Add the ability to reload search analyzers during shard recovery (#97421)

This change adds the ability for reloadable search analysers to adapt their loading based on
the index creation context. It is useful for reloadable search analysers that need to load
expensive resources from indices or disk. In such case they can defer the loading of the
resource during the shard recovery and avoid blocking a master or a create index thread.
---------

Co-authored-by: Mayya Sharipova <mayya.sharipova@elastic.co>

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/CommonAnalysisPlugin.java

@@ -154,7 +154,6 @@ public class CommonAnalysisPlugin extends Plugin implements AnalysisPlugin, Scri
 
     private final SetOnce<ScriptService> scriptServiceHolder = new SetOnce<>();
     private final SetOnce<SynonymsManagementAPIService> synonymsManagementServiceHolder = new SetOnce<>();
-    private final SetOnce<ThreadPool> threadPoolHolder = new SetOnce<>();
 
     @Override
     public Collection<Object> createComponents(
@@ -175,7 +174,6 @@ public class CommonAnalysisPlugin extends Plugin implements AnalysisPlugin, Scri
     ) {
         this.scriptServiceHolder.set(scriptService);
         this.synonymsManagementServiceHolder.set(new SynonymsManagementAPIService(client));
-        this.threadPoolHolder.set(threadPool);
         return Collections.emptyList();
     }
 
@@ -341,22 +339,11 @@ public class CommonAnalysisPlugin extends Plugin implements AnalysisPlugin, Scri
         filters.put("stemmer", StemmerTokenFilterFactory::new);
         filters.put(
             "synonym",
-            requiresAnalysisSettings(
+            requiresAnalysisSettings((i, e, n, s) -> new SynonymTokenFilterFactory(i, e, n, s, synonymsManagementServiceHolder.get()))
-                (i, e, n, s) -> new SynonymTokenFilterFactory(i, e, n, s, synonymsManagementServiceHolder.get(), threadPoolHolder.get())
-            )
         );
         filters.put(
             "synonym_graph",
-            requiresAnalysisSettings(
+            requiresAnalysisSettings((i, e, n, s) -> new SynonymGraphTokenFilterFactory(i, e, n, s, synonymsManagementServiceHolder.get()))
-                (i, e, n, s) -> new SynonymGraphTokenFilterFactory(
-                    i,
-                    e,
-                    n,
-                    s,
-                    synonymsManagementServiceHolder.get(),
-                    threadPoolHolder.get()
-                )
-            )
         );
         filters.put("trim", TrimTokenFilterFactory::new);
         filters.put("truncate", requiresAnalysisSettings(TruncateTokenFilterFactory::new));

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/MultiplexerTokenFilterFactory.java

@@ -16,6 +16,7 @@ import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AbstractTokenFilterFactory;
 import org.elasticsearch.index.analysis.AnalysisMode;
@@ -51,6 +52,7 @@ public class MultiplexerTokenFilterFactory extends AbstractTokenFilterFactory {
 
     @Override
     public TokenFilterFactory getChainAwareTokenFilterFactory(
+        IndexCreationContext context,
         TokenizerFactory tokenizer,
         List<CharFilterFactory> charFilters,
         List<TokenFilterFactory> previousTokenFilters,
@@ -66,7 +68,7 @@ public class MultiplexerTokenFilterFactory extends AbstractTokenFilterFactory {
             String[] parts = Strings.tokenizeToStringArray(filter, ",");
             if (parts.length == 1) {
                 TokenFilterFactory factory = resolveFilterFactory(allFilters, parts[0]);
-                factory = factory.getChainAwareTokenFilterFactory(tokenizer, charFilters, previousTokenFilters, allFilters);
+                factory = factory.getChainAwareTokenFilterFactory(context, tokenizer, charFilters, previousTokenFilters, allFilters);
                 filters.add(factory);
                 mode = mode.merge(factory.getAnalysisMode());
             } else {
@@ -74,7 +76,7 @@ public class MultiplexerTokenFilterFactory extends AbstractTokenFilterFactory {
                 List<TokenFilterFactory> chain = new ArrayList<>();
                 for (String subfilter : parts) {
                     TokenFilterFactory factory = resolveFilterFactory(allFilters, subfilter);
-                    factory = factory.getChainAwareTokenFilterFactory(tokenizer, charFilters, existingChain, allFilters);
+                    factory = factory.getChainAwareTokenFilterFactory(context, tokenizer, charFilters, existingChain, allFilters);
                     chain.add(factory);
                     existingChain.add(factory);
                     mode = mode.merge(factory.getAnalysisMode());

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/ScriptedConditionTokenFilterFactory.java

@@ -11,6 +11,7 @@ package org.elasticsearch.analysis.common;
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.miscellaneous.ConditionalTokenFilter;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AbstractTokenFilterFactory;
 import org.elasticsearch.index.analysis.CharFilterFactory;
@@ -57,6 +58,7 @@ public class ScriptedConditionTokenFilterFactory extends AbstractTokenFilterFact
 
     @Override
     public TokenFilterFactory getChainAwareTokenFilterFactory(
+        IndexCreationContext context,
         TokenizerFactory tokenizer,
         List<CharFilterFactory> charFilters,
         List<TokenFilterFactory> previousTokenFilters,
@@ -71,7 +73,7 @@ public class ScriptedConditionTokenFilterFactory extends AbstractTokenFilterFact
                     "ScriptedConditionTokenFilter [" + name() + "] refers to undefined token filter [" + filter + "]"
                 );
             }
-            tff = tff.getChainAwareTokenFilterFactory(tokenizer, charFilters, existingChain, allFilters);
+            tff = tff.getChainAwareTokenFilterFactory(context, tokenizer, charFilters, existingChain, allFilters);
             filters.add(tff);
             existingChain.add(tff);
         }

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/SynonymGraphTokenFilterFactory.java

@@ -14,13 +14,13 @@ import org.apache.lucene.analysis.synonym.SynonymGraphFilter;
 import org.apache.lucene.analysis.synonym.SynonymMap;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisMode;
 import org.elasticsearch.index.analysis.CharFilterFactory;
 import org.elasticsearch.index.analysis.TokenFilterFactory;
 import org.elasticsearch.index.analysis.TokenizerFactory;
 import org.elasticsearch.synonyms.SynonymsManagementAPIService;
-import org.elasticsearch.threadpool.ThreadPool;
 
 import java.util.List;
 import java.util.function.Function;
@@ -32,10 +32,9 @@ public class SynonymGraphTokenFilterFactory extends SynonymTokenFilterFactory {
         Environment env,
         String name,
         Settings settings,
-        SynonymsManagementAPIService synonymsManagementAPIService,
+        SynonymsManagementAPIService synonymsManagementAPIService
-        ThreadPool threadPool
     ) {
-        super(indexSettings, env, name, settings, synonymsManagementAPIService, threadPool);
+        super(indexSettings, env, name, settings, synonymsManagementAPIService);
     }
 
