Remove search throttled index setting and thread pool (elastic#124874)

javanna · web-flow · commit 05e42a3cf4ad · 2025-03-15T00:15:25.000+11:00
Frozen indices, the freeze index API and the private index.frozen setting have been removed with elastic#120539. There is also a search throttled thread pool that can now be removed, as well as a private search.throttled index settings that is no longer used as it could only be set internally by freezing an index. While the index setting is private and can be removed, as it should no longer be present in any index on 9.0+ indices, the thread pool settings associated to the removed pool are still accepted as no-op in case users have customized them and are upgrading without removing these. These will also trigger a deprecating warning. This change also removes the search.throttled related output from the thread pool section of the cluster info API.
diff --git a/rest-api-spec/build.gradle b/rest-api-spec/build.gradle
@@ -108,4 +108,5 @@ tasks.named("yamlRestCompatTestTransform").configure ({ task ->
     "cluster.desired_nodes/10_basic/Test update desired nodes with node_version generates a warning",
     "node_version warning is removed in 9.0"
   )
+  task.skipTest("cluster.info/30_info_thread_pool/Cluster HTTP Info", "The search_throttled thread pool has been removed")
 })
diff --git a/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/cluster.info/30_info_thread_pool.yml b/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/cluster.info/30_info_thread_pool.yml
@@ -95,13 +95,6 @@
   - gte: { thread_pool.search_coordination.largest: 0 }
   - gte: { thread_pool.search_coordination.completed: 0 }
 
-  - gte: { thread_pool.search_throttled.threads: 0 }
-  - gte: { thread_pool.search_throttled.queue: 0 }
-  - gte: { thread_pool.search_throttled.active: 0 }
-  - gte: { thread_pool.search_throttled.rejected: 0 }
-  - gte: { thread_pool.search_throttled.largest: 0 }
-  - gte: { thread_pool.search_throttled.completed: 0 }
-
   - gte: { thread_pool.snapshot.threads: 0 }
   - gte: { thread_pool.snapshot.queue: 0 }
   - gte: { thread_pool.snapshot.active: 0 }
diff --git a/server/src/main/java/org/elasticsearch/action/explain/TransportExplainAction.java b/server/src/main/java/org/elasticsearch/action/explain/TransportExplainAction.java
@@ -44,7 +44,6 @@
 
 import java.io.IOException;
 import java.util.Set;
-import java.util.concurrent.Executor;
 import java.util.function.LongSupplier;
 
 /**
@@ -182,12 +181,4 @@ protected ShardIterator shards(ClusterState state, InternalRequest request) {
                 request.request().preference()
             );
     }
-
-    @Override
-    protected Executor getExecutor(ExplainRequest request, ShardId shardId) {
-        IndexService indexService = searchService.getIndicesService().indexServiceSafe(shardId.getIndex());
-        return indexService.getIndexSettings().isSearchThrottled()
-            ? threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED)
-            : super.getExecutor(request, shardId);
-    }
 }
diff --git a/server/src/main/java/org/elasticsearch/action/get/TransportGetAction.java b/server/src/main/java/org/elasticsearch/action/get/TransportGetAction.java
@@ -166,8 +166,6 @@ protected Executor getExecutor(GetRequest request, ShardId shardId) {
         final ClusterState clusterState = clusterService.state();
         if (clusterState.metadata().getIndexSafe(shardId.getIndex()).isSystem()) {
             return threadPool.executor(executorSelector.executorForGet(shardId.getIndexName()));
-        } else if (indicesService.indexServiceSafe(shardId.getIndex()).getIndexSettings().isSearchThrottled()) {
-            return threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED);
         } else {
             return super.getExecutor(request, shardId);
         }
diff --git a/server/src/main/java/org/elasticsearch/action/get/TransportShardMultiGetAction.java b/server/src/main/java/org/elasticsearch/action/get/TransportShardMultiGetAction.java
@@ -155,8 +155,6 @@ protected Executor getExecutor(MultiGetShardRequest request, ShardId shardId) {
         final ClusterState clusterState = clusterService.state();
         if (clusterState.metadata().index(shardId.getIndex()).isSystem()) {
             return threadPool.executor(executorSelector.executorForGet(shardId.getIndexName()));
-        } else if (indicesService.indexServiceSafe(shardId.getIndex()).getIndexSettings().isSearchThrottled()) {
-            return threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED);
         } else {
             return super.getExecutor(request, shardId);
         }
diff --git a/server/src/main/java/org/elasticsearch/action/termvectors/TransportShardMultiTermsVectorAction.java b/server/src/main/java/org/elasticsearch/action/termvectors/TransportShardMultiTermsVectorAction.java
@@ -27,8 +27,6 @@
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 
-import java.util.concurrent.Executor;
-
 import static org.elasticsearch.core.Strings.format;
 
