Add skeleton structure for tiered-storage module

CHANGELOG.md

@@ -30,6 +30,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 - Add warmup phase to wait for lag to catch up in pull-based ingestion before serving ([#20526](https://github.com/opensearch-project/OpenSearch/pull/20526))
 - Add a new static method to IndicesOptions API to expose `STRICT_EXPAND_OPEN_HIDDEN_FORBID_CLOSED` index option ([#20980](https://github.com/opensearch-project/OpenSearch/pull/20980))
+- Add skeleton structure for tiered-storage module ([#21017](https://github.com/opensearch-project/OpenSearch/pull/21017))
+
 
 ### Changed
 - Make telemetry `Tags` immutable ([#20788](https://github.com/opensearch-project/OpenSearch/pull/20788))

modules/tiered-storage/build.gradle

@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+opensearchplugin {
+  description = 'Module for tiered storage and writable warm index support'
+  classname = 'org.opensearch.storage.TieredStoragePlugin'
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/TieredStoragePlugin.java

@@ -0,0 +1,63 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage;
+
+import org.opensearch.common.SetOnce;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.plugins.ActionPlugin;
+import org.opensearch.plugins.IndexStorePlugin;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.plugins.TelemetryAwarePlugin;
+import org.opensearch.storage.common.tiering.TieringUtils;
+import org.opensearch.storage.metrics.TierActionMetrics;
+import org.opensearch.storage.prefetch.TieredStoragePrefetchSettings;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import static org.opensearch.storage.slowlogs.TieredStorageSearchSlowLog.TIERED_STORAGE_SEARCH_SLOWLOG_SETTINGS;
+
+/**
+ * Plugin to support writable warm index and other related features.
+ * Registers settings, actions, REST handlers, directory factories, and search operation listeners.
+ *
+ * getDirectoryFactories, getCompositeDirectoryFactories, getSettings, getExecutorBuilders,
+ * getActions, getRestHandlers, createComponents, onIndexModule, and createGuiceModules
+ * will be added in the implementation PR.
+ */
+public class TieredStoragePlugin extends Plugin implements IndexStorePlugin, ActionPlugin, TelemetryAwarePlugin {
+
+    /**
+     * Index type for optimised downloads on hot indices.
+     */
+    public static final String HOT_BLOCK_EAGER_FETCH_INDEX_TYPE = "hot_block_eager_fetch";
+    /** Composite index type for tiered storage. */
+    public static final String TIERED_COMPOSITE_INDEX_TYPE = "tiered-storage";
+    private static final String REMOTE_DOWNLOAD = "remote_download";
+
+    private final SetOnce<ThreadPool> threadpool = new SetOnce<>();
+    private TieredStoragePrefetchSettings tieredStoragePrefetchSettings;
+    private TierActionMetrics tierActionMetrics;
+
+    /** Constructs a new TieredStoragePlugin. */
+    public TieredStoragePlugin() {}
+
+    private final List<Setting<?>> tieredStorageSettings = Stream.concat(
+        Stream.of(
+            TieringUtils.H2W_MAX_CONCURRENT_TIEIRNG_REQUESTS,
+            TieringUtils.W2H_MAX_CONCURRENT_TIEIRNG_REQUESTS,
+            TieringUtils.JVM_USAGE_TIERING_THRESHOLD_PERCENT,
+            TieringUtils.FILECACHE_ACTIVE_USAGE_TIERING_THRESHOLD_PERCENT,
+            TieredStoragePrefetchSettings.READ_AHEAD_BLOCK_COUNT,
+            TieredStoragePrefetchSettings.STORED_FIELDS_PREFETCH_ENABLED_SETTING
+        ),
+        TIERED_STORAGE_SEARCH_SLOWLOG_SETTINGS.stream()
+    ).toList();
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/action/tiering/CancelTieringAction.java

@@ -0,0 +1,29 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage.action.tiering;
+
+import org.opensearch.action.ActionType;
+import org.opensearch.action.support.clustermanager.AcknowledgedResponse;
+
+/**
+ * Action for cancelling ongoing tiering operations.
+ * This action can be used to cancel both hot-to-warm and warm-to-hot migrations
+ * when shards get stuck in RUNNING_SHARD_RELOCATION state.
+ */
+public class CancelTieringAction extends ActionType<AcknowledgedResponse> {
+
+    /** Singleton instance. */
+    public static final CancelTieringAction INSTANCE = new CancelTieringAction();
+    /** Action name for cancel tiering. */
+    public static final String NAME = "indices:admin/_tier/cancel";
+
+    private CancelTieringAction() {
+        super(NAME, AcknowledgedResponse::new);
+    }
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/action/tiering/CancelTieringRequest.java

@@ -0,0 +1,70 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage.action.tiering;
+
+import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.action.support.clustermanager.AcknowledgedRequest;
+import org.opensearch.core.common.io.stream.StreamInput;
+
+import java.io.IOException;
+
+/**
+ * Request to cancel an ongoing tiering operation for an index.
+ * This request contains the index name and necessary parameters to safely
+ * cancel migrations that may be stuck in RUNNING_SHARD_RELOCATION state.
+ *
+ * Serialization (writeTo, StreamInput constructor), validation, equals/hashCode, and toString
+ * will be added in the implementation PR.
+ */
+public class CancelTieringRequest extends AcknowledgedRequest<CancelTieringRequest> {
+
+    private String index;
+
+    /** Default constructor. */
+    public CancelTieringRequest() {
+        super();
+    }
+
+    /**
+     * Constructs a request from a stream.
+     * @param in the stream input
+     * @throws IOException if an I/O error occurs
+     */
+    public CancelTieringRequest(StreamInput in) throws IOException {
+        super(in);
+        throw new UnsupportedOperationException("Not yet implemented");
+    }
+
+    /**
+     * Constructs a request for the given index.
+     * @param index the index name
+     */
+    public CancelTieringRequest(final String index) {
+        super();
+        this.index = index;
+    }
+
+    @Override
+    public ActionRequestValidationException validate() {
+        throw new UnsupportedOperationException("Not yet implemented");
+    }
+
+    /** Returns the index name. */
+    public String getIndex() {
+        return index;
+    }
+
+    /**
+     * Sets the index name.
+     * @param index the index name
+     */
+    public void setIndex(String index) {
+        this.index = index;
+    }
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/action/tiering/HotToWarmTierAction.java