     @Override
@@ -45,13 +44,14 @@ public class SynonymGraphTokenFilterFactory extends SynonymTokenFilterFactory {
 
     @Override
     public TokenFilterFactory getChainAwareTokenFilterFactory(
+        IndexCreationContext context,
         TokenizerFactory tokenizer,
         List<CharFilterFactory> charFilters,
         List<TokenFilterFactory> previousTokenFilters,
         Function<String, TokenFilterFactory> allFilters
     ) {
         final Analyzer analyzer = buildSynonymAnalyzer(tokenizer, charFilters, previousTokenFilters);
-        ReaderWithOrigin rulesFromSettings = getRulesFromSettings(environment);
+        ReaderWithOrigin rulesFromSettings = getRulesFromSettings(environment, context);
         final SynonymMap synonyms = buildSynonyms(analyzer, rulesFromSettings);
         final String name = name();
         return new TokenFilterFactory() {

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/SynonymTokenFilterFactory.java

@@ -12,11 +12,11 @@ import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.synonym.SynonymFilter;
 import org.apache.lucene.analysis.synonym.SynonymMap;
-import org.elasticsearch.cluster.service.MasterService;
 import org.elasticsearch.common.logging.DeprecationCategory;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AbstractTokenFilterFactory;
 import org.elasticsearch.index.analysis.Analysis;
@@ -27,7 +27,6 @@ import org.elasticsearch.index.analysis.TokenFilterFactory;
 import org.elasticsearch.index.analysis.TokenizerFactory;
 import org.elasticsearch.synonyms.SynonymsAPI;
 import org.elasticsearch.synonyms.SynonymsManagementAPIService;
-import org.elasticsearch.threadpool.ThreadPool;
 
 import java.io.Reader;
 import java.io.StringReader;
@@ -45,15 +44,13 @@ public class SynonymTokenFilterFactory extends AbstractTokenFilterFactory {
     protected final Environment environment;
     protected final AnalysisMode analysisMode;
     private final SynonymsManagementAPIService synonymsManagementAPIService;
-    private final ThreadPool threadPool;
 
     SynonymTokenFilterFactory(
         IndexSettings indexSettings,
         Environment env,
         String name,
         Settings settings,
-        SynonymsManagementAPIService synonymsManagementAPIService,
+        SynonymsManagementAPIService synonymsManagementAPIService
-        ThreadPool threadPool
     ) {
         super(name, settings);
         this.settings = settings;
@@ -73,7 +70,6 @@ public class SynonymTokenFilterFactory extends AbstractTokenFilterFactory {
         this.analysisMode = updateable ? AnalysisMode.SEARCH_TIME : AnalysisMode.ALL;
         this.environment = env;
         this.synonymsManagementAPIService = synonymsManagementAPIService;
-        this.threadPool = threadPool;
     }
 
     @Override
@@ -88,13 +84,14 @@ public class SynonymTokenFilterFactory extends AbstractTokenFilterFactory {
 
     @Override
     public TokenFilterFactory getChainAwareTokenFilterFactory(
+        IndexCreationContext context,
         TokenizerFactory tokenizer,
         List<CharFilterFactory> charFilters,
         List<TokenFilterFactory> previousTokenFilters,
         Function<String, TokenFilterFactory> allFilters
     ) {
         final Analyzer analyzer = buildSynonymAnalyzer(tokenizer, charFilters, previousTokenFilters);
-        ReaderWithOrigin rulesFromSettings = getRulesFromSettings(environment);
+        ReaderWithOrigin rulesFromSettings = getRulesFromSettings(environment, context);
         final SynonymMap synonyms = buildSynonyms(analyzer, rulesFromSettings);
         final String name = name();
         return new TokenFilterFactory() {
@@ -156,7 +153,7 @@ public class SynonymTokenFilterFactory extends AbstractTokenFilterFactory {
         }
     }
 
-    protected ReaderWithOrigin getRulesFromSettings(Environment env) {
+    protected ReaderWithOrigin getRulesFromSettings(Environment env, IndexCreationContext context) {
         if (settings.getAsList("synonyms", null) != null) {
             List<String> rulesList = Analysis.getWordList(env, settings, "synonyms");
             StringBuilder sb = new StringBuilder();
@@ -171,15 +168,17 @@ public class SynonymTokenFilterFactory extends AbstractTokenFilterFactory {
                 );
             }
             String synonymsSet = settings.get("synonyms_set", null);
-            // provide fake synonyms on master thread, as on Master an analyzer is built for validation only
+            // provide fake synonyms on index creation and index metadata checks to ensure that we
-            if (MasterService.isMasterUpdateThread()) {
+            // don't block a master thread
+            if (context != IndexCreationContext.RELOAD_ANALYZERS) {
                 return new ReaderWithOrigin(
                     new StringReader("fake rule => fake"),
-                    "fake [" + synonymsSet + "] synonyms_set in .synonyms index"
+                    "fake [" + synonymsSet + "] synonyms_set in .synonyms index",
+                    synonymsSet
                 );
             }
             return new ReaderWithOrigin(
-                Analysis.getReaderFromIndex(synonymsSet, threadPool, synonymsManagementAPIService),
+                Analysis.getReaderFromIndex(synonymsSet, synonymsManagementAPIService),
                 "[" + synonymsSet + "] synonyms_set in .synonyms index",
                 synonymsSet
             );

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/CompoundAnalysisTests.java

@@ -16,6 +16,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.analysis.MyFilterTokenFilterFactory;
@@ -64,7 +65,7 @@ public class CompoundAnalysisTests extends ESTestCase {
     private List<String> analyze(Settings settings, String analyzerName, String text) throws IOException {
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("test", settings);
         AnalysisModule analysisModule = createAnalysisModule(settings);
-        IndexAnalyzers indexAnalyzers = analysisModule.getAnalysisRegistry().build(idxSettings);
+        IndexAnalyzers indexAnalyzers = analysisModule.getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
         Analyzer analyzer = indexAnalyzers.get(analyzerName).analyzer();
 
         TokenStream stream = analyzer.tokenStream("", text);

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/EdgeNGramTokenizerTests.java

@@ -15,6 +15,7 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.analysis.NamedAnalyzer;
@@ -41,7 +42,7 @@ public class EdgeNGramTokenizerTests extends ESTokenStreamTestCase {
             TestEnvironment.newEnvironment(settings),
             Collections.singletonList(new CommonAnalysisPlugin()),
             new StablePluginsRegistry()
-        ).getAnalysisRegistry().build(idxSettings);
+        ).getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
     }
 
     public void testPreConfiguredTokenizer() throws IOException {

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/MultiplexerTokenFilterTests.java