 public class TransportShardMultiTermsVectorAction extends TransportSingleShardAction<
@@ -109,12 +107,4 @@ protected MultiTermVectorsShardResponse shardOperation(MultiTermVectorsShardRequ
 
         return response;
     }
-
-    @Override
-    protected Executor getExecutor(MultiTermVectorsShardRequest request, ShardId shardId) {
-        IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
-        return indexService.getIndexSettings().isSearchThrottled()
-            ? threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED)
-            : super.getExecutor(request, shardId);
-    }
 }
diff --git a/server/src/main/java/org/elasticsearch/action/termvectors/TransportTermVectorsAction.java b/server/src/main/java/org/elasticsearch/action/termvectors/TransportTermVectorsAction.java
@@ -28,7 +28,6 @@
 import org.elasticsearch.transport.TransportService;
 
 import java.io.IOException;
-import java.util.concurrent.Executor;
 
 /**
  * Performs the get operation.
@@ -125,12 +124,4 @@ protected TermVectorsResponse shardOperation(TermVectorsRequest request, ShardId
     protected Writeable.Reader<TermVectorsResponse> getResponseReader() {
         return TermVectorsResponse::new;
     }
-
-    @Override
-    protected Executor getExecutor(TermVectorsRequest request, ShardId shardId) {
-        IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
-        return indexService.getIndexSettings().isSearchThrottled()
-            ? threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED)
-            : super.getExecutor(request, shardId);
-    }
 }
diff --git a/server/src/main/java/org/elasticsearch/common/settings/IndexScopedSettings.java b/server/src/main/java/org/elasticsearch/common/settings/IndexScopedSettings.java
@@ -150,7 +150,6 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
         IndexSettings.INDEX_TRANSLOG_RETENTION_AGE_SETTING,
         IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING,
         IndexSettings.INDEX_SEARCH_IDLE_AFTER,
-        IndexSettings.INDEX_SEARCH_THROTTLED,
         IndexFieldDataService.INDEX_FIELDDATA_CACHE_KEY,
         IndexSettings.IGNORE_ABOVE_SETTING,
         FieldMapper.IGNORE_MALFORMED_SETTING,
diff --git a/server/src/main/java/org/elasticsearch/index/IndexSettings.java b/server/src/main/java/org/elasticsearch/index/IndexSettings.java
@@ -536,17 +536,6 @@ public Iterator<Setting<?>> settings() {
         Property.ServerlessPublic
     );
 
-    /**
-     * Marks an index to be searched throttled. This means that never more than one shard of such an index will be searched concurrently
-     */
-    public static final Setting<Boolean> INDEX_SEARCH_THROTTLED = Setting.boolSetting(
-        "index.search.throttled",
-        false,
-        Property.IndexScope,
-        Property.PrivateIndex,
-        Property.Dynamic
-    );
-
     /**
      * Determines a balance between file-based and operations-based peer recoveries. The number of operations that will be used in an
      * operations-based peer recovery is limited to this proportion of the total number of documents in the shard (including deleted
@@ -891,7 +880,6 @@ private void setRetentionLeaseMillis(final TimeValue retentionLease) {
     private volatile int maxTermsCount;
     private volatile String defaultPipeline;
     private volatile String requiredPipeline;
-    private volatile boolean searchThrottled;
     private volatile long mappingNestedFieldsLimit;
     private volatile long mappingNestedDocsLimit;
     private volatile long mappingTotalFieldsLimit;
@@ -1019,7 +1007,6 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
                 this.timestampBounds = TimestampBounds.updateEndTime(this.timestampBounds, endTime);
             });
         }
-        this.searchThrottled = INDEX_SEARCH_THROTTLED.get(settings);
         this.queryStringLenient = QUERY_STRING_LENIENT_SETTING.get(settings);
         this.queryStringAnalyzeWildcard = QUERY_STRING_ANALYZE_WILDCARD.get(nodeSettings);
         this.queryStringAllowLeadingWildcard = QUERY_STRING_ALLOW_LEADING_WILDCARD.get(nodeSettings);
@@ -1175,7 +1162,6 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         scopedSettings.addSettingsUpdateConsumer(DEFAULT_PIPELINE, this::setDefaultPipeline);
         scopedSettings.addSettingsUpdateConsumer(FINAL_PIPELINE, this::setRequiredPipeline);
         scopedSettings.addSettingsUpdateConsumer(INDEX_SOFT_DELETES_RETENTION_OPERATIONS_SETTING, this::setSoftDeleteRetentionOperations);
-        scopedSettings.addSettingsUpdateConsumer(INDEX_SEARCH_THROTTLED, this::setSearchThrottled);
         scopedSettings.addSettingsUpdateConsumer(INDEX_SOFT_DELETES_RETENTION_LEASE_PERIOD_SETTING, this::setRetentionLeaseMillis);
         scopedSettings.addSettingsUpdateConsumer(INDEX_MAPPING_NESTED_FIELDS_LIMIT_SETTING, this::setMappingNestedFieldsLimit);
         scopedSettings.addSettingsUpdateConsumer(INDEX_MAPPING_NESTED_DOCS_LIMIT_SETTING, this::setMappingNestedDocsLimit);
@@ -1700,18 +1686,6 @@ public long getSoftDeleteRetentionOperations() {
         return this.softDeleteRetentionOperations;
     }
 
