Rollover avoid heavy lifting in dry-run/validation (#57894)

Fixed two newly introduced issues with rollover:
1. Using auto-expand replicas, rollover could result in unexpected log
messages on future indexes.
2. It did a reroute and other heavy work on the network thread.

Closes #57706
Supersedes #57865
Relates #53965

server/src/internalClusterTest/java/org/elasticsearch/action/admin/indices/rollover/RolloverIT.java

@@ -19,11 +19,18 @@
 
 package org.elasticsearch.action.admin.indices.rollover;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.elasticsearch.ResourceAlreadyExistsException;
 import org.elasticsearch.action.admin.indices.alias.Alias;
 import org.elasticsearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.elasticsearch.action.admin.indices.template.put.PutIndexTemplateRequestBuilder;
 import org.elasticsearch.cluster.ClusterState;
+import org.elasticsearch.cluster.metadata.AutoExpandReplicas;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.cluster.routing.allocation.AllocationService;
+import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.common.unit.ByteSizeUnit;
@@ -32,6 +39,7 @@ import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.InternalSettingsPlugin;
+import org.elasticsearch.test.MockLogAppender;
 
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
@@ -180,10 +188,34 @@ public class RolloverIT extends ESIntegTestCase {
     }
 
     public void testRolloverDryRun() throws Exception {
+        if (randomBoolean()) {
+            PutIndexTemplateRequestBuilder putTemplate = client().admin().indices()
+                .preparePutTemplate("test_index")
+                .setPatterns(List.of("test_index-*"))
+                .setOrder(-1)
+                .setSettings(Settings.builder().put(AutoExpandReplicas.SETTING.getKey(), "0-all"));
+            assertAcked(putTemplate.get());
+        }
         assertAcked(prepareCreate("test_index-1").addAlias(new Alias("test_alias")).get());
         indexDoc("test_index-1", "1", "field", "value");
         flush("test_index-1");
+        ensureGreen();
+        Logger allocationServiceLogger = LogManager.getLogger(AllocationService.class);
+
+        MockLogAppender appender = new MockLogAppender();
+        appender.start();
+        appender.addExpectation(
+            new MockLogAppender.UnseenEventExpectation("no related message logged on dry run",
+                AllocationService.class.getName(), Level.INFO, "*test_index*")
+        );
+        Loggers.addAppender(allocationServiceLogger, appender);
+
         final RolloverResponse response = client().admin().indices().prepareRolloverIndex("test_alias").dryRun(true).get();
+
+        appender.assertAllExpectationsMatched();
+        appender.stop();
+        Loggers.removeAppender(allocationServiceLogger, appender);
+
         assertThat(response.getOldIndex(), equalTo("test_index-1"));
         assertThat(response.getNewIndex(), equalTo("test_index-000002"));
         assertThat(response.isDryRun(), equalTo(true));

server/src/main/java/org/elasticsearch/action/admin/indices/rollover/MetadataRolloverService.java

@@ -88,16 +88,16 @@ public class MetadataRolloverService {
 
     public RolloverResult rolloverClusterState(ClusterState currentState, String rolloverTarget, String newIndexName,
                                                CreateIndexRequest createIndexRequest, List<Condition<?>> metConditions,
-                                               boolean silent) throws Exception {
+                                               boolean silent, boolean onlyValidate) throws Exception {
         validate(currentState.metadata(), rolloverTarget, newIndexName, createIndexRequest);
         final IndexAbstraction indexAbstraction = currentState.metadata().getIndicesLookup().get(rolloverTarget);
         switch (indexAbstraction.getType()) {
             case ALIAS:
                 return rolloverAlias(currentState, (IndexAbstraction.Alias) indexAbstraction, rolloverTarget, newIndexName,
-                    createIndexRequest, metConditions, silent);
+                    createIndexRequest, metConditions, silent, onlyValidate);
             case DATA_STREAM:
                 return  rolloverDataStream(currentState, (IndexAbstraction.DataStream) indexAbstraction, rolloverTarget,
-                    createIndexRequest, metConditions, silent);
+                    createIndexRequest, metConditions, silent, onlyValidate);
             default:
                 // the validate method above prevents this case
                 throw new IllegalStateException("unable to roll over type [" + indexAbstraction.getType().getDisplayName() + "]");
@@ -106,7 +106,7 @@ public class MetadataRolloverService {
 
     private RolloverResult rolloverAlias(ClusterState currentState, IndexAbstraction.Alias alias, String aliasName,
                                          String newIndexName, CreateIndexRequest createIndexRequest, List<Condition<?>> metConditions,
-                                         boolean silent) throws Exception {
+                                         boolean silent, boolean onlyValidate) throws Exception {
         final Metadata metadata = currentState.metadata();
         final IndexMetadata writeIndex = alias.getWriteIndex();
         final AliasMetadata aliasMetadata = writeIndex.getAliases().get(alias.getName());
@@ -122,6 +122,9 @@ public class MetadataRolloverService {
             IndexMetadata.INDEX_HIDDEN_SETTING.get(createIndexRequest.settings()) : null;
         createIndexService.validateIndexName(rolloverIndexName, currentState); // fails if the index already exists
         checkNoDuplicatedAliasInIndexTemplate(metadata, rolloverIndexName, aliasName, isHidden);
+        if (onlyValidate) {
+            return new RolloverResult(rolloverIndexName, sourceIndexName, currentState);
+        }
 