@@ -13,6 +13,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.analysis.NamedAnalyzer;
@@ -44,7 +45,7 @@ public class MultiplexerTokenFilterTests extends ESTokenStreamTestCase {
             TestEnvironment.newEnvironment(settings),
             Collections.singletonList(new CommonAnalysisPlugin()),
             new StablePluginsRegistry()
-        ).getAnalysisRegistry().build(idxSettings);
+        ).getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
 
         try (NamedAnalyzer analyzer = indexAnalyzers.get("myAnalyzer")) {
             assertNotNull(analyzer);
@@ -79,7 +80,7 @@ public class MultiplexerTokenFilterTests extends ESTokenStreamTestCase {
             TestEnvironment.newEnvironment(settings),
             Collections.singletonList(new CommonAnalysisPlugin()),
             new StablePluginsRegistry()
-        ).getAnalysisRegistry().build(idxSettings);
+        ).getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
 
         try (NamedAnalyzer analyzer = indexAnalyzers.get("myAnalyzer")) {
             assertNotNull(analyzer);

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/PredicateTokenScriptFilterTests.java

@@ -19,6 +19,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.analysis.NamedAnalyzer;
@@ -74,7 +75,7 @@ public class PredicateTokenScriptFilterTests extends ESTokenStreamTestCase {
             new StablePluginsRegistry()
         );
 
-        IndexAnalyzers analyzers = module.getAnalysisRegistry().build(idxSettings);
+        IndexAnalyzers analyzers = module.getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
 
         try (NamedAnalyzer analyzer = analyzers.get("myAnalyzer")) {
             assertNotNull(analyzer);

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/ScriptedConditionTokenFilterTests.java

@@ -19,6 +19,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.analysis.NamedAnalyzer;
@@ -74,7 +75,7 @@ public class ScriptedConditionTokenFilterTests extends ESTokenStreamTestCase {
             new StablePluginsRegistry()
         );
 
-        IndexAnalyzers analyzers = module.getAnalysisRegistry().build(idxSettings);
+        IndexAnalyzers analyzers = module.getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
 
         try (NamedAnalyzer analyzer = analyzers.get("myAnalyzer")) {
             assertNotNull(analyzer);

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/SynonymsAnalysisTests.java

@@ -268,7 +268,7 @@ public class SynonymsAnalysisTests extends ESTestCase {
         for (String factory : bypassingFactories) {
             TokenFilterFactory tff = plugin.getTokenFilters().get(factory).get(idxSettings, null, factory, settings);
             TokenizerFactory tok = new KeywordTokenizerFactory(idxSettings, null, "keyword", settings);
-            SynonymTokenFilterFactory stff = new SynonymTokenFilterFactory(idxSettings, null, "synonym", settings, null, null);
+            SynonymTokenFilterFactory stff = new SynonymTokenFilterFactory(idxSettings, null, "synonym", settings, null);
             Analyzer analyzer = SynonymTokenFilterFactory.buildSynonymAnalyzer(
                 tok,
                 Collections.emptyList(),
@@ -338,7 +338,7 @@ public class SynonymsAnalysisTests extends ESTestCase {
         for (String factory : disallowedFactories) {
             TokenFilterFactory tff = plugin.getTokenFilters().get(factory).get(idxSettings, null, factory, settings);
             TokenizerFactory tok = new KeywordTokenizerFactory(idxSettings, null, "keyword", settings);
-            SynonymTokenFilterFactory stff = new SynonymTokenFilterFactory(idxSettings, null, "synonym", settings, null, null);
+            SynonymTokenFilterFactory stff = new SynonymTokenFilterFactory(idxSettings, null, "synonym", settings, null);
 
             IllegalArgumentException e = expectThrows(
                 IllegalArgumentException.class,

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/WordDelimiterGraphTokenFilterFactoryTests.java

@@ -14,6 +14,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisTestsHelper;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
@@ -196,7 +197,7 @@ public class WordDelimiterGraphTokenFilterFactoryTests extends BaseWordDelimiter
                     TestEnvironment.newEnvironment(settings),
                     Collections.singletonList(new CommonAnalysisPlugin()),
                     new StablePluginsRegistry()
-                ).getAnalysisRegistry().build(idxSettings)
+                ).getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings)
             ) {
 
                 NamedAnalyzer analyzer = indexAnalyzers.get("my_analyzer");
@@ -221,7 +222,7 @@ public class WordDelimiterGraphTokenFilterFactoryTests extends BaseWordDelimiter
                     TestEnvironment.newEnvironment(settings),
                     Collections.singletonList(new CommonAnalysisPlugin()),
                     new StablePluginsRegistry()
-                ).getAnalysisRegistry().build(idxSettings)
+                ).getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings)
             ) {
 
                 NamedAnalyzer analyzer = indexAnalyzers.get("my_analyzer");

modules/analysis-common/src/yamlRestTest/resources/rest-api-spec/test/analysis-common/70_synonyms_from_index.yml

@@ -141,6 +141,25 @@ setup:
                 query: bye
   - match: { hits.total.value: 1 }
 
+  - do:
+      indices.close:
+        index: my_index
+
+  - do:
+      indices.open:
+        index: my_index
+
+  # Confirm that the index analyzers are reloaded
+  - do:
+      search:
+        index: my_index
+        body:
+          query:
+            match:
+              my_field:
+                query: hola
+  - match: { hits.total.value: 1 }
+
 ---
 "Delete the synonyms set and confirm failed reload analyzers details":
   - do:

server/src/main/java/org/elasticsearch/action/admin/indices/analyze/TransportAnalyzeAction.java

@@ -29,6 +29,7 @@ import org.elasticsearch.common.io.stream.Writeable;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.IOUtils;
 import org.elasticsearch.index.IndexService;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.analysis.AnalyzerComponents;
@@ -212,6 +213,7 @@ public class TransportAnalyzeAction extends TransportSingleShardAction<AnalyzeAc
     ) throws IOException {
         if (request.tokenizer() != null) {
             return analysisRegistry.buildCustomAnalyzer(
+                IndexCreationContext.RELOAD_ANALYZERS,
                 indexSettings,
                 false,
                 request.tokenizer(),
@@ -221,6 +223,7 @@ public class TransportAnalyzeAction extends TransportSingleShardAction<AnalyzeAc
         } else if (((request.tokenFilters() != null && request.tokenFilters().size() > 0)
             || (request.charFilters() != null && request.charFilters().size() > 0))) {
                 return analysisRegistry.buildCustomAnalyzer(
+                    IndexCreationContext.RELOAD_ANALYZERS,
                     indexSettings,
                     true,
                     new NameOrDefinition("keyword"),

server/src/main/java/org/elasticsearch/index/IndexModule.java

@@ -35,6 +35,7 @@ import org.elasticsearch.core.CheckedFunction;
 import org.elasticsearch.core.IOUtils;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.env.NodeEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.cache.query.DisabledQueryCache;
@@ -456,7 +457,7 @@ public final class IndexModule {
     }
 
