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Signed-off-by: Louis Chu <clingzhi@amazon.com>

async-query/src/main/java/org/opensearch/sql/spark/scheduler/OpenSearchAsyncQueryScheduler.java

@@ -41,6 +41,7 @@
 import org.opensearch.sql.spark.scheduler.model.OpenSearchRefreshIndexJobRequest;
 import org.opensearch.threadpool.ThreadPool;
 
+/** Scheduler class for managing asynchronous query jobs. */
 public class OpenSearchAsyncQueryScheduler {
   public static final String SCHEDULER_INDEX_NAME = ".async-query-scheduler";
   public static final String SCHEDULER_PLUGIN_JOB_TYPE = "async-query-scheduler";
@@ -52,6 +53,7 @@ public class OpenSearchAsyncQueryScheduler {
   private Client client;
   private ClusterService clusterService;
 
+  /** Loads job resources, setting up required services and job runner instance. */
   public void loadJobResource(Client client, ClusterService clusterService, ThreadPool threadPool) {
     this.client = client;
     this.clusterService = clusterService;
@@ -62,6 +64,7 @@ public void loadJobResource(Client client, ClusterService clusterService, Thread
     openSearchRefreshIndexJob.setClient(client);
   }
 
+  /** Schedules a new job by indexing it into the job index. */
   public void scheduleJob(OpenSearchRefreshIndexJobRequest request) {
     if (!this.clusterService.state().routingTable().hasIndex(SCHEDULER_INDEX_NAME)) {
       createAsyncQuerySchedulerIndex();
@@ -90,6 +93,7 @@ public void scheduleJob(OpenSearchRefreshIndexJobRequest request) {
     }
   }
 
+  /** Unschedules a job by marking it as disabled and updating its last update time. */
   public void unscheduleJob(String jobId) throws IOException {
     if (!this.clusterService.state().routingTable().hasIndex(SCHEDULER_INDEX_NAME)) {
       throw new IllegalArgumentException("Job index does not exist.");
@@ -103,6 +107,7 @@ public void unscheduleJob(String jobId) throws IOException {
     updateJob(request);
   }
 
+  /** Updates an existing job with new parameters. */
   public void updateJob(OpenSearchRefreshIndexJobRequest request) throws IOException {
     if (!this.clusterService.state().routingTable().hasIndex(SCHEDULER_INDEX_NAME)) {
       throw new IllegalArgumentException("Job index does not exist.");
@@ -123,6 +128,7 @@ public void updateJob(OpenSearchRefreshIndexJobRequest request) throws IOExcepti
     }
   }
 
+  /** Removes a job by deleting its document from the index. */
   public void removeJob(String jobId) {
     if (!this.clusterService.state().routingTable().hasIndex(SCHEDULER_INDEX_NAME)) {
       throw new IllegalArgumentException("Job index does not exist.");
@@ -142,6 +148,7 @@ public void removeJob(String jobId) {
     }
   }
 
+  /** Creates the async query scheduler index with specified mappings and settings. */
   private void createAsyncQuerySchedulerIndex() {
     try {
       InputStream mappingFileStream =
@@ -177,10 +184,12 @@ private void createAsyncQuerySchedulerIndex() {
     }
   }
 
+  /** Returns the job runner instance for the scheduler. */
   public static ScheduledJobRunner getJobRunner() {
     return OpenSearchRefreshIndexJob.getJobRunnerInstance();
   }
 
+  /** Returns the job parser instance for the scheduler. */
   public static ScheduledJobParser getJobParser() {
     return (parser, id, jobDocVersion) -> {
       OpenSearchRefreshIndexJobRequest.OpenSearchRefreshIndexJobRequestBuilder builder =

async-query/src/main/java/org/opensearch/sql/spark/scheduler/exceptions/AsyncQuerySchedulerException.java

@@ -7,6 +7,7 @@
 
 package org.opensearch.sql.spark.scheduler.exceptions;
 
+/** Exception class for handling errors related to the asynchronous query scheduler. */
 public class AsyncQuerySchedulerException extends RuntimeException {
   public AsyncQuerySchedulerException(String message) {
     super(message);