Resolved the comments

Signed-off-by: Rai <nndri@amazon.com>

Author: Rai

server/src/main/java/org/opensearch/action/ingest/SimulateExecutionService.java

@@ -91,7 +91,6 @@ void executeDocument(
     }
 
     public void execute(SimulatePipelineRequest.Parsed request, ActionListener<SimulatePipelineResponse> listener) {
-
         threadPool.executor(THREAD_POOL_NAME).execute(ActionRunnable.wrap(listener, l -> {
             final AtomicInteger counter = new AtomicInteger();
             final List<SimulateDocumentResult> responses = new CopyOnWriteArrayList<>(

server/src/main/java/org/opensearch/action/ingest/SimulatePipelineTransportAction.java

@@ -38,7 +38,6 @@
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.io.stream.Writeable;
-import org.opensearch.ingest.IngestPipelineValidator;
 import org.opensearch.ingest.IngestService;
 import org.opensearch.tasks.Task;
 import org.opensearch.threadpool.ThreadPool;
@@ -89,7 +88,7 @@ protected void doExecute(Task task, SimulatePipelineRequest request, ActionListe
             return;
         }
 
-        IngestPipelineValidator.validateIngestPipeline(simulateRequest.getPipeline(), ingestService.getClusterService());
+        ingestService.validateProcessorCountForIngestPipeline(simulateRequest.getPipeline());
 
         executionService.execute(simulateRequest, listener);
     }

server/src/main/java/org/opensearch/common/settings/ClusterSettings.java

@@ -132,7 +132,7 @@
 import org.opensearch.indices.fielddata.cache.IndicesFieldDataCache;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.store.IndicesStore;
-import org.opensearch.ingest.IngestPipelineValidator;
+import org.opensearch.ingest.IngestService;
 import org.opensearch.monitor.fs.FsHealthService;
 import org.opensearch.monitor.fs.FsService;
 import org.opensearch.monitor.jvm.JvmGcMonitorService;
@@ -406,7 +406,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                 ClusterService.USER_DEFINED_METADATA,
                 ClusterManagerService.MASTER_SERVICE_SLOW_TASK_LOGGING_THRESHOLD_SETTING,  // deprecated
                 ClusterManagerService.CLUSTER_MANAGER_SERVICE_SLOW_TASK_LOGGING_THRESHOLD_SETTING,
-                IngestPipelineValidator.MAX_NUMBER_OF_INGEST_PROCESSORS,
+                IngestService.MAX_NUMBER_OF_INGEST_PROCESSORS,
                 SearchService.DEFAULT_SEARCH_TIMEOUT_SETTING,
                 SearchService.DEFAULT_ALLOW_PARTIAL_SEARCH_RESULTS,
                 TransportSearchAction.SHARD_COUNT_LIMIT_SETTING,

server/src/main/java/org/opensearch/ingest/IngestPipelineValidator.java

@@ -62,6 +62,7 @@
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.metrics.OperationMetrics;
 import org.opensearch.common.regex.Regex;
+import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.concurrent.AbstractRunnable;
@@ -107,6 +108,18 @@ public class IngestService implements ClusterStateApplier, ReportingService<Inge
 
     public static final String INGEST_ORIGIN = "ingest";
 
+    /**
+     * Defines the limit for the number of processors which can run on a given document during ingestion.
+     */
+    public static final Setting<Integer> MAX_NUMBER_OF_INGEST_PROCESSORS = Setting.intSetting(
+        "cluster.ingest.max_number_processors",
+        Integer.MAX_VALUE,
+        1,
+        Integer.MAX_VALUE,
+        Setting.Property.NodeScope,
+        Setting.Property.Dynamic
+    );
+
     private static final Logger logger = LogManager.getLogger(IngestService.class);
 
     private final ClusterService clusterService;
@@ -123,6 +136,7 @@ public class IngestService implements ClusterStateApplier, ReportingService<Inge
     private final ClusterManagerTaskThrottler.ThrottlingKey putPipelineTaskKey;
     private final ClusterManagerTaskThrottler.ThrottlingKey deletePipelineTaskKey;
     private volatile ClusterState state;
+    private volatile int maxIngestProcessorCount;
 
     public IngestService(
         ClusterService clusterService,
@@ -156,6 +170,12 @@ public IngestService(
         // Task is onboarded for throttling, it will get retried from associated TransportClusterManagerNodeAction.
         putPipelineTaskKey = clusterService.registerClusterManagerTask(ClusterManagerTaskKeys.PUT_PIPELINE_KEY, true);
         deletePipelineTaskKey = clusterService.registerClusterManagerTask(ClusterManagerTaskKeys.DELETE_PIPELINE_KEY, true);
+        clusterService.getClusterSettings().addSettingsUpdateConsumer(MAX_NUMBER_OF_INGEST_PROCESSORS, this::setMaxIngestProcessorCount);
+        setMaxIngestProcessorCount(clusterService.getClusterSettings().get(MAX_NUMBER_OF_INGEST_PROCESSORS));
+    }
+
+    private void setMaxIngestProcessorCount(Integer maxIngestProcessorCount) {
+        this.maxIngestProcessorCount = maxIngestProcessorCount;
     }
 