     public IndexService newIndexService(
-        IndexService.IndexCreationContext indexCreationContext,
+        IndexCreationContext indexCreationContext,
         NodeEnvironment environment,
         XContentParserConfiguration parserConfiguration,
         IndexService.ShardStoreDeleter shardStoreDeleter,
@@ -501,7 +502,7 @@ public final class IndexModule {
                 queryCache = DisabledQueryCache.INSTANCE;
             }
             if (IndexService.needsMapperService(indexSettings, indexCreationContext)) {
-                indexAnalyzers = analysisRegistry.build(indexSettings);
+                indexAnalyzers = analysisRegistry.build(indexCreationContext, indexSettings);
             }
             final IndexService indexService = new IndexService(
                 indexSettings,
@@ -636,7 +637,7 @@ public final class IndexModule {
         return new MapperService(
             clusterService,
             indexSettings,
-            analysisRegistry.build(indexSettings),
+            analysisRegistry.build(IndexCreationContext.METADATA_VERIFICATION, indexSettings),
             parserConfiguration,
             new SimilarityService(indexSettings, scriptService, similarities),
             mapperRegistry,

server/src/main/java/org/elasticsearch/index/IndexService.java

@@ -190,6 +190,8 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
         Engine.IndexCommitListener indexCommitListener
     ) {
         super(indexSettings);
+        assert indexCreationContext != IndexCreationContext.RELOAD_ANALYZERS
+            : "IndexCreationContext.RELOAD_ANALYZERS should only be used when reloading analysers";
         this.allowExpensiveQueries = allowExpensiveQueries;
         this.indexSettings = indexSettings;
         this.parserConfiguration = parserConfiguration;
@@ -274,7 +276,8 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
 
     public enum IndexCreationContext {
         CREATE_INDEX,
-        METADATA_VERIFICATION
+        METADATA_VERIFICATION,
+        RELOAD_ANALYZERS
     }
 
     public int numberOfShards() {

server/src/main/java/org/elasticsearch/index/analysis/Analysis.java

@@ -52,7 +52,6 @@ import org.elasticsearch.env.Environment;
 import org.elasticsearch.synonyms.PagedResult;
 import org.elasticsearch.synonyms.SynonymRule;
 import org.elasticsearch.synonyms.SynonymsManagementAPIService;
-import org.elasticsearch.threadpool.ThreadPool;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -298,22 +297,9 @@ public class Analysis {
         }
     }
 
-    public static Reader getReaderFromIndex(
+    public static Reader getReaderFromIndex(String synonymsSet, SynonymsManagementAPIService synonymsManagementAPIService) {
-        String synonymsSet,
+        final PlainActionFuture<PagedResult<SynonymRule>> synonymsLoadingFuture = new PlainActionFuture<>();
-        ThreadPool threadPool,
-        SynonymsManagementAPIService synonymsManagementAPIService
-    ) {
-        // TODO: this is a temporary solution for loading synonyms under feature flag, to be redesigned for GA
-        final PlainActionFuture<PagedResult<SynonymRule>> synonymsLoadingFuture = new PlainActionFuture<>() {
-            @Override
-            protected boolean blockingAllowed() {
-                // allow blocking while loading synonyms under feature flag
-                return true;
-            }
-        };
-        threadPool.executor(ThreadPool.Names.SYSTEM_READ).execute(() -> {
         synonymsManagementAPIService.getSynonymSetRules(synonymsSet, 0, 10_000, synonymsLoadingFuture);
-        });
         PagedResult<SynonymRule> results = synonymsLoadingFuture.actionGet();
 
         SynonymRule[] synonymRules = results.pageResults();

server/src/main/java/org/elasticsearch/index/analysis/AnalysisRegistry.java

@@ -17,6 +17,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.IOUtils;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.TextFieldMapper;
 import org.elasticsearch.indices.analysis.AnalysisModule;
@@ -41,7 +42,7 @@ import static java.util.Collections.unmodifiableMap;
 
 /**
  * An internal registry for tokenizer, token filter, char filter and analyzer.
- * This class exists per node and allows to create per-index {@link IndexAnalyzers} via {@link #build(IndexSettings)}
+ * This class exists per node and allows to create per-index {@link IndexAnalyzers} via {@link #build}
  */
 public final class AnalysisRegistry implements Closeable {
     public static final String INDEX_ANALYSIS_CHAR_FILTER = "index.analysis.char_filter";
@@ -201,14 +202,23 @@ public final class AnalysisRegistry implements Closeable {
 
     /**
      * Creates an index-level {@link IndexAnalyzers} from this registry using the given index settings
+     * and {@link IndexCreationContext}.
      */
-    public IndexAnalyzers build(IndexSettings indexSettings) throws IOException {
+    public IndexAnalyzers build(IndexCreationContext context, IndexSettings indexSettings) throws IOException {
         final Map<String, CharFilterFactory> charFilterFactories = buildCharFilterFactories(indexSettings);
         final Map<String, TokenizerFactory> tokenizerFactories = buildTokenizerFactories(indexSettings);
         final Map<String, TokenFilterFactory> tokenFilterFactories = buildTokenFilterFactories(indexSettings);
         final Map<String, AnalyzerProvider<?>> analyzerFactories = buildAnalyzerFactories(indexSettings);
         final Map<String, AnalyzerProvider<?>> normalizerFactories = buildNormalizerFactories(indexSettings);
-        return build(indexSettings, analyzerFactories, normalizerFactories, tokenizerFactories, charFilterFactories, tokenFilterFactories);
+        return build(
+            context,
+            indexSettings,
+            analyzerFactories,
+            normalizerFactories,
+            tokenizerFactories,
+            charFilterFactories,
+            tokenFilterFactories
+        );
     }
 
