.repositoryName, snapshotId);
        List<String> filteredIndices = SnapshotUtils.filterIndices(snapshotInfo.indices(), request.indices(), request.indicesOptions());
        MetaData metaData = repository.getSnapshotMetaData(snapshotInfo, repositoryData.resolveIndices(filteredIndices));
        // Make sure that we can restore from this snapshot
        validateSnapshotRestorable(request.repositoryName, snapshotInfo);
        // Find list of indices that we need to restore
        final Map<String, String> renamedIndices = renamedIndices(request, filteredIndices);
        // Now we can start the actual restore process by adding shards to be recovered in the cluster state
        // and updating cluster metadata (global and index) as needed
        clusterService.submitStateUpdateTask(request.cause(), new ClusterStateUpdateTask() {

            RestoreInfo restoreInfo = null;

            @Override
            public ClusterState execute(ClusterState currentState) {
                // Check if another restore process is already running - cannot run two restore processes at the
                // same time
                RestoreInProgress restoreInProgress = currentState.custom(RestoreInProgress.TYPE);
                if (restoreInProgress != null && !restoreInProgress.entries().isEmpty()) {
                    throw new ConcurrentSnapshotExecutionException(snapshot, "Restore process is already running in this cluster");
                }
                // Check if the snapshot to restore is currently being deleted
                SnapshotDeletionsInProgress deletionsInProgress = currentState.custom(SnapshotDeletionsInProgress.TYPE);
                if (deletionsInProgress != null && deletionsInProgress.hasDeletionsInProgress()) {
                    throw new ConcurrentSnapshotExecutionException(snapshot, "cannot restore a snapshot while a snapshot deletion is in-progress [" + deletionsInProgress.getEntries().get(0).getSnapshot() + "]");
                }
                // Updating cluster state
                ClusterState.Builder builder = ClusterState.builder(currentState);
                MetaData.Builder mdBuilder = MetaData.builder(currentState.metaData());
                ClusterBlocks.Builder blocks = ClusterBlocks.builder().blocks(currentState.blocks());
                RoutingTable.Builder rtBuilder = RoutingTable.builder(currentState.routingTable());
                ImmutableOpenMap<ShardId, RestoreInProgress.ShardRestoreStatus> shards;
                Set<String> aliases = new HashSet<>();
                if (!renamedIndices.isEmpty()) {
                    // We have some indices to restore
                    ImmutableOpenMap.Builder<ShardId, RestoreInProgress.ShardRestoreStatus> shardsBuilder = ImmutableOpenMap.builder();
                    final Version minIndexCompatibilityVersion = currentState.getNodes().getMaxNodeVersion().minimumIndexCompatibilityVersion();
                    for (Map.Entry<String, String> indexEntry : renamedIndices.entrySet()) {
                        String index = indexEntry.getValue();
                        boolean partial = checkPartial(index);
                        SnapshotRecoverySource recoverySource = new SnapshotRecoverySource(snapshot, snapshotInfo.version(), index);
                        String renamedIndexName = indexEntry.getKey();
                        IndexMetaData snapshotIndexMetaData = metaData.index(index);
                        snapshotIndexMetaData = updateIndexSettings(snapshotIndexMetaData, request.indexSettings, request.ignoreIndexSettings);
                        try {
                            snapshotIndexMetaData = metaDataIndexUpgradeService.upgradeIndexMetaData(snapshotIndexMetaData, minIndexCompatibilityVersion);
                        } catch (Exception ex) {
                            throw new SnapshotRestoreException(snapshot, "cannot restore index [" + index + "] because it cannot be upgraded", ex);
                        }
                        // Check that the index is closed or doesn't exist
                        IndexMetaData currentIndexMetaData = currentState.metaData().index(renamedIndexName);
                        IntSet ignoreShards = new IntHashSet();
                        final Index renamedIndex;
                        if (currentIndexMetaData == null) {
                            // Index doesn't exist - create it and start recovery
                            // Make sure that the index we are about to create has a validate name
                            MetaDataCreateIndexService.validateIndexName(renamedIndexName, currentState);
                            createIndexService.validateIndexSettings(renamedIndexName, snapshotIndexMetaData.getSettings());
                            IndexMetaData.Builder indexMdBuilder = IndexMetaData.builder(snapshotIndexMetaData).state(IndexMetaData.State.OPEN).index(renamedIndexName);
                            indexMdBuilder.settings(Settings.builder().put(snapshotIndexMetaData.getSettings()).put(IndexMetaData.SETTING_INDEX_UUID, UUIDs.randomBase64UUID()));
