[Backport 2.x] Adds transport request retry capability for GetMLTaskS…

…tep (#193)

src/main/java/org/opensearch/flowframework/FlowFrameworkPlugin.java

@@ -60,6 +60,7 @@
 import static org.opensearch.flowframework.common.CommonValue.FLOW_FRAMEWORK_THREAD_POOL_PREFIX;
 import static org.opensearch.flowframework.common.CommonValue.PROVISION_THREAD_POOL;
 import static org.opensearch.flowframework.common.FlowFrameworkSettings.FLOW_FRAMEWORK_ENABLED;
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_GET_TASK_REQUEST_RETRY;
 import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_WORKFLOWS;
 import static org.opensearch.flowframework.common.FlowFrameworkSettings.WORKFLOW_REQUEST_TIMEOUT;
 
@@ -69,6 +70,7 @@
 public class FlowFrameworkPlugin extends Plugin implements ActionPlugin {
 
     private FlowFrameworkFeatureEnabledSetting flowFrameworkFeatureEnabledSetting;
+
     private ClusterService clusterService;
 
     /**
@@ -93,10 +95,15 @@ public Collection<Object> createComponents(
         Settings settings = environment.settings();
         this.clusterService = clusterService;
         flowFrameworkFeatureEnabledSetting = new FlowFrameworkFeatureEnabledSetting(clusterService, settings);
-
         MachineLearningNodeClient mlClient = new MachineLearningNodeClient(client);
         FlowFrameworkIndicesHandler flowFrameworkIndicesHandler = new FlowFrameworkIndicesHandler(client, clusterService);
-        WorkflowStepFactory workflowStepFactory = new WorkflowStepFactory(clusterService, client, mlClient, flowFrameworkIndicesHandler);
+        WorkflowStepFactory workflowStepFactory = new WorkflowStepFactory(
+            settings,
+            clusterService,
+            client,
+            mlClient,
+            flowFrameworkIndicesHandler
+        );
         WorkflowProcessSorter workflowProcessSorter = new WorkflowProcessSorter(workflowStepFactory, threadPool);
 
         return ImmutableList.of(workflowStepFactory, workflowProcessSorter, flowFrameworkIndicesHandler);
@@ -132,7 +139,12 @@ public List<RestHandler> getRestHandlers(
 
     @Override
     public List<Setting<?>> getSettings() {
-        List<Setting<?>> settings = ImmutableList.of(FLOW_FRAMEWORK_ENABLED, MAX_WORKFLOWS, WORKFLOW_REQUEST_TIMEOUT);
+        List<Setting<?>> settings = ImmutableList.of(
+            FLOW_FRAMEWORK_ENABLED,
+            MAX_WORKFLOWS,
+            WORKFLOW_REQUEST_TIMEOUT,
+            MAX_GET_TASK_REQUEST_RETRY
+        );
         return settings;
     }
 

src/main/java/org/opensearch/flowframework/common/FlowFrameworkSettings.java

@@ -44,4 +44,13 @@ private FlowFrameworkSettings() {}
         Setting.Property.NodeScope,
         Setting.Property.Dynamic
     );
+
+    /** This setting sets the maximum number of get task request retries */
+    public static final Setting<Integer> MAX_GET_TASK_REQUEST_RETRY = Setting.intSetting(
+        "plugins.flow_framework.max_get_task_request_retry",
+        5,
+        0,
+        Setting.Property.NodeScope,
+        Setting.Property.Dynamic
+    );
 }

src/main/java/org/opensearch/flowframework/transport/GetWorkflowResponse.java

@@ -22,7 +22,9 @@
  */
 public class GetWorkflowResponse extends ActionResponse implements ToXContentObject {
 
+    /** The workflow state */
     public WorkflowState workflowState;
+    /** Flag to indicate if the entire state should be returned */
     public boolean allStatus;
 
     /**

src/main/java/org/opensearch/flowframework/workflow/AbstractRetryableWorkflowStep.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright OpenSearch Contributors
+ * 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.flowframework.workflow;
+
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.Settings;
+
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_GET_TASK_REQUEST_RETRY;
+
+/**
+ * Abstract retryable workflow step
+ */
+public abstract class AbstractRetryableWorkflowStep implements WorkflowStep {
+
+    /** The maximum number of transport request retries */
+    protected volatile Integer maxRetry;
+
+    /**
+     * Instantiates a new Retryable workflow step
+     * @param settings Environment settings
+     * @param clusterService the cluster service
+     */
+    public AbstractRetryableWorkflowStep(Settings settings, ClusterService clusterService) {
+        this.maxRetry = MAX_GET_TASK_REQUEST_RETRY.get(settings);
+        clusterService.getClusterSettings().addSettingsUpdateConsumer(MAX_GET_TASK_REQUEST_RETRY, it -> maxRetry = it);
+    }
+
+}

src/main/java/org/opensearch/flowframework/workflow/GetMLTaskStep.java

@@ -11,11 +11,14 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.concurrent.FutureUtils;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.flowframework.exception.FlowFrameworkException;
 import org.opensearch.ml.client.MachineLearningNodeClient;
-import org.opensearch.ml.common.MLTask;
+import org.opensearch.ml.common.MLTaskState;
 
 import java.util.List;
 import java.util.Map;
@@ -29,17 +32,20 @@
 /**
  * Step to retrieve an ML Task
  */
-public class GetMLTaskStep implements WorkflowStep {
+public class GetMLTaskStep extends AbstractRetryableWorkflowStep {
 
     private static final Logger logger = LogManager.getLogger(GetMLTaskStep.class);
     private MachineLearningNodeClient mlClient;
     static final String NAME = "get_ml_task";
 
