Move SlowLogFieldProvider instantiation to node construction

docs/changelog/117949.yaml

@@ -0,0 +1,5 @@
+pr: 117949
+summary: Move `SlowLogFieldProvider` instantiation to node construction
+area: Infra/Logging
+type: bug
+issues: []

server/src/main/java/org/elasticsearch/indices/IndicesService.java

@@ -261,6 +261,7 @@ public class IndicesService extends AbstractLifecycleComponent
     private final MapperMetrics mapperMetrics;
     private final PostRecoveryMerger postRecoveryMerger;
     private final List<SearchOperationListener> searchOperationListeners;
+    final SlowLogFieldProvider slowLogFieldProvider; // pkg-private for testing
 
     @Override
     protected void doStart() {
@@ -379,6 +380,7 @@ public void onRemoval(ShardId shardId, String fieldName, boolean wasEvicted, lon
         this.timestampFieldMapperService = new TimestampFieldMapperService(settings, threadPool, this);
         this.postRecoveryMerger = new PostRecoveryMerger(settings, threadPool.executor(ThreadPool.Names.FORCE_MERGE), this::getShardOrNull);
         this.searchOperationListeners = builder.searchOperationListener;
+        this.slowLogFieldProvider = builder.slowLogFieldProvider;
     }
 
     private static final String DANGLING_INDICES_UPDATE_THREAD_NAME = "DanglingIndices#updateTask";
@@ -749,7 +751,7 @@ private synchronized IndexService createIndexService(
             () -> allowExpensiveQueries,
             indexNameExpressionResolver,
             recoveryStateFactories,
-            loadSlowLogFieldProvider(),
+            slowLogFieldProvider,
             mapperMetrics,
             searchOperationListeners
         );
@@ -828,7 +830,7 @@ public synchronized MapperService createIndexMapperServiceForValidation(IndexMet
             () -> allowExpensiveQueries,
             indexNameExpressionResolver,
             recoveryStateFactories,
-            loadSlowLogFieldProvider(),
+            slowLogFieldProvider,
             mapperMetrics,
             searchOperationListeners
         );
@@ -1434,31 +1436,6 @@ int numPendingDeletes(Index index) {
         }
     }
 
-    // pkg-private for testing
-    SlowLogFieldProvider loadSlowLogFieldProvider() {
-        List<? extends SlowLogFieldProvider> slowLogFieldProviders = pluginsService.loadServiceProviders(SlowLogFieldProvider.class);
-        return new SlowLogFieldProvider() {
-            @Override
-            public void init(IndexSettings indexSettings) {
-                slowLogFieldProviders.forEach(provider -> provider.init(indexSettings));
-            }
-
-            @Override
-            public Map<String, String> indexSlowLogFields() {
-                return slowLogFieldProviders.stream()
-                    .flatMap(provider -> provider.indexSlowLogFields().entrySet().stream())
-                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
-            }
-
-            @Override
-            public Map<String, String> searchSlowLogFields() {
-                return slowLogFieldProviders.stream()
-                    .flatMap(provider -> provider.searchSlowLogFields().entrySet().stream())
-                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
-            }
-        };
-    }
-
     /**
      * Checks if all pending deletes have completed. Used by tests to ensure we don't check directory contents
      * while deletion still ongoing. * The reason is that, on Windows, browsing the directory contents can interfere

server/src/main/java/org/elasticsearch/indices/IndicesServiceBuilder.java

@@ -23,6 +23,7 @@
 import org.elasticsearch.features.FeatureService;
 import org.elasticsearch.gateway.MetaStateService;
 import org.elasticsearch.index.IndexSettings;
+import org.elasticsearch.index.SlowLogFieldProvider;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.engine.EngineFactory;
 import org.elasticsearch.index.mapper.MapperMetrics;
@@ -76,6 +77,20 @@ public class IndicesServiceBuilder {
     CheckedBiConsumer<ShardSearchRequest, StreamOutput, IOException> requestCacheKeyDifferentiator;
     MapperMetrics mapperMetrics;
     List<SearchOperationListener> searchOperationListener = List.of();
+    SlowLogFieldProvider slowLogFieldProvider = new SlowLogFieldProvider() {
+        @Override
+        public void init(IndexSettings indexSettings) {}
+
+        @Override
+        public Map<String, String> indexSlowLogFields() {
+            return Map.of();
+        }
+
+        @Override
+        public Map<String, String> searchSlowLogFields() {
+            return Map.of();
+        }
+    };
 
     public IndicesServiceBuilder settings(Settings settings) {
         this.settings = settings;
@@ -188,6 +203,11 @@ public IndicesServiceBuilder searchOperationListeners(List<SearchOperationListen
         return this;
     }
 