                            if (!request.includeAliases() && !snapshotIndexMetaData.getAliases().isEmpty()) {
                                // Remove all aliases - they shouldn't be restored
                                indexMdBuilder.removeAllAliases();
                            } else {
                                for (ObjectCursor<String> alias : snapshotIndexMetaData.getAliases().keys()) {
                                    aliases.add(alias.value);
                                }
                            }
                            IndexMetaData updatedIndexMetaData = indexMdBuilder.build();
                            if (partial) {
                                populateIgnoredShards(index, ignoreShards);
                            }
                            rtBuilder.addAsNewRestore(updatedIndexMetaData, recoverySource, ignoreShards);
                            blocks.addBlocks(updatedIndexMetaData);
                            mdBuilder.put(updatedIndexMetaData, true);
                            renamedIndex = updatedIndexMetaData.getIndex();
                        } else {
                            validateExistingIndex(currentIndexMetaData, snapshotIndexMetaData, renamedIndexName, partial);
                            // Index exists and it's closed - open it in metadata and start recovery
                            IndexMetaData.Builder indexMdBuilder = IndexMetaData.builder(snapshotIndexMetaData).state(IndexMetaData.State.OPEN);
                            indexMdBuilder.version(Math.max(snapshotIndexMetaData.getVersion(), currentIndexMetaData.getVersion() + 1));
                            if (!request.includeAliases()) {
                                // Remove all snapshot aliases
                                if (!snapshotIndexMetaData.getAliases().isEmpty()) {
                                    indexMdBuilder.removeAllAliases();
                                }
                                /// Add existing aliases
                                for (ObjectCursor<AliasMetaData> alias : currentIndexMetaData.getAliases().values()) {
                                    indexMdBuilder.putAlias(alias.value);
                                }
                            } else {
                                for (ObjectCursor<String> alias : snapshotIndexMetaData.getAliases().keys()) {
                                    aliases.add(alias.value);
                                }
                            }
                            indexMdBuilder.settings(Settings.builder().put(snapshotIndexMetaData.getSettings()).put(IndexMetaData.SETTING_INDEX_UUID, currentIndexMetaData.getIndexUUID()));
                            IndexMetaData updatedIndexMetaData = indexMdBuilder.index(renamedIndexName).build();
                            rtBuilder.addAsRestore(updatedIndexMetaData, recoverySource);
                            blocks.updateBlocks(updatedIndexMetaData);
                            mdBuilder.put(updatedIndexMetaData, true);
                            renamedIndex = updatedIndexMetaData.getIndex();
                        }
                        for (int shard = 0; shard < snapshotIndexMetaData.getNumberOfShards(); shard++) {
                            if (!ignoreShards.contains(shard)) {
                                shardsBuilder.put(new ShardId(renamedIndex, shard), new RestoreInProgress.ShardRestoreStatus(clusterService.state().nodes().getLocalNodeId()));
                            } else {
                                shardsBuilder.put(new ShardId(renamedIndex, shard), new RestoreInProgress.ShardRestoreStatus(clusterService.state().nodes().getLocalNodeId(), RestoreInProgress.State.FAILURE));
                            }
                        }
                    }
                    shards = shardsBuilder.build();
                    RestoreInProgress.Entry restoreEntry = new RestoreInProgress.Entry(snapshot, overallState(RestoreInProgress.State.INIT, shards), Collections.unmodifiableList(new ArrayList<>(renamedIndices.keySet())), shards);
                    builder.putCustom(RestoreInProgress.TYPE, new RestoreInProgress(restoreEntry));
                } else {
                    shards = ImmutableOpenMap.of();
                }
                checkAliasNameConflicts(renamedIndices, aliases);
                // Restore global state if needed
                restoreGlobalStateIfRequested(mdBuilder);
                if (completed(shards)) {
                    // We don't have any indices to restore - we are done
                    restoreInfo = new RestoreInfo(snapshotId.getName(), Collections.unmodifiableList(new ArrayList<>(renamedIndices.keySet())), shards.size(), shards.size() - failedShards(shards));
                }
                RoutingTable rt = rtBuilder.build();
                ClusterState updatedState = builder.metaData(mdBuilder).blocks(blocks).routingTable(rt).build();
                return allocationService.reroute(updatedState, "restored snapshot [" + snapshot + "]");
            }