     /**
      * Instantiate this class
+     * @param settings the Opensearch settings
+     * @param clusterService the OpenSearch cluster service
      * @param mlClient client to instantiate MLClient
      */
-    public GetMLTaskStep(MachineLearningNodeClient mlClient) {
+    public GetMLTaskStep(Settings settings, ClusterService clusterService, MachineLearningNodeClient mlClient) {
+        super(settings, clusterService);
         this.mlClient = mlClient;
     }
 
@@ -48,23 +54,6 @@ public CompletableFuture<WorkflowData> execute(List<WorkflowData> data) {
 
         CompletableFuture<WorkflowData> getMLTaskFuture = new CompletableFuture<>();
 
-        ActionListener<MLTask> actionListener = ActionListener.wrap(response -> {
-
-            // TODO : Add retry capability if response status is not COMPLETED :
-            // https://github.com/opensearch-project/flow-framework/issues/158
-
-            logger.info("ML Task retrieval successful");
-            getMLTaskFuture.complete(
-                new WorkflowData(
-                    Map.ofEntries(Map.entry(MODEL_ID, response.getModelId()), Map.entry(REGISTER_MODEL_STATUS, response.getState().name())),
-                    data.get(0).getWorkflowId()
-                )
-            );
-        }, exception -> {
-            logger.error("Failed to retrieve ML Task");
-            getMLTaskFuture.completeExceptionally(new FlowFrameworkException(exception.getMessage(), ExceptionsHelper.status(exception)));
-        });
-
         String taskId = null;
 
         for (WorkflowData workflowData : data) {
@@ -84,7 +73,7 @@ public CompletableFuture<WorkflowData> execute(List<WorkflowData> data) {
             logger.error("Failed to retrieve ML Task");
             getMLTaskFuture.completeExceptionally(new FlowFrameworkException("Required fields are not provided", RestStatus.BAD_REQUEST));
         } else {
-            mlClient.getTask(taskId, actionListener);
+            retryableGetMlTask(data.get(0).getWorkflowId(), getMLTaskFuture, taskId, 0);
         }
 
         return getMLTaskFuture;
@@ -95,4 +84,46 @@ public String getName() {
         return NAME;
     }
 
+    /**
+     * Retryable GetMLTask
+     * @param workflowId the workflow id
+     * @param getMLTaskFuture the workflow step future
+     * @param taskId the ml task id
+     * @param retries the current number of request retries
+     */
+    protected void retryableGetMlTask(String workflowId, CompletableFuture<WorkflowData> getMLTaskFuture, String taskId, int retries) {
+        mlClient.getTask(taskId, ActionListener.wrap(response -> {
+            if (response.getState() != MLTaskState.COMPLETED) {
+                throw new IllegalStateException("MLTask is not yet completed");
+            } else {
+                logger.info("ML Task retrieval successful");
+                getMLTaskFuture.complete(
+                    new WorkflowData(
+                        Map.ofEntries(
+                            Map.entry(MODEL_ID, response.getModelId()),
+                            Map.entry(REGISTER_MODEL_STATUS, response.getState().name())
+                        ),
+                        workflowId
+                    )
+                );
+            }
+        }, exception -> {
+            if (retries < maxRetry) {
+                // Sleep thread prior to retrying request
+                try {
+                    Thread.sleep(5000);
+                } catch (Exception e) {
+                    FutureUtils.cancel(getMLTaskFuture);
+                }
+                final int retryAdd = retries + 1;
+                retryableGetMlTask(workflowId, getMLTaskFuture, taskId, retryAdd);
+            } else {
+                logger.error("Failed to retrieve ML Task, maximum retries exceeded");
+                getMLTaskFuture.completeExceptionally(
+                    new FlowFrameworkException(exception.getMessage(), ExceptionsHelper.status(exception))
+                );
+            }
+        }));
+    }
+
 }

src/main/java/org/opensearch/flowframework/workflow/WorkflowStepFactory.java

@@ -10,6 +10,7 @@
 
 import org.opensearch.client.Client;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.flowframework.exception.FlowFrameworkException;
 import org.opensearch.flowframework.indices.FlowFrameworkIndicesHandler;
@@ -29,22 +30,25 @@ public class WorkflowStepFactory {
     /**
      * Instantiate this class.
      *
+     * @param settings The OpenSearch settings
      * @param clusterService The OpenSearch cluster service
      * @param client The OpenSearch client steps can use
      * @param mlClient Machine Learning client to perform ml operations
      * @param flowFrameworkIndicesHandler FlowFrameworkIndicesHandler class to update system indices
      */
     public WorkflowStepFactory(
+        Settings settings,
         ClusterService clusterService,
         Client client,
         MachineLearningNodeClient mlClient,
         FlowFrameworkIndicesHandler flowFrameworkIndicesHandler
     ) {
         this.flowFrameworkIndicesHandler = flowFrameworkIndicesHandler;
-        populateMap(clusterService, client, mlClient, flowFrameworkIndicesHandler);
+        populateMap(settings, clusterService, client, mlClient, flowFrameworkIndicesHandler);
     }
 
