Improve logging of put-mapping failures (#121372)

No sense in converting to a list just to convert to a string, we may as
well convert directly to a string. Also removes the unnecessary extra
`[]` wrapper.

Author: DaveCTurner

server/src/internalClusterTest/java/org/elasticsearch/action/admin/indices/mapping/put/PutMappingIT.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.action.admin.indices.mapping.put;
+
+import org.apache.logging.log4j.Level;
+import org.elasticsearch.action.support.master.AcknowledgedResponse;
+import org.elasticsearch.test.ESSingleNodeTestCase;
+import org.elasticsearch.test.MockLog;
+import org.elasticsearch.test.junit.annotations.TestLogging;
+
+import static org.hamcrest.Matchers.equalTo;
+
+public class PutMappingIT extends ESSingleNodeTestCase {
+
+    @TestLogging(
+        reason = "testing DEBUG logging",
+        value = "org.elasticsearch.action.admin.indices.mapping.put.TransportPutMappingAction:DEBUG"
+    )
+    public void testFailureLogging() {
+        final var indexName = randomIdentifier();
+        createIndex(indexName);
+        final var fieldName = randomIdentifier();
+        safeGet(client().execute(TransportPutMappingAction.TYPE, new PutMappingRequest(indexName).source(fieldName, "type=keyword")));
+        MockLog.assertThatLogger(
+            () -> assertThat(
+                asInstanceOf(
+                    IllegalArgumentException.class,
+                    safeAwaitFailure(
+                        AcknowledgedResponse.class,
+                        l -> client().execute(
+                            TransportPutMappingAction.TYPE,
+                            new PutMappingRequest(indexName).source(fieldName, "type=long"),
+                            l
+                        )
+                    )
+                ).getMessage(),
+                equalTo("mapper [" + fieldName + "] cannot be changed from type [keyword] to [long]")
+            ),
+            TransportPutMappingAction.class,
+            new MockLog.SeenEventExpectation(
+                "failure message",
+                TransportPutMappingAction.class.getCanonicalName(),
+                Level.DEBUG,
+                "failed to put mappings on indices [[" + indexName
+            )
+        );
+    }
+}

server/src/main/java/org/elasticsearch/action/admin/indices/mapping/put/TransportPutMappingAction.java

@@ -36,7 +36,6 @@
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -126,7 +125,7 @@ protected void masterOperation(
 
             performMappingUpdate(concreteIndices, request, listener, metadataMappingService, false);
         } catch (IndexNotFoundException ex) {
-            logger.debug(() -> "failed to put mappings on indices [" + Arrays.asList(request.indices() + "]"), ex);
+            logger.debug(() -> "failed to put mappings on indices " + Arrays.toString(request.indices()), ex);
             throw ex;
         }
     }
@@ -162,25 +161,21 @@ static void performMappingUpdate(
         MetadataMappingService metadataMappingService,
         boolean autoUpdate
     ) {
-        final ActionListener<AcknowledgedResponse> wrappedListener = listener.delegateResponse((l, e) -> {
-            logger.debug(() -> "failed to put mappings on indices [" + Arrays.asList(concreteIndices) + "]", e);
+        ActionListener.run(listener.delegateResponse((l, e) -> {
+            logger.debug(() -> "failed to put mappings on indices " + Arrays.toString(concreteIndices), e);
             l.onFailure(e);
-        });
-        final PutMappingClusterStateUpdateRequest updateRequest;
-        try {
-            updateRequest = new PutMappingClusterStateUpdateRequest(
-                request.masterNodeTimeout(),
-                request.ackTimeout(),
-                request.source(),
-                autoUpdate,
-                concreteIndices
-            );
-        } catch (IOException e) {
-            wrappedListener.onFailure(e);
-            return;
-        }
-
-        metadataMappingService.putMapping(updateRequest, wrappedListener);
+        }),
+            wrappedListener -> metadataMappingService.putMapping(
+                new PutMappingClusterStateUpdateRequest(
+                    request.masterNodeTimeout(),
+                    request.ackTimeout(),
+                    request.source(),
+                    autoUpdate,
+                    concreteIndices
+                ),
+                wrappedListener
+            )
+        );
     }
 
     static String checkForFailureStoreViolations(ClusterState clusterState, Index[] concreteIndices, PutMappingRequest request) {

server/src/main/java/org/elasticsearch/cluster/metadata/MetadataMappingService.java

@@ -56,7 +56,7 @@ public class MetadataMappingService {
     public MetadataMappingService(ClusterService clusterService, IndicesService indicesService) {
         this.clusterService = clusterService;
         this.indicesService = indicesService;
-        taskQueue = clusterService.createTaskQueue("put-mapping", Priority.HIGH, new PutMappingExecutor());
+        this.taskQueue = clusterService.createTaskQueue("put-mapping", Priority.HIGH, new PutMappingExecutor());
     }
 
     record PutMappingClusterStateUpdateTask(PutMappingClusterStateUpdateRequest request, ActionListener<AcknowledgedResponse> listener)