         CreateIndexClusterStateUpdateRequest createIndexClusterStateRequest =
             prepareCreateIndexRequest(unresolvedName, rolloverIndexName, createIndexRequest);
@@ -140,12 +143,16 @@ public class MetadataRolloverService {
 
     private RolloverResult rolloverDataStream(ClusterState currentState, IndexAbstraction.DataStream dataStream, String dataStreamName,
                                               CreateIndexRequest createIndexRequest, List<Condition<?>> metConditions,
-                                              boolean silent) throws Exception {
+                                              boolean silent, boolean onlyValidate) throws Exception {
         lookupTemplateForDataStream(dataStreamName, currentState.metadata());
 
         final DataStream ds = dataStream.getDataStream();
         final IndexMetadata originalWriteIndex = dataStream.getWriteIndex();
         final String newWriteIndexName = DataStream.getDefaultBackingIndexName(ds.getName(), ds.getGeneration() + 1);
+        createIndexService.validateIndexName(newWriteIndexName, currentState); // fails if the index already exists
+        if (onlyValidate) {
+            return new RolloverResult(newWriteIndexName, originalWriteIndex.getIndex().getName(), currentState);
+        }
 
         CreateIndexClusterStateUpdateRequest createIndexClusterStateRequest =
             prepareDataStreamCreateIndexRequest(dataStreamName, newWriteIndexName, createIndexRequest);

server/src/main/java/org/elasticsearch/action/admin/indices/rollover/TransportRolloverAction.java

@@ -97,10 +97,11 @@ public class TransportRolloverAction extends TransportMasterNodeAction<RolloverR
     @Override
     protected void masterOperation(Task task, final RolloverRequest rolloverRequest, final ClusterState state,
                                    final ActionListener<RolloverResponse> listener) throws Exception {
+
         MetadataRolloverService.RolloverResult preResult =
             rolloverService.rolloverClusterState(state,
                 rolloverRequest.getRolloverTarget(), rolloverRequest.getNewIndexName(), rolloverRequest.getCreateIndexRequest(),
-                Collections.emptyList(), true);
+                Collections.emptyList(), true, true);
         Metadata metadata = state.metadata();
         String sourceIndexName = preResult.sourceIndexName;
         String rolloverIndexName = preResult.rolloverIndexName;
@@ -130,7 +131,7 @@ public class TransportRolloverAction extends TransportMasterNodeAction<RolloverR
                             public ClusterState execute(ClusterState currentState) throws Exception {
                                 MetadataRolloverService.RolloverResult rolloverResult = rolloverService.rolloverClusterState(currentState,
                                     rolloverRequest.getRolloverTarget(), rolloverRequest.getNewIndexName(),
-                                    rolloverRequest.getCreateIndexRequest(), metConditions, false);
+                                    rolloverRequest.getCreateIndexRequest(), metConditions, false, false);
                                 if (rolloverResult.sourceIndexName.equals(sourceIndexName) == false) {
                                     throw new ElasticsearchException("Concurrent modification of alias [{}] during rollover",
                                         rolloverRequest.getRolloverTarget());

server/src/test/java/org/elasticsearch/action/admin/indices/rollover/MetadataRolloverServiceTests.java

@@ -56,6 +56,7 @@ import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.shard.IndexEventListener;
 import org.elasticsearch.indices.IndicesService;
+import org.elasticsearch.indices.InvalidIndexNameException;
 import org.elasticsearch.indices.ShardLimitValidator;
 import org.elasticsearch.test.ClusterServiceUtils;
 import org.elasticsearch.test.ESTestCase;
@@ -80,7 +81,12 @@ import static org.hamcrest.Matchers.lessThanOrEqualTo;
 import static org.hamcrest.Matchers.nullValue;
 import static org.mockito.AdditionalAnswers.returnsFirstArg;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.same;
+import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
 import static org.mockito.Mockito.when;
 
 public class MetadataRolloverServiceTests extends ESTestCase {
@@ -490,7 +496,7 @@ public class MetadataRolloverServiceTests extends ESTestCase {
             long before = testThreadPool.absoluteTimeInMillis();
             MetadataRolloverService.RolloverResult rolloverResult =
                 rolloverService.rolloverClusterState(clusterState, aliasName, newIndexName, createIndexRequest, metConditions,
-                    randomBoolean());
+                    randomBoolean(), false);
             long after = testThreadPool.absoluteTimeInMillis();
 
             newIndexName = newIndexName == null ? indexPrefix + "2" : newIndexName;
@@ -557,7 +563,7 @@ public class MetadataRolloverServiceTests extends ESTestCase {
             long before = testThreadPool.absoluteTimeInMillis();
             MetadataRolloverService.RolloverResult rolloverResult =
                 rolloverService.rolloverClusterState(clusterState, dataStream.getName(), null, createIndexRequest, metConditions,
-                    randomBoolean());
+                    randomBoolean(), false);
             long after = testThreadPool.absoluteTimeInMillis();
 