     /**
@@ -217,6 +227,7 @@ public final class AnalysisRegistry implements Closeable {
      * Callers are responsible for closing the returned Analyzer
      */
     public NamedAnalyzer buildCustomAnalyzer(
+        IndexCreationContext context,
         IndexSettings indexSettings,
         boolean normalizer,
         NameOrDefinition tokenizer,
@@ -259,7 +270,7 @@ public final class AnalysisRegistry implements Closeable {
             if (normalizer && tff instanceof NormalizingTokenFilterFactory == false) {
                 throw new IllegalArgumentException("Custom normalizer may not use filter [" + tff.name() + "]");
             }
-            tff = tff.getChainAwareTokenFilterFactory(tokenizerFactory, charFilterFactories, tokenFilterFactories, name -> {
+            tff = tff.getChainAwareTokenFilterFactory(context, tokenizerFactory, charFilterFactories, tokenFilterFactories, name -> {
                 try {
                     return getComponentFactory(
                         indexSettings,
@@ -281,7 +292,7 @@ public final class AnalysisRegistry implements Closeable {
             charFilterFactories.toArray(new CharFilterFactory[] {}),
             tokenFilterFactories.toArray(new TokenFilterFactory[] {})
         );
-        return produceAnalyzer("__custom__", new AnalyzerProvider<>() {
+        return produceAnalyzer(context, "__custom__", new AnalyzerProvider<>() {
             @Override
             public String name() {
                 return "__custom__";
@@ -589,6 +600,7 @@ public final class AnalysisRegistry implements Closeable {
     }
 
     public static IndexAnalyzers build(
+        IndexCreationContext context,
         IndexSettings indexSettings,
         Map<String, AnalyzerProvider<?>> analyzerProviders,
         Map<String, AnalyzerProvider<?>> normalizerProviders,
@@ -603,6 +615,7 @@ public final class AnalysisRegistry implements Closeable {
             analyzers.merge(
                 entry.getKey(),
                 produceAnalyzer(
+                    context,
                     entry.getKey(),
                     entry.getValue(),
                     tokenFilterFactoryFactories,
@@ -641,6 +654,7 @@ public final class AnalysisRegistry implements Closeable {
             analyzers.put(
                 DEFAULT_ANALYZER_NAME,
                 produceAnalyzer(
+                    context,
                     DEFAULT_ANALYZER_NAME,
                     new StandardAnalyzerProvider(indexSettings, null, DEFAULT_ANALYZER_NAME, Settings.EMPTY),
                     tokenFilterFactoryFactories,
@@ -677,6 +691,7 @@ public final class AnalysisRegistry implements Closeable {
     }
 
     private static NamedAnalyzer produceAnalyzer(
+        IndexCreationContext context,
         String name,
         AnalyzerProvider<?> analyzerFactory,
         Map<String, TokenFilterFactory> tokenFilters,
@@ -691,7 +706,7 @@ public final class AnalysisRegistry implements Closeable {
          */
         int overridePositionIncrementGap = TextFieldMapper.Defaults.POSITION_INCREMENT_GAP;
         if (analyzerFactory instanceof CustomAnalyzerProvider) {
-            ((CustomAnalyzerProvider) analyzerFactory).build(tokenizers, charFilters, tokenFilters);
+            ((CustomAnalyzerProvider) analyzerFactory).build(context, tokenizers, charFilters, tokenFilters);
             /*
              * Custom analyzers already default to the correct, version
              * dependent positionIncrementGap and the user is be able to

server/src/main/java/org/elasticsearch/index/analysis/AnalyzerComponents.java

@@ -9,6 +9,7 @@
 package org.elasticsearch.index.analysis;
 
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -38,6 +39,7 @@ public final class AnalyzerComponents {
     }
 
     static AnalyzerComponents createComponents(
+        IndexCreationContext context,
         String name,
         Settings analyzerSettings,
         final Map<String, TokenizerFactory> tokenizers,
@@ -77,7 +79,13 @@ public final class AnalyzerComponents {
                     "Custom Analyzer [" + name + "] failed to find filter under name " + "[" + tokenFilterName + "]"
                 );
             }
-            tokenFilter = tokenFilter.getChainAwareTokenFilterFactory(tokenizer, charFiltersList, tokenFilterList, tokenFilters::get);
+            tokenFilter = tokenFilter.getChainAwareTokenFilterFactory(
+                context,
+                tokenizer,
+                charFiltersList,
+                tokenFilterList,
+                tokenFilters::get
+            );
             tokenFilterList.add(tokenFilter);
         }
 

server/src/main/java/org/elasticsearch/index/analysis/CustomAnalyzerProvider.java

@@ -10,6 +10,7 @@ package org.elasticsearch.index.analysis;
 
 import org.apache.lucene.analysis.Analyzer;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.TextFieldMapper;
 
@@ -33,11 +34,12 @@ public class CustomAnalyzerProvider extends AbstractIndexAnalyzerProvider<Analyz
     }
 
     void build(
+        final IndexCreationContext context,
         final Map<String, TokenizerFactory> tokenizers,
         final Map<String, CharFilterFactory> charFilters,
         final Map<String, TokenFilterFactory> tokenFilters
     ) {
-        customAnalyzer = create(name(), analyzerSettings, tokenizers, charFilters, tokenFilters);
+        customAnalyzer = create(context, name(), analyzerSettings, tokenizers, charFilters, tokenFilters);
     }
 
     /**
@@ -45,6 +47,7 @@ public class CustomAnalyzerProvider extends AbstractIndexAnalyzerProvider<Analyz
      * and search time use, or a {@link ReloadableCustomAnalyzer} if the components are intended for search time use only.
      */
     private static Analyzer create(
+        IndexCreationContext context,
         String name,
         Settings analyzerSettings,
         Map<String, TokenizerFactory> tokenizers,
@@ -54,7 +57,7 @@ public class CustomAnalyzerProvider extends AbstractIndexAnalyzerProvider<Analyz
         int positionIncrementGap = TextFieldMapper.Defaults.POSITION_INCREMENT_GAP;
         positionIncrementGap = analyzerSettings.getAsInt("position_increment_gap", positionIncrementGap);
         int offsetGap = analyzerSettings.getAsInt("offset_gap", -1);
-        AnalyzerComponents components = createComponents(name, analyzerSettings, tokenizers, charFilters, tokenFilters);
+        AnalyzerComponents components = createComponents(context, name, analyzerSettings, tokenizers, charFilters, tokenFilters);
         if (components.analysisMode().equals(AnalysisMode.SEARCH_TIME)) {
             return new ReloadableCustomAnalyzer(components, positionIncrementGap, offsetGap);
         } else {

server/src/main/java/org/elasticsearch/index/analysis/ReloadableCustomAnalyzer.java

