[GRPC] Add more details for GRPC error responses

CHANGELOG.md

@@ -7,6 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Added
 - Use Lucene `pack` method for `half_float` and `usigned_long` when using `ApproximatePointRangeQuery`.
 - Add a mapper for context aware segments grouping criteria ([#19233](https://github.com/opensearch-project/OpenSearch/pull/19233))
+- Return full error for GRPC error response ([#19568](https://github.com/opensearch-project/OpenSearch/pull/19568))
 
 ### Changed
 - Faster `terms` query creation for `keyword` field with index and docValues enabled ([#19350](https://github.com/opensearch-project/OpenSearch/pull/19350))

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/listeners/SearchRequestActionListener.java

@@ -54,7 +54,7 @@ public void onResponse(SearchResponse response) {
 
     @Override
     public void onFailure(Exception e) {
-        logger.error("SearchRequestActionListener failed to process search request: " + e.getMessage());
+        logger.debug("SearchRequestActionListener failed to process search request: " + e.getMessage());
         StatusRuntimeException grpcError = GrpcErrorHandler.convertToGrpcError(e);
         responseObserver.onError(grpcError);
     }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/services/DocumentServiceImpl.java

@@ -48,7 +48,7 @@ public void bulk(org.opensearch.protobufs.BulkRequest request, StreamObserver<or
             BulkRequestActionListener listener = new BulkRequestActionListener(responseObserver);
             client.bulk(bulkRequest, listener);
         } catch (RuntimeException e) {
-            logger.error("DocumentServiceImpl failed to process bulk request, request=" + request + ", error=" + e.getMessage());
+            logger.debug("DocumentServiceImpl failed: {} - {}", e.getClass().getSimpleName(), e.getMessage());
             StatusRuntimeException grpcError = GrpcErrorHandler.convertToGrpcError(e);
             responseObserver.onError(grpcError);
         }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/services/SearchServiceImpl.java

@@ -67,7 +67,7 @@ public void search(
             SearchRequestActionListener listener = new SearchRequestActionListener(responseObserver);
             client.search(searchRequest, listener);
         } catch (RuntimeException | IOException e) {
-            logger.error("SearchServiceImpl failed to process search request, request=" + request + ", error=" + e.getMessage());
+            logger.debug("SearchServiceImpl failed to process search request, request=" + request + ", error=" + e.getMessage());
             StatusRuntimeException grpcError = GrpcErrorHandler.convertToGrpcError(e);
             responseObserver.onError(grpcError);
         }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/util/GrpcErrorHandler.java

@@ -15,9 +15,12 @@
 import org.apache.logging.log4j.Logger;
 import org.opensearch.ExceptionsHelper;
 import org.opensearch.OpenSearchException;
+import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.compress.NotCompressedException;
 import org.opensearch.core.compress.NotXContentException;
 import org.opensearch.core.concurrency.OpenSearchRejectedExecutionException;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.core.xcontent.XContentBuilder;
 
 import java.io.IOException;
 import java.util.concurrent.TimeoutException;
@@ -26,7 +29,7 @@
 import io.grpc.StatusRuntimeException;
 
 /**
- * Converts exceptions to a GRPC StatusRuntimeException.
+ * Converts exceptions to gRPC StatusRuntimeException with enhanced error details.
  */
 public class GrpcErrorHandler {
     private static final Logger logger = LogManager.getLogger(GrpcErrorHandler.class);
@@ -36,12 +39,12 @@ private GrpcErrorHandler() {
     }
 
     /**
-     * Converts an exception to an appropriate GRPC StatusRuntimeException.
-     * Uses shared constants from {@link ExceptionsHelper.ErrorMessages} and {@link ExceptionsHelper#summaryMessage}
-     * for exact parity with HTTP error handling.
+     * Converts an exception to an appropriate gRPC StatusRuntimeException.
+     * Uses comprehensive exception type mapping for granular gRPC status codes,
+     * with enhanced XContent details for OpenSearchExceptions and full stack traces for debugging.
      *
      * @param e The exception to convert
-     * @return StatusRuntimeException with appropriate GRPC status and HTTP-identical error messages
+     * @return StatusRuntimeException with appropriate gRPC status and enhanced error details
      */
     public static StatusRuntimeException convertToGrpcError(Exception e) {
         // ========== OpenSearch Business Logic Exceptions ==========
@@ -95,22 +98,68 @@ else if (e instanceof IllegalArgumentException) {
     }
 