            private void checkAliasNameConflicts(Map<String, String> renamedIndices, Set<String> aliases) {
                for (Map.Entry<String, String> renamedIndex : renamedIndices.entrySet()) {
                    if (aliases.contains(renamedIndex.getKey())) {
                        throw new SnapshotRestoreException(snapshot, "cannot rename index [" + renamedIndex.getValue() + "] into [" + renamedIndex.getKey() + "] because of conflict with an alias with the same name");
                    }
                }
            }

            private void populateIgnoredShards(String index, IntSet ignoreShards) {
                for (SnapshotShardFailure failure : snapshotInfo.shardFailures()) {
                    if (index.equals(failure.index())) {
                        ignoreShards.add(failure.shardId());
                    }
                }
            }

            private boolean checkPartial(String index) {
                // Make sure that index was fully snapshotted
                if (failed(snapshotInfo, index)) {
                    if (request.partial()) {
                        return true;
                    } else {
                        throw new SnapshotRestoreException(snapshot, "index [" + index + "] wasn't fully snapshotted - cannot restore");
                    }
                } else {
                    return false;
                }
            }

            private void validateExistingIndex(IndexMetaData currentIndexMetaData, IndexMetaData snapshotIndexMetaData, String renamedIndex, boolean partial) {
                // Index exist - checking that it's closed
                if (currentIndexMetaData.getState() != IndexMetaData.State.CLOSE) {
                    // TODO: Enable restore for open indices
                    throw new SnapshotRestoreException(snapshot, "cannot restore index [" + renamedIndex + "] because it's open");
                }
                // Index exist - checking if it's partial restore
                if (partial) {
                    throw new SnapshotRestoreException(snapshot, "cannot restore partial index [" + renamedIndex + "] because such index already exists");
                }
                // Make sure that the number of shards is the same. That's the only thing that we cannot change
                if (currentIndexMetaData.getNumberOfShards() != snapshotIndexMetaData.getNumberOfShards()) {
                    throw new SnapshotRestoreException(snapshot, "cannot restore index [" + renamedIndex + "] with [" + currentIndexMetaData.getNumberOfShards() + "] shard from snapshot with [" + snapshotIndexMetaData.getNumberOfShards() + "] shards");
                }
            }

            /**
                 * Optionally updates index settings in indexMetaData by removing settings listed in ignoreSettings and
                 * merging them with settings in changeSettings.
                 */
            private IndexMetaData updateIndexSettings(IndexMetaData indexMetaData, Settings changeSettings, String[] ignoreSettings) {
                if (changeSettings.names().isEmpty() && ignoreSettings.length == 0) {
                    return indexMetaData;
                }
                Settings normalizedChangeSettings = Settings.builder().put(changeSettings).normalizePrefix(IndexMetaData.INDEX_SETTING_PREFIX).build();
                IndexMetaData.Builder builder = IndexMetaData.builder(indexMetaData);
                Map<String, String> settingsMap = new HashMap<>(indexMetaData.getSettings().getAsMap());
                List<String> simpleMatchPatterns = new ArrayList<>();
                for (String ignoredSetting : ignoreSettings) {
                    if (!Regex.isSimpleMatchPattern(ignoredSetting)) {
                        if (UNREMOVABLE_SETTINGS.contains(ignoredSetting)) {
                            throw new SnapshotRestoreException(snapshot, "cannot remove setting [" + ignoredSetting + "] on restore");
                        } else {
                            settingsMap.remove(ignoredSetting);
                        }
                    } else {
                        simpleMatchPatterns.add(ignoredSetting);
                    }
                }
                if (!simpleMatchPatterns.isEmpty()) {
                    String[] removePatterns = simpleMatchPatterns.toArray(new String[simpleMatchPatterns.size()]);
                    Iterator<Map.Entry<String, String>> iterator = settingsMap.entrySet().iterator();
                    while (iterator.hasNext()) {
                        Map.Entry<String, String> entry = iterator.next();
                        if (UNREMOVABLE_SETTINGS.contains(entry.getKey()) == false) {
                            if (Regex.simpleMatch(removePatterns, entry.getKey())) {
                                iterator.remove();
                            }
                        }
                    }
                }
                for (Map.Entry<String, String> entry : normalizedChangeSettings.getAsMap().entrySet()) {
                    if (UNMODIFIABLE_SETTINGS.contains(entry.getKey())) {
                        throw new SnapshotRestoreException(snapshot, "cannot modify setting [" + entry.getKey() + "] on restore");
                    } else {
                        settingsMap.put(entry.getKey(), entry.getValue());
                    }
                }
                return builder.settings(Settings.builder().put(settingsMap)).build();
            }

