Add additional debug logging for indexing failure.

This change adds a new IndexingOperationListener that logs debug logging for indexing failures.

Today `IndexShard` logger needs to be set to TRACE in order to see indexing failures. This logger is very verbose and logs many other aspects of indexing at trace level. This new logger is targeted just for seeing indexing failures.

Relates elastic#117700

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -345,8 +345,9 @@ public IndexShard(
         this.mapperService = mapperService;
         this.indexCache = indexCache;
         this.internalIndexingStats = new InternalIndexingStats();
+        var indexingFailuresDebugListener = new IndexingFailuresDebugListener(this);
         this.indexingOperationListeners = new IndexingOperationListener.CompositeListener(
-            CollectionUtils.appendToCopyNoNullElements(listeners, internalIndexingStats),
+            CollectionUtils.appendToCopyNoNullElements(listeners, internalIndexingStats, indexingFailuresDebugListener),
             logger
         );
         this.bulkOperationListener = new ShardBulkStats();

server/src/main/java/org/elasticsearch/index/shard/IndexingFailuresDebugListener.java

@@ -0,0 +1,54 @@
+/*
+ * 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.index.shard;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.elasticsearch.index.engine.Engine;
+
+import static org.elasticsearch.core.Strings.format;
+
+public class IndexingFailuresDebugListener implements IndexingOperationListener {
+
+    private static final Logger LOGGER = LogManager.getLogger(IndexingFailuresDebugListener.class);
+
+    private final IndexShard indexShard;
+
+    public IndexingFailuresDebugListener(IndexShard indexShard) {
+        this.indexShard = indexShard;
+    }
+
+    @Override
+    public void postIndex(ShardId shardId, Engine.Index index, Engine.IndexResult result) {
+        if (LOGGER.isDebugEnabled()) {
+            if (result.getResultType() == Engine.Result.Type.FAILURE) {
+                postIndex(shardId, index, result.getFailure());
+            }
+        }
+    }
+
+    @Override
+    public void postIndex(ShardId shardId, Engine.Index index, Exception ex) {
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug(
+                () -> format(
+                    "index-fail [%s] seq# [%s] allocation-id [%s] primaryTerm [%s] operationPrimaryTerm [%s] origin [%s]",
+                    index.id(),
+                    index.seqNo(),
+                    indexShard.routingEntry().allocationId(),
+                    index.primaryTerm(),
+                    indexShard.getOperationPrimaryTerm(),
+                    index.origin()
+                ),
+                ex
+            );
+        }
+    }
+}

server/src/test/java/org/elasticsearch/index/shard/IndexingFailuresDebugListenerTests.java