             String sourceIndexName = DataStream.getDefaultBackingIndexName(dataStream.getName(), dataStream.getGeneration());
@@ -585,6 +591,69 @@ public class MetadataRolloverServiceTests extends ESTestCase {
         }
     }
 
+    public void testValidation() throws Exception {
+        final String rolloverTarget;
+        final String sourceIndexName;
+        final String defaultRolloverIndexName;
+        final boolean useDataStream = randomBoolean();
+        final Metadata.Builder builder = Metadata.builder();
+        if (useDataStream) {
+            DataStream dataStream = DataStreamTests.randomInstance();
+            rolloverTarget = dataStream.getName();
+            sourceIndexName = dataStream.getIndices().get(dataStream.getIndices().size() - 1).getName();
+            defaultRolloverIndexName = DataStream.getDefaultBackingIndexName(dataStream.getName(), dataStream.getGeneration() + 1);
+            ComposableIndexTemplate template = new ComposableIndexTemplate(List.of(dataStream.getName() + "*"), null, null, null, null,
+                null, new ComposableIndexTemplate.DataStreamTemplate("@timestamp"));
+            builder.put("template", template);
+            for (Index index : dataStream.getIndices()) {
+                builder.put(DataStreamTestHelper.getIndexMetadataBuilderForIndex(index));
+            }
+            builder.put(dataStream);
+        } else {
+            String indexPrefix = "logs-index-00000";
+            rolloverTarget = "logs-alias";
+            sourceIndexName = indexPrefix + "1";
+            defaultRolloverIndexName = indexPrefix + "2";
+            final IndexMetadata.Builder indexMetadata = IndexMetadata.builder(sourceIndexName)
+                .putAlias(AliasMetadata.builder(rolloverTarget).writeIndex(true).build()).settings(settings(Version.CURRENT))
+                .numberOfShards(1).numberOfReplicas(1);
+            builder.put(indexMetadata);
+        }
+        final ClusterState clusterState = ClusterState.builder(new ClusterName("test")).metadata(builder).build();
+
+        MetadataCreateIndexService createIndexService = mock(MetadataCreateIndexService.class);
+        MetadataIndexAliasesService metadataIndexAliasesService = mock(MetadataIndexAliasesService.class);
+        IndexNameExpressionResolver mockIndexNameExpressionResolver = mock(IndexNameExpressionResolver.class);
+        when(mockIndexNameExpressionResolver.resolveDateMathExpression(any())).then(returnsFirstArg());
+        MetadataRolloverService rolloverService = new MetadataRolloverService(null, createIndexService, metadataIndexAliasesService,
+            mockIndexNameExpressionResolver);
+
+        String newIndexName = useDataStream == false && randomBoolean() ? "logs-index-9" : null;
+
+        MetadataRolloverService.RolloverResult rolloverResult = rolloverService.rolloverClusterState(clusterState, rolloverTarget,
+            newIndexName, new CreateIndexRequest("_na_"), null, randomBoolean(), true);
+
+        newIndexName = newIndexName == null ? defaultRolloverIndexName : newIndexName;
+        assertEquals(sourceIndexName, rolloverResult.sourceIndexName);
+        assertEquals(newIndexName, rolloverResult.rolloverIndexName);
+        assertSame(rolloverResult.clusterState, clusterState);
+
+        verify(createIndexService).validateIndexName(any(), same(clusterState));
+        verifyZeroInteractions(createIndexService);
+        verifyZeroInteractions(metadataIndexAliasesService);
+
+        reset(createIndexService);
+        doThrow(new InvalidIndexNameException("test", "invalid")).when(createIndexService).validateIndexName(any(), any());
+
+        expectThrows(InvalidIndexNameException.class,
+            () -> rolloverService.rolloverClusterState(clusterState, rolloverTarget, null, new CreateIndexRequest("_na_"), null,
+                randomBoolean(), randomBoolean()));
+
+        verify(createIndexService).validateIndexName(any(), same(clusterState));
+        verifyZeroInteractions(createIndexService);
+        verifyZeroInteractions(metadataIndexAliasesService);
+    }
+
     public void testRolloverClusterStateForDataStreamNoTemplate() throws Exception {
         final DataStream dataStream = DataStreamTests.randomInstance();
         Metadata.Builder builder = Metadata.builder();
@@ -614,7 +683,7 @@ public class MetadataRolloverServiceTests extends ESTestCase {
         CreateIndexRequest createIndexRequest = new CreateIndexRequest("_na_");
 
         Exception e = expectThrows(IllegalArgumentException.class, () -> rolloverService.rolloverClusterState(clusterState,
-            dataStream.getName(), null, createIndexRequest, metConditions, false));
+            dataStream.getName(), null, createIndexRequest, metConditions, false, randomBoolean()));
         assertThat(e.getMessage(), equalTo("no matching index template found for data stream [" + dataStream.getName() + "]"));
     }