     /**
-     * Handles OpenSearch-specific exceptions by converting their HTTP status to GRPC status.
-     * Uses {@link ExceptionsHelper#summaryMessage(Throwable)} for exact parity with HTTP error handling.
+     * Handles OpenSearch-specific exceptions using the exact same logic as HTTP error responses.
      *
-     * Uses {@link ExceptionsHelper#unwrapToOpenSearchException(Throwable)} for shared unwrapping logic
-     * with HTTP's {@link OpenSearchException#generateFailureXContent}.
+     * Equivalent to: {@code BytesRestResponse.build()} and {@code OpenSearchException.generateThrowableXContent()}
+     * in HTTP REST handling.
      *
-     * @param e The {@link OpenSearchException} to convert
-     * @return StatusRuntimeException with mapped GRPC status and HTTP-identical error message
+     * @param ose The OpenSearchException to convert
+     * @return StatusRuntimeException with mapped gRPC status and HTTP-identical error message
      */
-    private static StatusRuntimeException handleOpenSearchException(OpenSearchException e) {
-        Status grpcStatus = RestToGrpcStatusConverter.convertRestToGrpcStatus(e.status());
+    private static StatusRuntimeException handleOpenSearchException(OpenSearchException ose) {
+        Status grpcStatus = RestToGrpcStatusConverter.convertRestToGrpcStatus(ose.status());
 
-        Throwable unwrapped = ExceptionsHelper.unwrapToOpenSearchException(e);
+        // Use existing HTTP logic but enhance description with metadata from XContent
+        Throwable unwrapped = ExceptionsHelper.unwrapToOpenSearchException(ose);
+        String baseDescription = ExceptionsHelper.summaryMessage(unwrapped);
 
-        String description = ExceptionsHelper.summaryMessage(unwrapped);
-        return grpcStatus.withDescription(description).asRuntimeException();
+        // Extract metadata using the same XContent infrastructure as HTTP
+        String enhancedDescription = enhanceDescriptionWithXContentMetadata(unwrapped, baseDescription);
+
+        return grpcStatus.withDescription(enhancedDescription).asRuntimeException();
     }
 
+    /**
+     * Enhances error description using the exact same XContent infrastructure as HTTP responses.
+     * This ensures perfect consistency by reusing the identical serialization logic.
+     *
+     * Equivalent to: {@code OpenSearchException.generateThrowableXContent()} used by HTTP error responses.
+     *
+     * @param exception The exception to extract metadata from
+     * @param baseDescription The base description from ExceptionsHelper.summaryMessage()
+     * @return Enhanced description with full JSON metadata from XContent
+     */
+    private static String enhanceDescriptionWithXContentMetadata(Throwable exception, String baseDescription) {
+        try {
+            // Use the exact same method as HTTP error responses
+            try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
+                // Wrap in object like HTTP does in BytesRestResponse.build()
+                builder.startObject();
+
+                // Use the same method as HTTP REST responses (BytesRestResponse.build)
+                // This includes root_cause analysis, just like HTTP
+                OpenSearchException.generateFailureXContent(builder, ToXContent.EMPTY_PARAMS, (Exception) exception, true);
+
+                // Add status field like HTTP does
+                org.opensearch.core.rest.RestStatus restStatus = ExceptionsHelper.status((Exception) exception);
+                builder.field("status", restStatus.getStatus());
+
+                builder.endObject();
+
+                // Get the full JSON structure - identical to HTTP error responses
+                String jsonString = builder.toString();
+
+                // Log the full JSON for debugging at DEBUG level
+                logger.debug("gRPC error details: {}", jsonString);
+
+                // Return the base description with full JSON details
+                return baseDescription + "; details=" + jsonString;
+            }
+
+        } catch (Exception e) {
+            // If XContent extraction fails, log and return base description
+            logger.error("Failed to extract XContent metadata for exception: " + e.getMessage());
+            return baseDescription;
+        }
+    }
 }