-    /**
-     * Returns true if the this index should be searched throttled ie. using the
-     * {@link org.elasticsearch.threadpool.ThreadPool.Names#SEARCH_THROTTLED} thread-pool
-     */
-    public boolean isSearchThrottled() {
-        return searchThrottled;
-    }
-
-    private void setSearchThrottled(boolean searchThrottled) {
-        this.searchThrottled = searchThrottled;
-    }
-
     public long getMappingNestedFieldsLimit() {
         return mappingNestedFieldsLimit;
     }
diff --git a/server/src/main/java/org/elasticsearch/node/NodeConstruction.java b/server/src/main/java/org/elasticsearch/node/NodeConstruction.java
@@ -566,6 +566,14 @@ private static void addBwcSearchWorkerSettings(List<Setting<?>> additionalSettin
         additionalSettings.add(
             Setting.intSetting("thread_pool.search_worker.size", 0, Setting.Property.NodeScope, Setting.Property.DeprecatedWarning)
         );
+        // Search throttled thread pool has been removed in Elasticsearch 9.0.0. These settings are deprecated and take no effect.
+        // They are here only to enable BwC for deployments that still use them
+        additionalSettings.add(
+            Setting.intSetting("thread_pool.search_throttled.queue_size", 0, Setting.Property.NodeScope, Setting.Property.DeprecatedWarning)
+        );
+        additionalSettings.add(
+            Setting.intSetting("thread_pool.search_throttled.size", 0, Setting.Property.NodeScope, Setting.Property.DeprecatedWarning)
+        );
     }
 
     private SearchModule createSearchModule(Settings settings, ThreadPool threadPool, TelemetryProvider telemetryProvider) {
diff --git a/server/src/main/java/org/elasticsearch/rest/action/cat/RestIndicesAction.java b/server/src/main/java/org/elasticsearch/rest/action/cat/RestIndicesAction.java
@@ -28,7 +28,6 @@
 import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.core.TimeValue;
-import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.RestResponse;
 import org.elasticsearch.rest.Scope;
@@ -117,7 +116,6 @@ public RestResponse buildResponse(Void ignored) throws Exception {
                     .prepareGetSettings(indices)
                     .setIndicesOptions(indicesOptions)
                     .setMasterNodeTimeout(masterNodeTimeout)
-                    .setNames(IndexSettings.INDEX_SEARCH_THROTTLED.getKey())
                     .execute(listeners.acquire(indexSettingsRef::set));
 
                 // The other requests just provide additional detail, and wildcards may be resolved differently depending on the type of
@@ -480,8 +478,6 @@ protected Table getTableWithHeader(final RestRequest request) {
         table.addCell("memory.total", "sibling:pri;alias:tm,memoryTotal;default:false;text-align:right;desc:total used memory");
         table.addCell("pri.memory.total", "default:false;text-align:right;desc:total user memory");
 