@@ -14,6 +14,7 @@ import org.apache.lucene.analysis.Tokenizer;
 import org.apache.lucene.util.CloseableThreadLocal;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.CollectionUtils;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 
 import java.io.Reader;
 import java.util.HashSet;
@@ -136,7 +137,14 @@ public final class ReloadableCustomAnalyzer extends Analyzer implements Analyzer
         final Map<String, CharFilterFactory> charFilters,
         final Map<String, TokenFilterFactory> tokenFilters
     ) {
-        AnalyzerComponents components = AnalyzerComponents.createComponents(name, settings, tokenizers, charFilters, tokenFilters);
+        AnalyzerComponents components = AnalyzerComponents.createComponents(
+            IndexCreationContext.RELOAD_ANALYZERS,
+            name,
+            settings,
+            tokenizers,
+            charFilters,
+            tokenFilters
+        );
         this.components = components;
     }
 

server/src/main/java/org/elasticsearch/index/analysis/TokenFilterFactory.java

@@ -9,7 +9,9 @@
 package org.elasticsearch.index.analysis;
 
 import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.synonym.SynonymGraphFilterFactory;
 import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.search.fetch.subphase.highlight.FastVectorHighlighter;
 
 import java.util.List;
@@ -41,12 +43,20 @@ public interface TokenFilterFactory {
     /**
      * Rewrite the TokenFilterFactory to take into account the preceding analysis chain, or refer
      * to other TokenFilterFactories
+     * If the token filter is part of the definition of a  {@link ReloadableCustomAnalyzer},
+     * this function is called twice, once at index creation with {@link IndexCreationContext#CREATE_INDEX}
+     * and then later with {@link IndexCreationContext#RELOAD_ANALYZERS} on shard recovery.
+     * The {@link IndexCreationContext#RELOAD_ANALYZERS} context should be used to load expensive resources
+     * on a generic thread pool. See {@link SynonymGraphFilterFactory} for an example of how this context
+     * is used.
+     * @param context               the IndexCreationContext for the underlying index
      * @param tokenizer             the TokenizerFactory for the preceding chain
      * @param charFilters           any CharFilterFactories for the preceding chain
      * @param previousTokenFilters  a list of TokenFilterFactories in the preceding chain
      * @param allFilters            access to previously defined TokenFilterFactories
      */
     default TokenFilterFactory getChainAwareTokenFilterFactory(
+        IndexCreationContext context,
         TokenizerFactory tokenizer,
         List<CharFilterFactory> charFilters,
         List<TokenFilterFactory> previousTokenFilters,

server/src/main/java/org/elasticsearch/index/mapper/MapperService.java

@@ -17,6 +17,7 @@ import org.elasticsearch.common.compress.CompressorFactory;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
+import org.elasticsearch.core.Nullable;
 import org.elasticsearch.index.AbstractIndexComponent;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
@@ -525,7 +526,15 @@ public class MapperService extends AbstractIndexComponent implements Closeable {
         return mappingLookup().isMultiField(field);
     }
 
-    public synchronized List<String> reloadSearchAnalyzers(AnalysisRegistry registry, String resource) throws IOException {
+    /**
+     * Reload any search analyzers that have reloadable components if resource is {@code null},
+     * otherwise only the provided resource is reloaded.
+     * @param registry the analysis registry
+     * @param resource the name of the reloadable resource or {@code null} if all resources should be reloaded.
+     * @return The names of reloaded resources.
+     * @throws IOException
+     */
+    public synchronized List<String> reloadSearchAnalyzers(AnalysisRegistry registry, @Nullable String resource) throws IOException {
         logger.info("reloading search analyzers");
         // TODO this should bust the cache somehow. Tracked in https://github.com/elastic/elasticsearch/issues/66722
         return indexAnalyzers.reload(registry, indexSettings, resource);

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

@@ -18,6 +18,7 @@ import org.apache.lucene.util.RamUsageEstimator;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ResourceAlreadyExistsException;
 import org.elasticsearch.Version;
+import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.admin.indices.mapping.put.AutoPutMappingAction;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingAction;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
@@ -626,8 +627,35 @@ public class IndicesService extends AbstractLifecycleComponent
                 }
             }
         };
+        final IndexEventListener beforeIndexShardRecovery = new IndexEventListener() {
+            volatile boolean reloaded;
+
+            @Override
+            public void beforeIndexShardRecovery(IndexShard indexShard, IndexSettings indexSettings, ActionListener<Void> listener) {
+                try {
+                    if (indexShard.mapperService() != null) {
+                        // we need to reload once, not on every shard recovery in case multiple shards are on the same node
+                        if (reloaded == false) {
+                            synchronized (indexShard.mapperService()) {
+                                if (reloaded == false) {
+                                    // we finish loading analyzers from resources here
+                                    // during shard recovery in the generic thread pool,
+                                    // as this may require longer running operations and blocking calls
+                                    indexShard.mapperService().reloadSearchAnalyzers(getAnalysis(), null);
+                                }
+                                reloaded = true;
+                            }
+                        }
+                    }
+                    listener.onResponse(null);
+                } catch (Exception e) {
+                    listener.onFailure(e);
+                }
+            }
+        };
         finalListeners.add(onStoreClose);
         finalListeners.add(oldShardsStats);
+        finalListeners.add(beforeIndexShardRecovery);
         IndexService indexService;
         try (var ignored = threadPool.getThreadContext().newStoredContext()) {
             indexService = createIndexService(

server/src/main/java/org/elasticsearch/search/aggregations/support/AggregationContext.java

@@ -20,6 +20,7 @@ import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.core.Releasable;
 import org.elasticsearch.core.Releasables;
+import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.analysis.NameOrDefinition;
@@ -443,7 +444,14 @@ public abstract class AggregationContext implements Releasable {
             List<NameOrDefinition> charFilters,
             List<NameOrDefinition> tokenFilters
         ) throws IOException {
-            return analysisRegistry.buildCustomAnalyzer(indexSettings, normalizer, tokenizer, charFilters, tokenFilters);
+            return analysisRegistry.buildCustomAnalyzer(
+                IndexService.IndexCreationContext.RELOAD_ANALYZERS,
+                indexSettings,
+                normalizer,
+                tokenizer,
+                charFilters,
+                tokenFilters
+            );
         }
 
         @Override

server/src/test/java/org/elasticsearch/action/admin/indices/TransportAnalyzeActionTests.java

@@ -140,7 +140,7 @@ public class TransportAnalyzeActionTests extends ESTestCase {
             }
         };
         registry = new AnalysisModule(environment, singletonList(plugin), new StablePluginsRegistry()).getAnalysisRegistry();
-        indexAnalyzers = registry.build(this.indexSettings);
+        indexAnalyzers = registry.build(IndexService.IndexCreationContext.RELOAD_ANALYZERS, this.indexSettings);
         maxTokenCount = IndexSettings.MAX_TOKEN_COUNT_SETTING.getDefault(settings);
         idxMaxTokenCount = this.indexSettings.getMaxTokenCount();
     }