            private void restoreGlobalStateIfRequested(MetaData.Builder mdBuilder) {
                if (request.includeGlobalState()) {
                    if (metaData.persistentSettings() != null) {
                        Settings settings = metaData.persistentSettings();
                        clusterSettings.validateUpdate(settings);
                        mdBuilder.persistentSettings(settings);
                    }
                    if (metaData.templates() != null) {
                        // TODO: Should all existing templates be deleted first?
                        for (ObjectCursor<IndexTemplateMetaData> cursor : metaData.templates().values()) {
                            mdBuilder.put(cursor.value);
                        }
                    }
                    if (metaData.customs() != null) {
                        for (ObjectObjectCursor<String, MetaData.Custom> cursor : metaData.customs()) {
                            if (!RepositoriesMetaData.TYPE.equals(cursor.key)) {
                                // Don't restore repositories while we are working with them
                                // TODO: Should we restore them at the end?
                                mdBuilder.putCustom(cursor.key, cursor.value);
                            }
                        }
                    }
                }
            }

            @Override
            public void onFailure(String source, Exception e) {
                logger.warn((Supplier<?>) () -> new ParameterizedMessage("[{}] failed to restore snapshot", snapshotId), e);
                listener.onFailure(e);
            }

            @Override
            public TimeValue timeout() {
                return request.masterNodeTimeout();
            }

            @Override
            public void clusterStateProcessed(String source, ClusterState oldState, ClusterState newState) {
                listener.onResponse(new RestoreCompletionResponse(snapshot, restoreInfo));
            }
        });
    } catch (Exception e) {
        logger.warn((Supplier<?>) () -> new ParameterizedMessage("[{}] failed to restore snapshot", request.repositoryName + ":" + request.snapshotName), e);
        listener.onFailure(e);
    }
}

Example 3 with ClusterStateUpdateTask

use of org.elasticsearch.cluster.ClusterStateUpdateTask in project elasticsearch by elastic.

the class SnapshotsService method createSnapshot.

/**
     * Initializes the snapshotting process.
     * <p>
     * This method is used by clients to start snapshot. It makes sure that there is no snapshots are currently running and
     * creates a snapshot record in cluster state metadata.
     *
     * @param request  snapshot request
     * @param listener snapshot creation listener
     */
public void createSnapshot(final SnapshotRequest request, final CreateSnapshotListener listener) {
    final String repositoryName = request.repositoryName;
    final String snapshotName = request.snapshotName;
    validate(repositoryName, snapshotName);
    // new UUID for the snapshot
    final SnapshotId snapshotId = new SnapshotId(snapshotName, UUIDs.randomBase64UUID());
    final RepositoryData repositoryData = repositoriesService.repository(repositoryName).getRepositoryData();
    clusterService.submitStateUpdateTask(request.cause(), new ClusterStateUpdateTask() {

        private SnapshotsInProgress.Entry newSnapshot = null;