+    public IndicesServiceBuilder slowLogFieldProvider(SlowLogFieldProvider slowLogFieldProvider) {
+        this.slowLogFieldProvider = slowLogFieldProvider;
+        return this;
+    }
+
     public IndicesService build() {
         Objects.requireNonNull(settings);
         Objects.requireNonNull(pluginsService);
@@ -213,6 +233,7 @@ public IndicesService build() {
         Objects.requireNonNull(snapshotCommitSuppliers);
         Objects.requireNonNull(mapperMetrics);
         Objects.requireNonNull(searchOperationListener);
+        Objects.requireNonNull(slowLogFieldProvider);
 
         // collect engine factory providers from plugins
         engineFactoryProviders = pluginsService.filterPlugins(EnginePlugin.class)

server/src/main/java/org/elasticsearch/node/NodeConstruction.java

@@ -110,7 +110,9 @@
 import org.elasticsearch.index.IndexMode;
 import org.elasticsearch.index.IndexSettingProvider;
 import org.elasticsearch.index.IndexSettingProviders;
+import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexingPressure;
+import org.elasticsearch.index.SlowLogFieldProvider;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.mapper.MapperMetrics;
 import org.elasticsearch.index.mapper.SourceFieldMetrics;
@@ -800,6 +802,30 @@ private void construct(
             new ShardSearchPhaseAPMMetrics(telemetryProvider.getMeterRegistry())
         );
 
+        List<? extends SlowLogFieldProvider> slowLogFieldProviders = pluginsService.loadServiceProviders(SlowLogFieldProvider.class);
+        // NOTE: the response of index/search slow log fields below must be calculated dynamically on every call
+        // because the responses may change dynamically at runtime
+        SlowLogFieldProvider slowLogFieldProvider = new SlowLogFieldProvider() {
+            @Override
+            public void init(IndexSettings indexSettings) {
+                slowLogFieldProviders.forEach(provider -> provider.init(indexSettings));
+            }
+
+            @Override
+            public Map<String, String> indexSlowLogFields() {
+                return slowLogFieldProviders.stream()
+                    .flatMap(provider -> provider.indexSlowLogFields().entrySet().stream())
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+            }
+
+            @Override
+            public Map<String, String> searchSlowLogFields() {
+                return slowLogFieldProviders.stream()
+                    .flatMap(provider -> provider.searchSlowLogFields().entrySet().stream())
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+            }
+        };
+
         IndicesService indicesService = new IndicesServiceBuilder().settings(settings)
             .pluginsService(pluginsService)
             .nodeEnvironment(nodeEnvironment)
@@ -821,6 +847,7 @@ private void construct(
             .requestCacheKeyDifferentiator(searchModule.getRequestCacheKeyDifferentiator())
             .mapperMetrics(mapperMetrics)
             .searchOperationListeners(searchOperationListeners)
+            .slowLogFieldProvider(slowLogFieldProvider)
             .build();
 
         final var parameters = new IndexSettingProvider.Parameters(clusterService, indicesService::createIndexMapperServiceForValidation);

server/src/test/java/org/elasticsearch/indices/IndicesServiceTests.java

@@ -803,7 +803,7 @@ public void testLoadSlowLogFieldProvider() {
         TestAnotherSlowLogFieldProvider.setFields(Map.of("key2", "value2"));
 
         var indicesService = getIndicesService();
-        SlowLogFieldProvider fieldProvider = indicesService.loadSlowLogFieldProvider();
+        SlowLogFieldProvider fieldProvider = indicesService.slowLogFieldProvider;
 
         // The map of fields from the two providers are merged to a single map of fields
         assertEquals(Map.of("key1", "value1", "key2", "value2"), fieldProvider.searchSlowLogFields());