[Backport 2.x] [Offline Nodes] Adds new library for offline tasks

CHANGELOG.md

@@ -5,9 +5,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased 2.x]
 ### Added
+- [Offline Nodes] Adds offline-tasks library containing various interfaces to be used for Offline Background Tasks. ([#13574](https://github.com/opensearch-project/OpenSearch/pull/13574))
+- Fix for hasInitiatedFetching to fix allocation explain and manual reroute APIs (([#14972](https://github.com/opensearch-project/OpenSearch/pull/14972))
 - Add path prefix support to hashed prefix snapshots ([#15664](https://github.com/opensearch-project/OpenSearch/pull/15664))
 - [Workload Management] QueryGroup resource cancellation framework changes ([#15651](https://github.com/opensearch-project/OpenSearch/pull/15651))
 
+
 ### Dependencies
 - Bump `com.azure:azure-identity` from 1.13.0 to 1.13.2 ([#15578](https://github.com/opensearch-project/OpenSearch/pull/15578))
 - Bump `protobuf` from 3.22.3 to 3.25.4 ([#15684](https://github.com/opensearch-project/OpenSearch/pull/15684))

libs/task-commons/build.gradle

@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+
+dependencies {
+  api project(':libs:opensearch-common')
+
+  testImplementation "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${versions.randomizedrunner}"
+  testImplementation "junit:junit:${versions.junit}"
+  testImplementation "org.hamcrest:hamcrest:${versions.hamcrest}"
+  testImplementation(project(":test:framework")) {
+    exclude group: 'org.opensearch', module: 'opensearch-task-commons'
+  }
+}
+
+tasks.named('forbiddenApisMain').configure {
+  replaceSignatureFiles 'jdk-signatures'
+}

libs/task-commons/src/main/java/org/opensearch/task/commons/clients/TaskListRequest.java

@@ -0,0 +1,103 @@
+/*
+ * 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.task.commons.clients;
+
+import org.opensearch.task.commons.task.TaskStatus;
+import org.opensearch.task.commons.task.TaskType;
+import org.opensearch.task.commons.worker.WorkerNode;
+
+/**
+ * Request object for listing tasks
+ */
+public class TaskListRequest {
+
+    /**
+     * Filters listTasks response by specific task status'
+     */
+    private TaskStatus[] taskStatus;
+
+    /**
+     * Filter listTasks response by specific task types
+     */
+    private TaskType[] taskTypes;
+
+    /**
+     * Filter listTasks response by specific worker node
+     */
+    private WorkerNode workerNodes;
+
+    /**
+     * Depicts the start page number for the list call.
+     *
+     * @see TaskManagerClient#listTasks(TaskListRequest)
+     */
+    private int startPageNumber;
+
+    /**
+     * Depicts the page size for the list call.
+     *
+     * @see TaskManagerClient#listTasks(TaskListRequest)
+     */
+    private int pageSize;
+
+    /**
+     * Default constructor
+     */
+    public TaskListRequest() {}
+
+    /**
+     * Update task types to filter with in the request
+     * @param taskTypes TaskType[]
+     * @return ListTaskRequest
+     */
+    public TaskListRequest taskType(TaskType... taskTypes) {
+        this.taskTypes = taskTypes;
+        return this;
+    }
+
+    /**
+     * Update task status to filter with in the request
+     * @param taskStatus TaskStatus[]
+     * @return ListTaskRequest
+     */
+    public TaskListRequest taskType(TaskStatus... taskStatus) {
+        this.taskStatus = taskStatus;
+        return this;
+    }
+
+    /**
+     * Update worker node to filter with in the request
+     * @param workerNode WorkerNode
+     * @return ListTaskRequest
+     */
+    private TaskListRequest workerNode(WorkerNode workerNode) {
+        this.workerNodes = workerNode;
+        return this;
+    }
+
+    /**
+     * Update page number to start with when fetching the list of tasks
+     * @param startPageNumber startPageNumber
+     * @return ListTaskRequest
+     */
+    public TaskListRequest startPageNumber(int startPageNumber) {
+        this.startPageNumber = startPageNumber;
+        return this;
+    }
+
+    /**
+     * Update page size for the list tasks response
+     * @param pageSize int
+     * @return ListTaskRequest
+     */
+    public TaskListRequest pageSize(int pageSize) {
+        this.pageSize = pageSize;
+        return this;
+    }
+}

libs/task-commons/src/main/java/org/opensearch/task/commons/clients/TaskManagerClient.java