        @Override
        public ClusterState execute(ClusterState currentState) {
            validate(request, currentState);
            SnapshotDeletionsInProgress deletionsInProgress = currentState.custom(SnapshotDeletionsInProgress.TYPE);
            if (deletionsInProgress != null && deletionsInProgress.hasDeletionsInProgress()) {
                throw new ConcurrentSnapshotExecutionException(repositoryName, snapshotName, "cannot snapshot while a snapshot deletion is in-progress");
            }
            SnapshotsInProgress snapshots = currentState.custom(SnapshotsInProgress.TYPE);
            if (snapshots == null || snapshots.entries().isEmpty()) {
                // Store newSnapshot here to be processed in clusterStateProcessed
                List<String> indices = Arrays.asList(indexNameExpressionResolver.concreteIndexNames(currentState, request.indicesOptions(), request.indices()));
                logger.trace("[{}][{}] creating snapshot for indices [{}]", repositoryName, snapshotName, indices);
                List<IndexId> snapshotIndices = repositoryData.resolveNewIndices(indices);
                newSnapshot = new SnapshotsInProgress.Entry(new Snapshot(repositoryName, snapshotId), request.includeGlobalState(), request.partial(), State.INIT, snapshotIndices, System.currentTimeMillis(), repositoryData.getGenId(), null);
                snapshots = new SnapshotsInProgress(newSnapshot);
            } else {
                throw new ConcurrentSnapshotExecutionException(repositoryName, snapshotName, "a snapshot is already running");
            }
            return ClusterState.builder(currentState).putCustom(SnapshotsInProgress.TYPE, snapshots).build();
        }

        @Override
        public void onFailure(String source, Exception e) {
            logger.warn((Supplier<?>) () -> new ParameterizedMessage("[{}][{}] failed to create snapshot", repositoryName, snapshotName), e);
            newSnapshot = null;
            listener.onFailure(e);
        }

        @Override
        public void clusterStateProcessed(String source, ClusterState oldState, final ClusterState newState) {
            if (newSnapshot != null) {
                threadPool.executor(ThreadPool.Names.SNAPSHOT).execute(() -> beginSnapshot(newState, newSnapshot, request.partial(), listener));
            }
        }

        @Override
        public TimeValue timeout() {
            return request.masterNodeTimeout();
        }
    });
}

Example 4 with ClusterStateUpdateTask

use of org.elasticsearch.cluster.ClusterStateUpdateTask in project elasticsearch by elastic.

the class SnapshotsService method processSnapshotsOnRemovedNodes.

/**
     * Cleans up shard snapshots that were running on removed nodes
     *
     * @param event cluster changed event
     */
private void processSnapshotsOnRemovedNodes(ClusterChangedEvent event) {
    if (removedNodesCleanupNeeded(event)) {
        // Check if we just became the master
        final boolean newMaster = !event.previousState().nodes().isLocalNodeElectedMaster();
        clusterService.submitStateUpdateTask("update snapshot state after node removal", new ClusterStateUpdateTask() {

            @Override
            public ClusterState execute(ClusterState currentState) throws Exception {
                DiscoveryNodes nodes = currentState.nodes();
                SnapshotsInProgress snapshots = currentState.custom(SnapshotsInProgress.TYPE);
                if (snapshots == null) {
                    return currentState;
                }
                boolean changed = false;
                ArrayList<SnapshotsInProgress.Entry> entries = new ArrayList<>();
                for (final SnapshotsInProgress.Entry snapshot : snapshots.entries()) {
                    SnapshotsInProgress.Entry updatedSnapshot = snapshot;
                    boolean snapshotChanged = false;
                    if (snapshot.state() == State.STARTED || snapshot.state() == State.ABORTED) {
                        ImmutableOpenMap.Builder<ShardId, ShardSnapshotStatus> shards = ImmutableOpenMap.builder();
                        for (ObjectObjectCursor<ShardId, ShardSnapshotStatus> shardEntry : snapshot.shards()) {
                            ShardSnapshotStatus shardStatus = shardEntry.value;
                            if (!shardStatus.state().completed() && shardStatus.nodeId() != null) {
                                if (nodes.nodeExists(shardStatus.nodeId())) {
                                    shards.put(shardEntry.key, shardEntry.value);
                                } else {
                                    // TODO: Restart snapshot on another node?
                                    snapshotChanged = true;
                                    logger.warn("failing snapshot of shard [{}] on closed node [{}]", shardEntry.key, shardStatus.nodeId());
                                    shards.put(shardEntry.key, new ShardSnapshotStatus(shardStatus.nodeId(), State.FAILED, "node shutdown"));
                                }
                            }
                        }
                        if (snapshotChanged) {
                            changed = true;
                            ImmutableOpenMap<ShardId, ShardSnapshotStatus> shardsMap = shards.build();
                            if (!snapshot.state().completed() && completed(shardsMap.values())) {
                                updatedSnapshot = new SnapshotsInProgress.Entry(snapshot, State.SUCCESS, shardsMap);
                                endSnapshot(updatedSnapshot);
                            } else {
                                updatedSnapshot = new SnapshotsInProgress.Entry(snapshot, snapshot.state(), shardsMap);
                            }
                        }
                        entries.add(updatedSnapshot);
                    } else if (snapshot.state() == State.INIT && newMaster) {
                        // Clean up the snapshot that failed to start from the old master
                        deleteSnapshot(snapshot.snapshot(), new DeleteSnapshotListener() {