-        table.addCell("search.throttled", "alias:sth;default:false;desc:indicates if the index is search throttled");
-
         table.addCell(
             "bulk.total_operations",
             "sibling:pri;alias:bto,bulkTotalOperation;default:false;text-align:right;desc:number of bulk shard ops"
@@ -553,7 +549,6 @@ Table buildTable(
 
             final IndexMetadata.State indexState = indexMetadata.getState();
             final IndexStats indexStats = indicesStats.get(indexName);
-            final boolean searchThrottled = IndexSettings.INDEX_SEARCH_THROTTLED.get(settings);
 
             final IndexRoutingTable indexRoutingTable = clusterState.routingTable().index(indexName);
             final ClusterHealthStatus indexHealthStatus = indexRoutingTable == null
@@ -788,8 +783,6 @@ Table buildTable(
             table.addCell(totalStats.getTotalMemory());
             table.addCell(primaryStats.getTotalMemory());
 
-            table.addCell(searchThrottled);
-
             table.addCell(totalStats.getBulk() == null ? null : totalStats.getBulk().getTotalOperations());
             table.addCell(primaryStats.getBulk() == null ? null : primaryStats.getBulk().getTotalOperations());
 
diff --git a/server/src/main/java/org/elasticsearch/search/SearchService.java b/server/src/main/java/org/elasticsearch/search/SearchService.java
@@ -908,8 +908,6 @@ private Executor getExecutor(IndexShard indexShard) {
         final String executorName;
         if (indexShard.isSystem()) {
             executorName = executorSelector.executorForSearch(indexShard.shardId().getIndexName());
-        } else if (indexShard.indexSettings().isSearchThrottled()) {
-            executorName = Names.SEARCH_THROTTLED;
         } else {
             executorName = Names.SEARCH;
         }
diff --git a/server/src/main/java/org/elasticsearch/threadpool/DefaultBuiltInExecutorBuilders.java b/server/src/main/java/org/elasticsearch/threadpool/DefaultBuiltInExecutorBuilders.java
@@ -92,10 +92,6 @@ public Map<String, ExecutorBuilder> getBuilders(Settings settings, int allocated
                 EsExecutors.TaskTrackingConfig.DEFAULT
             )
         );
-        result.put(
-            ThreadPool.Names.SEARCH_THROTTLED,
-            new FixedExecutorBuilder(settings, ThreadPool.Names.SEARCH_THROTTLED, 1, 100, EsExecutors.TaskTrackingConfig.DEFAULT)
-        );
         result.put(
             ThreadPool.Names.MANAGEMENT,
             new ScalingExecutorBuilder(
diff --git a/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java b/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
@@ -115,8 +115,6 @@ public static class Names {
         public static final String SEARCH = "search";
         public static final String SEARCH_COORDINATION = "search_coordination";
         public static final String AUTO_COMPLETE = "auto_complete";
-        public static final String SEARCH_THROTTLED = "search_throttled";
-
         /**
          * A thread pool for running tasks related to cluster management, including collecting and exposing stats in APIs and certain other
          * internal tasks.
@@ -197,7 +195,6 @@ public static ThreadPoolType fromType(String type) {
         entry(Names.FORCE_MERGE, ThreadPoolType.FIXED),
         entry(Names.FETCH_SHARD_STARTED, ThreadPoolType.SCALING),
         entry(Names.FETCH_SHARD_STORE, ThreadPoolType.SCALING),
-        entry(Names.SEARCH_THROTTLED, ThreadPoolType.FIXED),
         entry(Names.SYSTEM_READ, ThreadPoolType.FIXED),
         entry(Names.SYSTEM_WRITE, ThreadPoolType.FIXED),
         entry(Names.SYSTEM_CRITICAL_READ, ThreadPoolType.FIXED),
diff --git a/server/src/test/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolverTests.java b/server/src/test/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolverTests.java
@@ -30,7 +30,6 @@
 import org.elasticsearch.core.Tuple;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexNotFoundException;
-import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.indices.IndexClosedException;
 import org.elasticsearch.indices.InvalidIndexNameException;
@@ -2269,7 +2268,7 @@ public void testIgnoreThrottled() {
                     .putAlias(AliasMetadata.builder("test-alias"))
             )
             .put(
-                indexBuilder("index", Settings.builder().put(IndexSettings.INDEX_SEARCH_THROTTLED.getKey(), true).build()).state(State.OPEN)
+                indexBuilder("index", Settings.builder().put("index.search.throttled", true).build()).state(State.OPEN)
                     .putAlias(AliasMetadata.builder("test-alias2"))
             )
             .put(
diff --git a/server/src/test/java/org/elasticsearch/rest/action/cat/RestIndicesActionTests.java b/server/src/test/java/org/elasticsearch/rest/action/cat/RestIndicesActionTests.java
@@ -25,7 +25,6 @@
 import org.elasticsearch.common.UUIDs;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.Index;
-import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.test.ESTestCase;
@@ -58,7 +57,6 @@ public void testBuildTable() {
             Settings indexSettings = Settings.builder()
                 .put(IndexMetadata.SETTING_VERSION_CREATED, IndexVersion.current())
                 .put(IndexMetadata.SETTING_INDEX_UUID, UUIDs.randomBase64UUID())
-                .put(IndexSettings.INDEX_SEARCH_THROTTLED.getKey(), randomBoolean())
                 .build();
             indicesSettings.put(indexName, indexSettings);
 