     private static Map<String, Processor.Factory> processorFactories(List<IngestPlugin> ingestPlugins, Processor.Parameters parameters) {
@@ -495,7 +515,7 @@ void validatePipeline(Map<DiscoveryNode, IngestInfo> ingestInfos, PutPipelineReq
         Map<String, Object> pipelineConfig = XContentHelper.convertToMap(request.getSource(), false, request.getMediaType()).v2();
         Pipeline pipeline = Pipeline.create(request.getId(), pipelineConfig, processorFactories, scriptService);
 
-        IngestPipelineValidator.validateIngestPipeline(pipeline, clusterService);
+        validateProcessorCountForIngestPipeline(pipeline);
 
         List<Exception> exceptions = new ArrayList<>();
         for (Processor processor : pipeline.flattenAllProcessors()) {
@@ -510,6 +530,20 @@ void validatePipeline(Map<DiscoveryNode, IngestInfo> ingestInfos, PutPipelineReq
         ExceptionsHelper.rethrowAndSuppress(exceptions);
     }
 
+    public void validateProcessorCountForIngestPipeline(Pipeline pipeline) {
+        List<Processor> processors = pipeline.getCompoundProcessor().getProcessors();
+
+        if (processors.size() > maxIngestProcessorCount) {
+            throw new IllegalStateException(
+                "Cannot use more than the maximum processors allowed. Number of processors being configured is ["
+                    + processors.size()
+                    + "] which exceeds the maximum allowed configuration of ["
+                    + maxIngestProcessorCount
+                    + "] processors."
+            );
+        }
+    }
+
     public void executeBulkRequest(
         int numberOfActionRequests,
         Iterable<DocWriteRequest<?>> actionRequests,
@@ -1102,7 +1136,6 @@ void innerUpdatePipelines(IngestMetadata newIngestMetadata) {
                     processorFactories,
                     scriptService
                 );
-                IngestPipelineValidator.validateIngestPipeline(newPipeline, clusterService);
                 newPipelines.put(newConfiguration.getId(), new PipelineHolder(newConfiguration, newPipeline));
 
                 if (previous == null) {

server/src/main/java/org/opensearch/ingest/IngestService.java

@@ -10,7 +10,6 @@
 
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.ingest.IngestPipelineValidator;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.threadpool.TestThreadPool;
 import org.junit.After;
@@ -38,16 +37,4 @@ public void testDeprecatedGetMasterServiceBWC() {
             assertThat(masterService, equalTo(clusterManagerService));
         }
     }
-
-    public void testUpdateMaxIngestProcessorCountSetting() {
-        ClusterSettings clusterSettings = new ClusterSettings(Settings.builder().build(), ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
-
-        // verify defaults
-        assertEquals(Integer.MAX_VALUE, clusterSettings.get(IngestPipelineValidator.MAX_NUMBER_OF_INGEST_PROCESSORS).intValue());
-
-        // verify update max processor
-        Settings newSettings = Settings.builder().put("cluster.ingest.max_number_processors", 3).build();
-        clusterSettings.applySettings(newSettings);
-        assertEquals(3, clusterSettings.get(IngestPipelineValidator.MAX_NUMBER_OF_INGEST_PROCESSORS).intValue());
-    }
 }

server/src/test/java/org/opensearch/cluster/service/ClusterServiceTests.java

@@ -58,6 +58,7 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.SetOnce;
 import org.opensearch.common.metrics.OperationStats;
+import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.OpenSearchExecutors;
 import org.opensearch.common.xcontent.XContentType;
@@ -2058,6 +2059,18 @@ public void testPrepareBatches_different_index_pipeline() {
         assertEquals(4, batches.size());
     }
 
+    public void testUpdateMaxIngestProcessorCountSetting() {
+        ClusterSettings clusterSettings = new ClusterSettings(Settings.builder().build(), ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+
+        // verify defaults
+        assertEquals(Integer.MAX_VALUE, clusterSettings.get(IngestService.MAX_NUMBER_OF_INGEST_PROCESSORS).intValue());
+
+        // verify update max processor
+        Settings newSettings = Settings.builder().put("cluster.ingest.max_number_processors", 3).build();
+        clusterSettings.applySettings(newSettings);
+        assertEquals(3, clusterSettings.get(IngestService.MAX_NUMBER_OF_INGEST_PROCESSORS).intValue());
+    }
+
     private IngestService.IndexRequestWrapper createIndexRequestWrapper(String index, List<String> pipelines) {
         IndexRequest indexRequest = new IndexRequest(index);
         return new IngestService.IndexRequestWrapper(0, indexRequest, pipelines, true);