                            @Override
                            public void onResponse() {
                                logger.debug("cleaned up abandoned snapshot {} in INIT state", snapshot.snapshot());
                            }

                            @Override
                            public void onFailure(Exception e) {
                                logger.warn("failed to clean up abandoned snapshot {} in INIT state", snapshot.snapshot());
                            }
                        }, updatedSnapshot.getRepositoryStateId(), false);
                    } else if (snapshot.state() == State.SUCCESS && newMaster) {
                        // Finalize the snapshot
                        endSnapshot(snapshot);
                    }
                }
                if (changed) {
                    snapshots = new SnapshotsInProgress(entries.toArray(new SnapshotsInProgress.Entry[entries.size()]));
                    return ClusterState.builder(currentState).putCustom(SnapshotsInProgress.TYPE, snapshots).build();
                }
                return currentState;
            }

            @Override
            public void onFailure(String source, Exception e) {
                logger.warn("failed to update snapshot state after node removal");
            }
        });
    }
}

Example 5 with ClusterStateUpdateTask

use of org.elasticsearch.cluster.ClusterStateUpdateTask in project elasticsearch by elastic.

the class SnapshotsService method deleteSnapshot.

/**
     * Deletes snapshot from repository.
     * <p>
     * If the snapshot is still running cancels the snapshot first and then deletes it from the repository.
     *
     * @param snapshot snapshot
     * @param listener listener
     * @param repositoryStateId the unique id for the state of the repository
     */
private void deleteSnapshot(final Snapshot snapshot, final DeleteSnapshotListener listener, final long repositoryStateId, final boolean immediatePriority) {
    Priority priority = immediatePriority ? Priority.IMMEDIATE : Priority.NORMAL;
    clusterService.submitStateUpdateTask("delete snapshot", new ClusterStateUpdateTask(priority) {

        boolean waitForSnapshot = false;

