fix: retry specific internal errors

google-cloud-spanner/src/main/java/com/google/cloud/spanner/IsRetryableInternalError.java

@@ -18,33 +18,35 @@
 
 import com.google.api.gax.rpc.InternalException;
 import com.google.common.base.Predicate;
+import com.google.common.collect.ImmutableList;
 import io.grpc.Status;
+import io.grpc.Status.Code;
 import io.grpc.StatusRuntimeException;
 
 public class IsRetryableInternalError implements Predicate<Throwable> {
+  public static final IsRetryableInternalError INSTANCE = new IsRetryableInternalError();
 
-  private static final String HTTP2_ERROR_MESSAGE = "HTTP/2 error code: INTERNAL_ERROR";
-  private static final String CONNECTION_CLOSED_ERROR_MESSAGE =
-      "Connection closed with unknown cause";
-  private static final String EOS_ERROR_MESSAGE =
-      "Received unexpected EOS on DATA frame from server";
+  private static final ImmutableList<String> RETRYABLE_ERROR_MESSAGES =
+      ImmutableList.of(
+          "HTTP/2 error code: INTERNAL_ERROR",
+          "Connection closed with unknown cause",
+          "Received unexpected EOS on DATA frame from server",
+          "stream terminated by RST_STREAM",
+          "Authentication backend internal server error. Please retry.");
 
-  private static final String RST_STREAM_ERROR_MESSAGE = "stream terminated by RST_STREAM";
+  public boolean isRetryableInternalError(Status status) {
+    return status.getCode() == Code.INTERNAL
+        && status.getDescription() != null
+        && isRetryableErrorMessage(status.getDescription());
+  }
 
   @Override
   public boolean apply(Throwable cause) {
-    if (isInternalError(cause)) {
-      if (cause.getMessage().contains(HTTP2_ERROR_MESSAGE)) {
-        return true;
-      } else if (cause.getMessage().contains(CONNECTION_CLOSED_ERROR_MESSAGE)) {
-        return true;
-      } else if (cause.getMessage().contains(EOS_ERROR_MESSAGE)) {
-        return true;
-      } else if (cause.getMessage().contains(RST_STREAM_ERROR_MESSAGE)) {
-        return true;
-      }
-    }
-    return false;
+    return isInternalError(cause) && isRetryableErrorMessage(cause.getMessage());
+  }
+
+  private boolean isRetryableErrorMessage(String errorMessage) {
+    return RETRYABLE_ERROR_MESSAGES.stream().anyMatch(errorMessage::contains);
   }
 
   private boolean isInternalError(Throwable cause) {

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerErrorInterceptor.java

@@ -16,6 +16,7 @@
 
 package com.google.cloud.spanner.spi.v1;
 
+import com.google.cloud.spanner.IsRetryableInternalError;
 import com.google.rpc.BadRequest;
 import com.google.rpc.Help;
 import com.google.rpc.LocalizedMessage;
@@ -32,6 +33,7 @@
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
 import io.grpc.Status;
+import io.grpc.Status.Code;
 import io.grpc.protobuf.ProtoUtils;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -69,6 +71,12 @@ public void start(Listener<RespT> responseListener, Metadata headers) {
               @Override
               public void onClose(Status status, Metadata trailers) {
                 try {
+                  // Translate INTERNAL errors that should be retried to a retryable error code.
+                  if (status.getCode() == Code.INTERNAL
+                      && IsRetryableInternalError.INSTANCE.isRetryableInternalError(status)) {
+                    status =
+                        Status.fromCode(Code.UNAVAILABLE).withDescription(status.getDescription());
+                  }
                   if (trailers.containsKey(LOCALIZED_MESSAGE_KEY)) {
                     status =
                         Status.fromCodeValue(status.getCode().value())

google-cloud-spanner/src/test/java/com/google/cloud/spanner/IsRetryableInternalErrorTest.java

@@ -127,6 +127,17 @@ public void rstStreamInternalExceptionIsRetryable() {
     assertTrue(predicate.apply(e));
   }
 
+  @Test
+  public void testAuthenticationBackendInternalServerErrorIsRetryable() {
+    final StatusRuntimeException exception =
+        new StatusRuntimeException(
+            Status.fromCode(Code.INTERNAL)
+                .withDescription(
+                    "INTERNAL: Authentication backend internal server error. Please retry."));
+
+    assertTrue(predicate.apply(exception));
+  }
+
   @Test
   public void genericInternalExceptionIsNotRetryable() {
     final InternalException e =

google-cloud-spanner/src/test/java/com/google/cloud/spanner/RetryableInternalErrorTest.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.spanner;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import com.google.cloud.NoCredentials;
+import com.google.cloud.spanner.MockSpannerServiceImpl.SimulatedExecutionTime;
+import com.google.cloud.spanner.connection.AbstractMockServerTest;
+import com.google.spanner.v1.BatchCreateSessionsRequest;
+import com.google.spanner.v1.ExecuteSqlRequest;
+import io.grpc.ManagedChannelBuilder;
+import io.grpc.Status;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class RetryableInternalErrorTest extends AbstractMockServerTest {
+  @Test
+  public void testTranslateInternalException() {
+    try (Spanner spanner =
+        SpannerOptions.newBuilder()
+            .setProjectId("my-project")
+            .setHost(String.format("http://localhost:%d", getPort()))
+            .setChannelConfigurator(ManagedChannelBuilder::usePlaintext)
+            .setCredentials(NoCredentials.getInstance())
+            .setSessionPoolOption(
+                SessionPoolOptions.newBuilder().setMinSessions(1).setMaxSessions(1).build())
+            .build()
+            .getService()) {
+      DatabaseClient client = spanner.getDatabaseClient(DatabaseId.of("p", "i", "d"));
+      mockSpanner.setBatchCreateSessionsExecutionTime(
+          SimulatedExecutionTime.ofException(
+              Status.INTERNAL
+                  .withDescription("Authentication backend internal server error. Please retry.")
+                  .asRuntimeException()));
+      mockSpanner.setExecuteStreamingSqlExecutionTime(
+          SimulatedExecutionTime.ofException(
+              Status.INTERNAL
+                  .withDescription("Authentication backend internal server error. Please retry.")
+                  .asRuntimeException()));
+      mockSpanner.setExecuteSqlExecutionTime(
+          SimulatedExecutionTime.ofException(
+              Status.INTERNAL
+                  .withDescription("Authentication backend internal server error. Please retry.")
+                  .asRuntimeException()));
+
+      try (ResultSet resultSet = client.singleUse().executeQuery(SELECT1_STATEMENT)) {
+        assertTrue(resultSet.next());
+        assertFalse(resultSet.next());
+      }
+      assertEquals(
+          Long.valueOf(1L),
+          client
+              .readWriteTransaction()
+              .run(transaction -> transaction.executeUpdate(INSERT_STATEMENT)));
+
+      // Verify that all the RPCs were retried.
+      assertEquals(2, mockSpanner.countRequestsOfType(BatchCreateSessionsRequest.class));
+      assertEquals(4, mockSpanner.countRequestsOfType(ExecuteSqlRequest.class));
+    }
+  }
+}