@@ -0,0 +1,69 @@
+/*
+ * 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.task.commons.clients;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+import org.opensearch.task.commons.task.Task;
+import org.opensearch.task.commons.task.TaskId;
+import org.opensearch.task.commons.worker.WorkerNode;
+
+import java.util.List;
+
+/**
+ * Client used to interact with Task Store/Queue.
+ *
+ * TODO: TaskManager can be something not running an opensearch process.
+ * We need to come up with a way to allow this interface to be used with in and out opensearch as well
+ *
+ * @opensearch.experimental
+ */
+@ExperimentalApi
+public interface TaskManagerClient {
+
+    /**
+     * Get task from TaskStore/Queue
+     *
+     * @param taskId TaskId of the task to be retrieved
+     * @return Task corresponding to TaskId
+     */
+    Task getTask(TaskId taskId);
+
+    /**
+     * Update task in TaskStore/Queue
+     *
+     * @param task Task to be updated
+     */
+    void updateTask(Task task);
+
+    /**
+     * Mark task as cancelled.
+     * Ongoing Tasks can be cancelled as well if the corresponding worker supports cancellation
+     *
+     * @param taskId TaskId of the task to be cancelled
+     */
+    void cancelTask(TaskId taskId);
+
+    /**
+     * List all tasks applying all the filters present in listTaskRequest
+     *
+     * @param taskListRequest TaskListRequest
+     * @return list of all the task matching the filters in listTaskRequest
+     */
+    List<Task> listTasks(TaskListRequest taskListRequest);
+
+    /**
+     * Assign Task to a particular WorkerNode. This ensures no 2 worker Nodes work on the same task.
+     * This API can be used in both pull and push models of task assignment.
+     *
+     * @param taskId TaskId of the task to be assigned
+     * @param node WorkerNode task is being assigned to
+     * @return true if task is assigned successfully, false otherwise
+     */
+    boolean assignTask(TaskId taskId, WorkerNode node);
+}

libs/task-commons/src/main/java/org/opensearch/task/commons/clients/TaskProducerClient.java

@@ -0,0 +1,24 @@
+/*
+ * 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.task.commons.clients;
+
+import org.opensearch.task.commons.task.Task;
+
+/**
+ * Producer interface used to submit new tasks for execution on worker nodes.
+ */
+public interface TaskProducerClient {
+
+    /**
+     * Submit a new task to TaskStore/Queue
+     *
+     * @param task Task to be submitted for execution on offline nodes
+     */
+    void submitTask(Task task);
+}

libs/task-commons/src/main/java/org/opensearch/task/commons/clients/TaskWorkerClient.java

@@ -0,0 +1,38 @@
+/*
+ * 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.task.commons.clients;
+
+import org.opensearch.task.commons.task.Task;
+import org.opensearch.task.commons.task.TaskId;
+
+import java.util.List;
+
+/**
+ * Consumer interface used to find new tasks assigned to a {@code WorkerNode} for execution.
+ */
+public interface TaskWorkerClient {
+
+    /**
+     * List all tasks assigned to a WorkerNode.
+     * Useful when the implementation uses a separate store for Task assignments to Worker nodes
+     *
+     * @param taskListRequest TaskListRequest
+     * @return list of all tasks assigned to a WorkerNode
+     */
+    List<Task> getAssignedTasks(TaskListRequest taskListRequest);
+
+    /**
+     * Sends task heart beat to Task Store/Queue
+     *
+     * @param taskId TaskId of Task to send heartbeat for
+     * @param timestamp timestamp of heartbeat to be recorded in TaskStore/Queue
+     */
+    void sendTaskHeartbeat(TaskId taskId, long timestamp);
+
+}

libs/task-commons/src/main/java/org/opensearch/task/commons/clients/package-info.java

@@ -0,0 +1,12 @@
+/*
+ * 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.
+ */
+
+/**
+ * Contains task client related classes
+ */
+package org.opensearch.task.commons.clients;

libs/task-commons/src/main/java/org/opensearch/task/commons/package-info.java

@@ -0,0 +1,12 @@
+/*
+ * 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.
+ */
+
+/**
+ * Contains offline tasks related classes
+ */
+package org.opensearch.task.commons;