add prefix to show the error is from remote service (#1499)

Signed-off-by: Yaliang Wu <[email protected]>

Author: ylwu-amzn

common/src/main/java/org/opensearch/ml/common/CommonValue.java

@@ -18,6 +18,7 @@
 public class CommonValue {
 
     public static Integer NO_SCHEMA_VERSION = 0;
+    public static final String REMOTE_SERVICE_ERROR = "Error from remote service: ";
     public static final String USER = "user";
     public static final String META = "_meta";
     public static final String SCHEMA_VERSION_FIELD = "schema_version";

ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/AwsConnectorExecutor.java

@@ -34,6 +34,7 @@
 import java.util.List;
 import java.util.Map;
 
+import static org.opensearch.ml.common.CommonValue.REMOTE_SERVICE_ERROR;
 import static org.opensearch.ml.common.connector.ConnectorProtocols.AWS_SIGV4;
 import static org.opensearch.ml.engine.algorithms.remote.ConnectorUtils.processOutput;
 import static software.amazon.awssdk.http.SdkHttpMethod.POST;
@@ -102,7 +103,7 @@ public void invokeRemoteModel(MLInput mlInput, Map<String, String> parameters, S
             }
             String modelResponse = responseBuilder.toString();
             if (statusCode < 200 || statusCode >= 300) {
-                throw new OpenSearchStatusException(modelResponse, RestStatus.fromCode(statusCode));
+                throw new OpenSearchStatusException(REMOTE_SERVICE_ERROR + modelResponse, RestStatus.fromCode(statusCode));
             }
 
             ModelTensors tensors = processOutput(modelResponse, connector, scriptService, parameters);

ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/HttpJsonConnectorExecutor.java

@@ -34,6 +34,7 @@
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 
+import static org.opensearch.ml.common.CommonValue.REMOTE_SERVICE_ERROR;
 import static org.opensearch.ml.common.connector.ConnectorProtocols.HTTP;
 import static org.opensearch.ml.engine.algorithms.remote.ConnectorUtils.processOutput;
 
@@ -107,7 +108,7 @@ public void invokeRemoteModel(MLInput mlInput, Map<String, String> parameters, S
             String modelResponse = responseRef.get();
             Integer statusCode = statusCodeRef.get();
             if (statusCode < 200 || statusCode >= 300) {
-                throw new OpenSearchStatusException(modelResponse, RestStatus.fromCode(statusCode));
+                throw new OpenSearchStatusException(REMOTE_SERVICE_ERROR + modelResponse, RestStatus.fromCode(statusCode));
             }
 
             ModelTensors tensors = processOutput(modelResponse, connector, scriptService, parameters);