@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage.action.tiering;
+
+import org.opensearch.action.ActionType;
+import org.opensearch.action.support.clustermanager.AcknowledgedResponse;
+
+/**
+ * Action type for moving indices from hot to warm tier in OpenSearch's tiered storage.
+ */
+public class HotToWarmTierAction extends ActionType<AcknowledgedResponse> {
+
+    /**
+    * Singleton instance of the HotToWarmTierAction.
+    */
+    public static final HotToWarmTierAction INSTANCE = new HotToWarmTierAction();
+    /**
+     * Action name for hot to warm tier operations.
+     */
+    public static final String NAME = "indices:admin/_tier/hot_to_warm";
+
+    private HotToWarmTierAction() {
+        super(NAME, AcknowledgedResponse::new);
+    }
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/action/tiering/IndexTieringRequest.java

@@ -0,0 +1,64 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage.action.tiering;
+
+import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.action.support.clustermanager.AcknowledgedRequest;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.storage.common.tiering.TieringUtils.Tier;
+
+import java.io.IOException;
+
+/**
+ * Represents a request to move indices between different storage tiers.
+ * This class handles the validation and serialization of tiering requests.
+ *
+ * Serialization (writeTo, StreamInput constructor), validation, equals/hashCode
+ * will be added in the implementation PR.
+ */
+public class IndexTieringRequest extends AcknowledgedRequest<IndexTieringRequest> {
+
+    private final String indexName;
+    private final Tier targetTier;
+
+    /**
+     * Constructs a new tiering request from a stream.
+     * @param in the stream input
+     * @throws IOException if an I/O error occurs
+     */
+    public IndexTieringRequest(StreamInput in) throws IOException {
+        super(in);
+        throw new UnsupportedOperationException("Not yet implemented");
+    }
+
+    /**
+     * Constructs a new tiering request.
+     * @param targetTier the target tier
+     * @param indexName the index name
+     */
+    public IndexTieringRequest(final String targetTier, final String indexName) {
+        this.targetTier = Tier.fromString(targetTier);
+        this.indexName = indexName;
+    }
+
+    @Override
+    public ActionRequestValidationException validate() {
+        throw new UnsupportedOperationException("Not yet implemented");
+    }
+
+    /** Returns the target tier. */
+    public Tier tier() {
+        return targetTier;
+    }
+
+    /** Returns the index name. */
+    public String getIndex() {
+        return indexName;
+    }
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/action/tiering/RestBaseTierAction.java

@@ -0,0 +1,46 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage.action.tiering;
+
+import org.opensearch.rest.BaseRestHandler;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.transport.client.node.NodeClient;
+
+import java.util.List;
+
+import static java.util.Collections.singletonList;
+import static org.opensearch.rest.RestRequest.Method.POST;
+
+/**
+ * Base REST handler for tiering operations.
+ * prepareRequest and validateIndices will be added in the implementation PR.
+ */
+public abstract class RestBaseTierAction extends BaseRestHandler {
+
+    /** The target tier for this action. */
+    protected final String targetTier;
+
+    /**
+     * Constructs a RestBaseTierAction for the given target tier.
+     * @param targetTier the target tier
+     */
+    protected RestBaseTierAction(String targetTier) {
+        this.targetTier = targetTier;
+    }
+
+    @Override
+    public List<Route> routes() {
+        return singletonList(new Route(POST, "/{index}/_tier/" + targetTier));
+    }
+
+    @Override
+    public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) {
+        throw new UnsupportedOperationException("Not yet implemented");
+    }
+}

modules/tiered-storage/src/main/java/org/opensearch/storage/action/tiering/RestCancelTierAction.java

@@ -0,0 +1,46 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.storage.action.tiering;
+
+import org.opensearch.rest.BaseRestHandler;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.transport.client.node.NodeClient;
+
+import java.util.List;
+
+import static java.util.Collections.singletonList;
+import static org.opensearch.rest.RestRequest.Method.POST;
+
+/**
+ * REST handler for cancelling ongoing tiering operations.
+ * This handler provides an endpoint to cancel migrations that may be stuck
+ * in RUNNING_SHARD_RELOCATION state, allowing manual recovery.
+ *
+ * validateIndices and full prepareRequest logic will be added in the implementation PR.
+ */
+public class RestCancelTierAction extends BaseRestHandler {
+
+    /** Constructs a new RestCancelTierAction. */
+    public RestCancelTierAction() {}
+
+    @Override
+    public String getName() {
+        return "cancel_tier_action";
+    }
+
+    @Override
+    public List<Route> routes() {
+        return singletonList(new Route(POST, "/_tier/_cancel/{index}"));
+    }
+
+    @Override
+    protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) {
+        throw new UnsupportedOperationException("Not yet implemented");
+    }
+}