@@ -0,0 +1,139 @@
+/*
+ * 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.index.shard;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.elasticsearch.cluster.routing.ShardRoutingState;
+import org.elasticsearch.cluster.routing.TestShardRouting;
+import org.elasticsearch.common.logging.Loggers;
+import org.elasticsearch.common.logging.MockAppender;
+import org.elasticsearch.index.engine.Engine;
+import org.elasticsearch.index.engine.EngineTestCase;
+import org.elasticsearch.index.mapper.ParsedDocument;
+import org.elasticsearch.index.mapper.Uid;
+import org.elasticsearch.test.ESTestCase;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.nullValue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class IndexingFailuresDebugListenerTests extends ESTestCase {
+
+    static MockAppender appender;
+    static Logger testLogger1 = LogManager.getLogger(IndexingFailuresDebugListener.class);
+    static Level origLogLevel = testLogger1.getLevel();
+
+    @BeforeClass
+    public static void init() throws IllegalAccessException {
+        appender = new MockAppender("mock_appender");
+        appender.start();
+        Loggers.addAppender(testLogger1, appender);
+        Loggers.setLevel(testLogger1, randomBoolean() ? Level.DEBUG : Level.TRACE);
+    }
+
+    @AfterClass
+    public static void cleanup() {
+        Loggers.removeAppender(testLogger1, appender);
+        appender.stop();
+
+        Loggers.setLevel(testLogger1, origLogLevel);
+    }
+
+    public void testPostIndexException() {
+        var shardId = ShardId.fromString("[index][123]");
+        var mockShard = mock(IndexShard.class);
+        var shardRouting = TestShardRouting.newShardRouting(shardId, "node-id", true, ShardRoutingState.STARTED);
+        when(mockShard.routingEntry()).thenReturn(shardRouting);
+        when(mockShard.getOperationPrimaryTerm()).thenReturn(1L);
+        IndexingFailuresDebugListener indexingFailuresDebugListener = new IndexingFailuresDebugListener(mockShard);
+
+        ParsedDocument doc = EngineTestCase.createParsedDoc("1", null);
+        Engine.Index index = new Engine.Index(Uid.encodeId("doc_id"), 1, doc);
+        indexingFailuresDebugListener.postIndex(shardId, index, new RuntimeException("test exception"));
+        String message = appender.getLastEventAndReset().getMessage().getFormattedMessage();
+        assertThat(
+            message,
+            equalTo(
+                "index-fail [1] seq# [-2] allocation-id ["
+                    + shardRouting.allocationId()
+                    + "] primaryTerm [1] operationPrimaryTerm [1] origin [PRIMARY]"
+            )
+        );
+    }
+
+    public void testPostIndexExceptionInfoLevel() {
+        var previousLevel = testLogger1.getLevel();
+        try {
+            Loggers.setLevel(testLogger1, randomBoolean() ? Level.INFO : Level.WARN);
+            var shardId = ShardId.fromString("[index][123]");
+            var mockShard = mock(IndexShard.class);
+            var shardRouting = TestShardRouting.newShardRouting(shardId, "node-id", true, ShardRoutingState.STARTED);
+            when(mockShard.routingEntry()).thenReturn(shardRouting);
+            when(mockShard.getOperationPrimaryTerm()).thenReturn(1L);
+            IndexingFailuresDebugListener indexingFailuresDebugListener = new IndexingFailuresDebugListener(mockShard);
+
+            ParsedDocument doc = EngineTestCase.createParsedDoc("1", null);
+            Engine.Index index = new Engine.Index(Uid.encodeId("doc_id"), 1, doc);
+            indexingFailuresDebugListener.postIndex(shardId, index, new RuntimeException("test exception"));
+            assertThat(appender.getLastEventAndReset(), nullValue());
+        } finally {
+            Loggers.setLevel(testLogger1, previousLevel);
+        }
+    }
+
+    public void testPostIndexFailure() {
+        var shardId = ShardId.fromString("[index][123]");
+        var mockShard = mock(IndexShard.class);
+        var shardRouting = TestShardRouting.newShardRouting(shardId, "node-id", true, ShardRoutingState.STARTED);
+        when(mockShard.routingEntry()).thenReturn(shardRouting);
+        when(mockShard.getOperationPrimaryTerm()).thenReturn(1L);
+        IndexingFailuresDebugListener indexingFailuresDebugListener = new IndexingFailuresDebugListener(mockShard);
+
+        ParsedDocument doc = EngineTestCase.createParsedDoc("1", null);
+        Engine.Index index = new Engine.Index(Uid.encodeId("doc_id"), 1, doc);
+        Engine.IndexResult indexResult = mock(Engine.IndexResult.class);
+        when(indexResult.getResultType()).thenReturn(Engine.Result.Type.FAILURE);
+        when(indexResult.getFailure()).thenReturn(new RuntimeException("test exception"));
+        indexingFailuresDebugListener.postIndex(shardId, index, indexResult);
+        String message = appender.getLastEventAndReset().getMessage().getFormattedMessage();
+        assertThat(
+            message,
+            equalTo(
+                "index-fail [1] seq# [-2] allocation-id ["
+                    + shardRouting.allocationId()
+                    + "] primaryTerm [1] operationPrimaryTerm [1] origin [PRIMARY]"
+            )
+        );
+    }
+
+    public void testPostIndex() {
+        var shardId = ShardId.fromString("[index][123]");
+        var mockShard = mock(IndexShard.class);
+        var shardRouting = TestShardRouting.newShardRouting(shardId, "node-id", true, ShardRoutingState.STARTED);
+        when(mockShard.routingEntry()).thenReturn(shardRouting);
+        when(mockShard.getOperationPrimaryTerm()).thenReturn(1L);
+        IndexingFailuresDebugListener indexingFailuresDebugListener = new IndexingFailuresDebugListener(mockShard);
+
+        ParsedDocument doc = EngineTestCase.createParsedDoc("1", null);
+        Engine.Index index = new Engine.Index(Uid.encodeId("doc_id"), 1, doc);
+        Engine.IndexResult indexResult = mock(Engine.IndexResult.class);
+        when(indexResult.getResultType()).thenReturn(Engine.Result.Type.SUCCESS);
+        when(indexResult.getFailure()).thenReturn(new RuntimeException("test exception"));
+        indexingFailuresDebugListener.postIndex(shardId, index, indexResult);
+        assertThat(appender.getLastEventAndReset(), nullValue());
+    }
+
+
+}