server/src/test/java/org/elasticsearch/index/analysis/AnalysisRegistryTests.java

@@ -24,6 +24,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.MapperException;
 import org.elasticsearch.indices.analysis.AnalysisModule;
@@ -107,7 +108,7 @@ public class AnalysisRegistryTests extends ESTestCase {
             .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toString())
             .build();
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("index", settings);
-        IndexAnalyzers indexAnalyzers = emptyRegistry.build(idxSettings);
+        IndexAnalyzers indexAnalyzers = emptyRegistry.build(IndexCreationContext.CREATE_INDEX, idxSettings);
         assertThat(indexAnalyzers.getDefaultIndexAnalyzer().analyzer(), instanceOf(StandardAnalyzer.class));
         assertThat(indexAnalyzers.getDefaultSearchAnalyzer().analyzer(), instanceOf(StandardAnalyzer.class));
         assertThat(indexAnalyzers.getDefaultSearchQuoteAnalyzer().analyzer(), instanceOf(StandardAnalyzer.class));
@@ -118,6 +119,7 @@ public class AnalysisRegistryTests extends ESTestCase {
         Version version = VersionUtils.randomVersion(random());
         Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
         IndexAnalyzers indexAnalyzers = AnalysisRegistry.build(
+            IndexCreationContext.CREATE_INDEX,
             IndexSettingsModule.newIndexSettings("index", settings),
             singletonMap("default", analyzerProvider("default")),
             emptyMap(),
@@ -155,6 +157,7 @@ public class AnalysisRegistryTests extends ESTestCase {
         MapperException ex = expectThrows(
             MapperException.class,
             () -> AnalysisRegistry.build(
+                IndexCreationContext.CREATE_INDEX,
                 IndexSettingsModule.newIndexSettings("index", settings),
                 singletonMap("default", new PreBuiltAnalyzerProvider("default", AnalyzerScope.INDEX, analyzer)),
                 emptyMap(),
@@ -169,7 +172,10 @@ public class AnalysisRegistryTests extends ESTestCase {
     public void testNameClashNormalizer() throws IOException {
 
         // Test out-of-the-box normalizer works OK.
-        IndexAnalyzers indexAnalyzers = nonEmptyRegistry.build(IndexSettingsModule.newIndexSettings("index", Settings.EMPTY));
+        IndexAnalyzers indexAnalyzers = nonEmptyRegistry.build(
+            IndexCreationContext.CREATE_INDEX,
+            IndexSettingsModule.newIndexSettings("index", Settings.EMPTY)
+        );
         assertNotNull(indexAnalyzers.getNormalizer("lowercase"));
         assertThat(indexAnalyzers.getNormalizer("lowercase").normalize("field", "AbC").utf8ToString(), equalTo("abc"));
 
@@ -181,7 +187,7 @@ public class AnalysisRegistryTests extends ESTestCase {
             .putList("index.analysis.normalizer.lowercase.filter", "reverse")
             .build();
 
-        indexAnalyzers = nonEmptyRegistry.build(IndexSettingsModule.newIndexSettings("index", settings));
+        indexAnalyzers = nonEmptyRegistry.build(IndexCreationContext.CREATE_INDEX, IndexSettingsModule.newIndexSettings("index", settings));
         assertNotNull(indexAnalyzers.getNormalizer("lowercase"));
         assertThat(indexAnalyzers.getNormalizer("lowercase").normalize("field", "AbC").utf8ToString(), equalTo("CbA"));
     }
@@ -193,6 +199,7 @@ public class AnalysisRegistryTests extends ESTestCase {
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
             () -> AnalysisRegistry.build(
+                IndexCreationContext.CREATE_INDEX,
                 IndexSettingsModule.newIndexSettings("index", settings),
                 singletonMap("default_index", defaultIndex),
                 emptyMap(),
@@ -208,6 +215,7 @@ public class AnalysisRegistryTests extends ESTestCase {
         Version version = VersionUtils.randomVersion(random());
         Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
         IndexAnalyzers indexAnalyzers = AnalysisRegistry.build(
+            IndexCreationContext.CREATE_INDEX,
             IndexSettingsModule.newIndexSettings("index", settings),
             singletonMap("default_search", analyzerProvider("default_search")),
             emptyMap(),
@@ -263,7 +271,7 @@ public class AnalysisRegistryTests extends ESTestCase {
             TestEnvironment.newEnvironment(settings),
             singletonList(plugin),
             new StablePluginsRegistry()
-        ).getAnalysisRegistry().build(idxSettings);
+        ).getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
 
         // This shouldn't contain English stopwords
         try (NamedAnalyzer custom_analyser = indexAnalyzers.get("custom_analyzer_with_camel_case")) {
@@ -298,8 +306,8 @@ public class AnalysisRegistryTests extends ESTestCase {
         Settings settings = Settings.builder().put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toString()).build();
         Settings indexSettings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build();
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("index", indexSettings);
-        IndexAnalyzers indexAnalyzers = emptyAnalysisRegistry(settings).build(idxSettings);
+        IndexAnalyzers indexAnalyzers = emptyAnalysisRegistry(settings).build(IndexCreationContext.CREATE_INDEX, idxSettings);
-        IndexAnalyzers otherIndexAnalyzers = emptyAnalysisRegistry(settings).build(idxSettings);
+        IndexAnalyzers otherIndexAnalyzers = emptyAnalysisRegistry(settings).build(IndexCreationContext.CREATE_INDEX, idxSettings);
         final int numIters = randomIntBetween(5, 20);
         for (int i = 0; i < numIters; i++) {
             PreBuiltAnalyzers preBuiltAnalyzers = RandomPicks.randomFrom(random(), PreBuiltAnalyzers.values());
@@ -317,12 +325,18 @@ public class AnalysisRegistryTests extends ESTestCase {
             .build();
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("index", settings);
 
-        IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> emptyAnalysisRegistry(settings).build(idxSettings));
+        IllegalArgumentException e = expectThrows(
+            IllegalArgumentException.class,
+            () -> emptyAnalysisRegistry(settings).build(IndexCreationContext.CREATE_INDEX, idxSettings)
+        );
         assertThat(e.getMessage(), equalTo("analyzer [test_analyzer] must specify either an analyzer type, or a tokenizer"));
     }
 
     public void testCloseIndexAnalyzersMultipleTimes() throws IOException {
-        IndexAnalyzers indexAnalyzers = emptyRegistry.build(indexSettingsOfCurrentVersion(Settings.builder()));
+        IndexAnalyzers indexAnalyzers = emptyRegistry.build(
+            IndexCreationContext.CREATE_INDEX,
+            indexSettingsOfCurrentVersion(Settings.builder())
+        );
         indexAnalyzers.close();
         indexAnalyzers.close();
     }

server/src/test/java/org/elasticsearch/index/analysis/ReloadableCustomAnalyzerTests.java

@@ -16,6 +16,7 @@ import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.test.ESTestCase;
 import org.junit.BeforeClass;
 
@@ -72,6 +73,7 @@ public class ReloadableCustomAnalyzerTests extends ESTestCase {
         Settings analyzerSettings = Settings.builder().put("tokenizer", "standard").putList("filter", "my_filter").build();
 