     private void populateMap(
+        Settings settings,
         ClusterService clusterService,
         Client client,
         MachineLearningNodeClient mlClient,
@@ -58,7 +62,7 @@ private void populateMap(
         stepMap.put(DeployModelStep.NAME, new DeployModelStep(mlClient));
         stepMap.put(CreateConnectorStep.NAME, new CreateConnectorStep(mlClient, flowFrameworkIndicesHandler));
         stepMap.put(ModelGroupStep.NAME, new ModelGroupStep(mlClient));
-        stepMap.put(GetMLTaskStep.NAME, new GetMLTaskStep(mlClient));
+        stepMap.put(GetMLTaskStep.NAME, new GetMLTaskStep(settings, clusterService, mlClient));
     }
 
     /**

src/test/java/org/opensearch/flowframework/FlowFrameworkPluginTests.java

@@ -27,6 +27,7 @@
 import java.util.stream.Stream;
 
 import static org.opensearch.flowframework.common.FlowFrameworkSettings.FLOW_FRAMEWORK_ENABLED;
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_GET_TASK_REQUEST_RETRY;
 import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_WORKFLOWS;
 import static org.opensearch.flowframework.common.FlowFrameworkSettings.WORKFLOW_REQUEST_TIMEOUT;
 import static org.mockito.Mockito.mock;
@@ -61,7 +62,7 @@ public void setUp() throws Exception {
 
         final Set<Setting<?>> settingsSet = Stream.concat(
             ClusterSettings.BUILT_IN_CLUSTER_SETTINGS.stream(),
-            Stream.of(FLOW_FRAMEWORK_ENABLED, MAX_WORKFLOWS, WORKFLOW_REQUEST_TIMEOUT)
+            Stream.of(FLOW_FRAMEWORK_ENABLED, MAX_WORKFLOWS, WORKFLOW_REQUEST_TIMEOUT, MAX_GET_TASK_REQUEST_RETRY)
         ).collect(Collectors.toSet());
         clusterSettings = new ClusterSettings(settings, settingsSet);
         clusterService = mock(ClusterService.class);
@@ -83,7 +84,7 @@ public void testPlugin() throws IOException {
             assertEquals(4, ffp.getRestHandlers(settings, null, null, null, null, null, null).size());
             assertEquals(4, ffp.getActions().size());
             assertEquals(1, ffp.getExecutorBuilders(settings).size());
-            assertEquals(3, ffp.getSettings().size());
+            assertEquals(4, ffp.getSettings().size());
         }
     }
 }

src/test/java/org/opensearch/flowframework/model/WorkflowValidatorTests.java

@@ -12,6 +12,9 @@
 import org.opensearch.client.Client;
 import org.opensearch.client.ClusterAdminClient;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.flowframework.indices.FlowFrameworkIndicesHandler;
 import org.opensearch.flowframework.workflow.WorkflowStepFactory;
@@ -21,7 +24,14 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
-
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.FLOW_FRAMEWORK_ENABLED;
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_GET_TASK_REQUEST_RETRY;
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.MAX_WORKFLOWS;
+import static org.opensearch.flowframework.common.FlowFrameworkSettings.WORKFLOW_REQUEST_TIMEOUT;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -70,7 +80,20 @@ public void testWorkflowStepFactoryHasValidators() throws IOException {
         MachineLearningNodeClient mlClient = mock(MachineLearningNodeClient.class);
         FlowFrameworkIndicesHandler flowFrameworkIndicesHandler = mock(FlowFrameworkIndicesHandler.class);
 
-        WorkflowStepFactory workflowStepFactory = new WorkflowStepFactory(clusterService, client, mlClient, flowFrameworkIndicesHandler);
+        final Set<Setting<?>> settingsSet = Stream.concat(
+            ClusterSettings.BUILT_IN_CLUSTER_SETTINGS.stream(),
+            Stream.of(FLOW_FRAMEWORK_ENABLED, MAX_WORKFLOWS, WORKFLOW_REQUEST_TIMEOUT, MAX_GET_TASK_REQUEST_RETRY)
+        ).collect(Collectors.toSet());
+        ClusterSettings clusterSettings = new ClusterSettings(Settings.EMPTY, settingsSet);
+        when(clusterService.getClusterSettings()).thenReturn(clusterSettings);
+
+        WorkflowStepFactory workflowStepFactory = new WorkflowStepFactory(
+            Settings.EMPTY,
+            clusterService,
+            client,
+            mlClient,
+            flowFrameworkIndicesHandler
+        );
 
         // Read in workflow-steps.json
         WorkflowValidator workflowValidator = WorkflowValidator.parse("mappings/workflow-steps.json");