        @Override
        public ClusterState execute(ClusterState currentState) throws Exception {
            SnapshotDeletionsInProgress deletionsInProgress = currentState.custom(SnapshotDeletionsInProgress.TYPE);
            if (deletionsInProgress != null && deletionsInProgress.hasDeletionsInProgress()) {
                throw new ConcurrentSnapshotExecutionException(snapshot, "cannot delete - another snapshot is currently being deleted");
            }
            RestoreInProgress restoreInProgress = currentState.custom(RestoreInProgress.TYPE);
            if (restoreInProgress != null) {
                // and the files the restore depends on would all be gone
                if (restoreInProgress.entries().isEmpty() == false) {
                    throw new ConcurrentSnapshotExecutionException(snapshot, "cannot delete snapshot during a restore");
                }
            }
            ClusterState.Builder clusterStateBuilder = ClusterState.builder(currentState);
            SnapshotsInProgress snapshots = currentState.custom(SnapshotsInProgress.TYPE);
            SnapshotsInProgress.Entry snapshotEntry = snapshots != null ? snapshots.snapshot(snapshot) : null;
            if (snapshotEntry == null) {
                // This snapshot is not running - delete
                if (snapshots != null && !snapshots.entries().isEmpty()) {
                    // However other snapshots are running - cannot continue
                    throw new ConcurrentSnapshotExecutionException(snapshot, "another snapshot is currently running cannot delete");
                }
                // add the snapshot deletion to the cluster state
                SnapshotDeletionsInProgress.Entry entry = new SnapshotDeletionsInProgress.Entry(snapshot, System.currentTimeMillis(), repositoryStateId);
                if (deletionsInProgress != null) {
                    deletionsInProgress = deletionsInProgress.withAddedEntry(entry);
                } else {
                    deletionsInProgress = SnapshotDeletionsInProgress.newInstance(entry);
                }
                clusterStateBuilder.putCustom(SnapshotDeletionsInProgress.TYPE, deletionsInProgress);
            } else {
                // This snapshot is currently running - stopping shards first
                waitForSnapshot = true;
                ImmutableOpenMap<ShardId, ShardSnapshotStatus> shards;
                if (snapshotEntry.state() == State.STARTED && snapshotEntry.shards() != null) {
                    // snapshot is currently running - stop started shards
                    ImmutableOpenMap.Builder<ShardId, ShardSnapshotStatus> shardsBuilder = ImmutableOpenMap.builder();
                    for (ObjectObjectCursor<ShardId, ShardSnapshotStatus> shardEntry : snapshotEntry.shards()) {
                        ShardSnapshotStatus status = shardEntry.value;
                        if (!status.state().completed()) {
                            shardsBuilder.put(shardEntry.key, new ShardSnapshotStatus(status.nodeId(), State.ABORTED));
                        } else {
                            shardsBuilder.put(shardEntry.key, status);
                        }
                    }
                    shards = shardsBuilder.build();
                } else if (snapshotEntry.state() == State.INIT) {
                    // snapshot hasn't started yet - end it
                    shards = snapshotEntry.shards();
                    endSnapshot(snapshotEntry);
                } else {
                    boolean hasUncompletedShards = false;
                    // Cleanup in case a node gone missing and snapshot wasn't updated for some reason
                    for (ObjectCursor<ShardSnapshotStatus> shardStatus : snapshotEntry.shards().values()) {
                        // Check if we still have shard running on existing nodes
                        if (shardStatus.value.state().completed() == false && shardStatus.value.nodeId() != null && currentState.nodes().get(shardStatus.value.nodeId()) != null) {
                            hasUncompletedShards = true;
                            break;
                        }
                    }
                    if (hasUncompletedShards) {
                        // snapshot is being finalized - wait for shards to complete finalization process
                        logger.debug("trying to delete completed snapshot - should wait for shards to finalize on all nodes");
                        return currentState;
                    } else {
                        // no shards to wait for - finish the snapshot
                        logger.debug("trying to delete completed snapshot with no finalizing shards - can delete immediately");
                        shards = snapshotEntry.shards();
                        endSnapshot(snapshotEntry);
                    }
                }
                SnapshotsInProgress.Entry newSnapshot = new SnapshotsInProgress.Entry(snapshotEntry, State.ABORTED, shards);
                snapshots = new SnapshotsInProgress(newSnapshot);
                clusterStateBuilder.putCustom(SnapshotsInProgress.TYPE, snapshots);
            }
            return clusterStateBuilder.build();
        }

        @Override
        public void onFailure(String source, Exception e) {
            listener.onFailure(e);
        }

        @Override
        public void clusterStateProcessed(String source, ClusterState oldState, ClusterState newState) {
            if (waitForSnapshot) {
                logger.trace("adding snapshot completion listener to wait for deleted snapshot to finish");
                addListener(new SnapshotCompletionListener() {

                    @Override
                    public void onSnapshotCompletion(Snapshot completedSnapshot, SnapshotInfo snapshotInfo) {
                        if (completedSnapshot.equals(snapshot)) {
                            logger.trace("deleted snapshot completed - deleting files");
                            removeListener(this);
                            threadPool.executor(ThreadPool.Names.SNAPSHOT).execute(() -> deleteSnapshot(completedSnapshot.getRepository(), completedSnapshot.getSnapshotId().getName(), listener, true));
                        }
                    }

                    @Override
                    public void onSnapshotFailure(Snapshot failedSnapshot, Exception e) {
                        if (failedSnapshot.equals(snapshot)) {
                            logger.trace("deleted snapshot failed - deleting files", e);
                            removeListener(this);
                            threadPool.executor(ThreadPool.Names.SNAPSHOT).execute(() -> deleteSnapshot(failedSnapshot.getRepository(), failedSnapshot.getSnapshotId().getName(), listener, true));
                        }
                    }
                });
            } else {
                logger.trace("deleted snapshot is not running - deleting files");
                deleteSnapshotFromRepository(snapshot, listener, repositoryStateId);
            }
        }
    });
}