         AnalyzerComponents components = createComponents(
+            IndexCreationContext.CREATE_INDEX,
             "my_analyzer",
             analyzerSettings,
             testAnalysis.tokenizer,
@@ -92,6 +94,7 @@ public class ReloadableCustomAnalyzerTests extends ESTestCase {
         // check that when using regular non-search time filters only, we get an exception
         final Settings indexAnalyzerSettings = Settings.builder().put("tokenizer", "standard").putList("filter", "lowercase").build();
         AnalyzerComponents indexAnalyzerComponents = createComponents(
+            IndexCreationContext.CREATE_INDEX,
             "my_analyzer",
             indexAnalyzerSettings,
             testAnalysis.tokenizer,
@@ -115,6 +118,7 @@ public class ReloadableCustomAnalyzerTests extends ESTestCase {
         Settings analyzerSettings = Settings.builder().put("tokenizer", "standard").putList("filter", "my_filter").build();
 
         AnalyzerComponents components = createComponents(
+            IndexCreationContext.RELOAD_ANALYZERS,
             "my_analyzer",
             analyzerSettings,
             testAnalysis.tokenizer,

server/src/test/java/org/elasticsearch/indices/analysis/AnalysisModuleTests.java

@@ -19,6 +19,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.index.analysis.Analysis;
@@ -75,7 +76,7 @@ public class AnalysisModuleTests extends ESTestCase {
 
     public IndexAnalyzers getIndexAnalyzers(AnalysisRegistry registry, Settings settings) throws IOException {
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("test", settings);
-        return registry.build(idxSettings);
+        return registry.build(IndexCreationContext.CREATE_INDEX, idxSettings);
     }
 
     public AnalysisRegistry getNewRegistry(Settings settings) {

server/src/test/java/org/elasticsearch/indices/analysis/IncorrectSetupStablePluginsTests.java

@@ -12,6 +12,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
@@ -122,7 +123,7 @@ public class IncorrectSetupStablePluginsTests extends ESTestCase {
         AnalysisRegistry registry = setupRegistry(mapOfCharFilters);
 
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("test", settings);
-        return registry.build(idxSettings);
+        return registry.build(IndexCreationContext.CREATE_INDEX, idxSettings);
     }
 
     private AnalysisRegistry setupRegistry(Map<String, PluginInfo> mapOfCharFilters) throws IOException {

server/src/test/java/org/elasticsearch/indices/analysis/StableAnalysisPluginsNoSettingsTests.java

@@ -16,6 +16,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
@@ -55,7 +56,7 @@ public class StableAnalysisPluginsNoSettingsTests extends ESTestCase {
         AnalysisRegistry registry = setupRegistry();
 
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("test", settings);
-        return registry.build(idxSettings);
+        return registry.build(IndexCreationContext.CREATE_INDEX, idxSettings);
     }
 
     public void testStablePlugins() throws IOException {

server/src/test/java/org/elasticsearch/indices/analysis/StableAnalysisPluginsWithSettingsTests.java

@@ -15,6 +15,7 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
@@ -132,7 +133,7 @@ public class StableAnalysisPluginsWithSettingsTests extends ESTestCase {
         AnalysisRegistry registry = setupRegistry();
 
         IndexSettings idxSettings = IndexSettingsModule.newIndexSettings("test", settings);
-        return registry.build(idxSettings);
+        return registry.build(IndexCreationContext.CREATE_INDEX, idxSettings);
     }
 
     private AnalysisRegistry setupRegistry() throws IOException {

test/framework/src/main/java/org/elasticsearch/index/analysis/AnalysisTestsHelper.java

@@ -12,6 +12,7 @@ import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.indices.analysis.AnalysisModule;
 import org.elasticsearch.plugins.AnalysisPlugin;
@@ -61,7 +62,7 @@ public class AnalysisTestsHelper {
             new StablePluginsRegistry()
         ).getAnalysisRegistry();
         return new ESTestCase.TestAnalysis(
-            analysisRegistry.build(indexSettings),
+            analysisRegistry.build(IndexCreationContext.CREATE_INDEX, indexSettings),
             analysisRegistry.buildTokenFilterFactories(indexSettings),
             analysisRegistry.buildTokenizerFactories(indexSettings),
             analysisRegistry.buildCharFilterFactories(indexSettings)

test/framework/src/main/java/org/elasticsearch/test/AbstractBuilderTestCase.java

@@ -37,6 +37,7 @@ import org.elasticsearch.core.IOUtils;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.TestEnvironment;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
 import org.elasticsearch.index.cache.bitset.BitsetFilterCache;
@@ -455,7 +456,7 @@ public abstract class AbstractBuilderTestCase extends ESTestCase {
                 emptyList(),
                 new StablePluginsRegistry()
             );
-            IndexAnalyzers indexAnalyzers = analysisModule.getAnalysisRegistry().build(idxSettings);
+            IndexAnalyzers indexAnalyzers = analysisModule.getAnalysisRegistry().build(IndexCreationContext.CREATE_INDEX, idxSettings);
             scriptService = new MockScriptService(Settings.EMPTY, scriptModule.engines, scriptModule.contexts);
             similarityService = new SimilarityService(idxSettings, null, Collections.emptyMap());
             MapperRegistry mapperRegistry = indicesModule.getMapperRegistry();

test/framework/src/main/java/org/elasticsearch/test/ESTestCase.java

@@ -83,6 +83,7 @@ import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.NodeEnvironment;
 import org.elasticsearch.env.TestEnvironment;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
@@ -1749,7 +1750,7 @@ public abstract class ESTestCase extends LuceneTestCase {
         AnalysisModule analysisModule = new AnalysisModule(env, Arrays.asList(analysisPlugins), new StablePluginsRegistry());
         AnalysisRegistry analysisRegistry = analysisModule.getAnalysisRegistry();
         return new TestAnalysis(
-            analysisRegistry.build(indexSettings),
+            analysisRegistry.build(IndexCreationContext.CREATE_INDEX, indexSettings),
             analysisRegistry.buildTokenFilterFactories(indexSettings),
             analysisRegistry.buildTokenizerFactories(indexSettings),
             analysisRegistry.buildCharFilterFactories(indexSettings)

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/categorization/CategorizationAnalyzer.java

@@ -12,6 +12,7 @@ import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.core.Releasable;
 import org.elasticsearch.core.Tuple;
+import org.elasticsearch.index.IndexService.IndexCreationContext;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.xpack.core.ml.job.config.CategorizationAnalyzerConfig;
 
@@ -112,7 +113,14 @@ public class CategorizationAnalyzer implements Releasable {
             return new Tuple<>(globalAnalyzer, Boolean.FALSE);
         } else {
             return new Tuple<>(
-                analysisRegistry.buildCustomAnalyzer(null, false, config.getTokenizer(), config.getCharFilters(), config.getTokenFilters()),
+                analysisRegistry.buildCustomAnalyzer(
+                    IndexCreationContext.RELOAD_ANALYZERS,
+                    null,
+                    false,
+                    config.getTokenizer(),
+                    config.getCharFilters(),
+                    config.getTokenFilters()
+                ),
                 Boolean.TRUE
             );
         }