diff --git a/server/src/test/java/org/elasticsearch/search/SearchServiceSingleNodeTests.java b/server/src/test/java/org/elasticsearch/search/SearchServiceSingleNodeTests.java
@@ -58,7 +58,6 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.AbstractRefCounted;
 import org.elasticsearch.core.TimeValue;
-import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexModule;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.IndexService;
@@ -167,7 +166,6 @@
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertResponse;
-import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertSearchHits;
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -1846,46 +1844,6 @@ public void testCanRewriteToMatchNone() {
         );
     }
 
-    public void testSetSearchThrottled() throws IOException {
-        createIndex("throttled_threadpool_index");
-        client().execute(
-            InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.INSTANCE,
-            new InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.Request(
-                "throttled_threadpool_index",
-                IndexSettings.INDEX_SEARCH_THROTTLED.getKey(),
-                "true"
-            )
-        ).actionGet();
-        final SearchService service = getInstanceFromNode(SearchService.class);
-        Index index = resolveIndex("throttled_threadpool_index");
-        assertTrue(service.getIndicesService().indexServiceSafe(index).getIndexSettings().isSearchThrottled());
-        prepareIndex("throttled_threadpool_index").setId("1").setSource("field", "value").setRefreshPolicy(IMMEDIATE).get();
-        assertSearchHits(
-            client().prepareSearch("throttled_threadpool_index")
-                .setIndicesOptions(IndicesOptions.STRICT_EXPAND_OPEN_FORBID_CLOSED)
-                .setSize(1),
-            "1"
-        );
-        // we add a search action listener in a plugin above to assert that this is actually used
-        client().execute(
-            InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.INSTANCE,
-            new InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.Request(
-                "throttled_threadpool_index",
-                IndexSettings.INDEX_SEARCH_THROTTLED.getKey(),
-                "false"
-            )
-        ).actionGet();
-
-        IllegalArgumentException iae = expectThrows(
-            IllegalArgumentException.class,
-            () -> indicesAdmin().prepareUpdateSettings("throttled_threadpool_index")
-                .setSettings(Settings.builder().put(IndexSettings.INDEX_SEARCH_THROTTLED.getKey(), false))
-                .get()
-        );
-        assertEquals("can not update private setting [index.search.throttled]; this setting is managed by Elasticsearch", iae.getMessage());
-        assertFalse(service.getIndicesService().indexServiceSafe(index).getIndexSettings().isSearchThrottled());
-    }
-
     public void testAggContextGetsMatchAll() throws IOException {
         createIndex("test");
         withAggregationContext("test", context -> assertThat(context.query(), equalTo(new MatchAllDocsQuery())));
@@ -1937,22 +1895,6 @@ private void withAggregationContext(String index, Consumer<AggregationContext> c
         }
     }
 
-    public void testExpandSearchThrottled() {
-        createIndex("throttled_threadpool_index");
-        client().execute(
-            InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.INSTANCE,
-            new InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.Request(
-                "throttled_threadpool_index",
-                IndexSettings.INDEX_SEARCH_THROTTLED.getKey(),
-                "true"
-            )
-        ).actionGet();
-
-        prepareIndex("throttled_threadpool_index").setId("1").setSource("field", "value").setRefreshPolicy(IMMEDIATE).get();
-        assertHitCount(client().prepareSearch(), 1L);
-        assertHitCount(client().prepareSearch().setIndicesOptions(IndicesOptions.STRICT_EXPAND_OPEN_FORBID_CLOSED), 1L);
-    }
-
     public void testExpandSearchFrozen() {
         String indexName = "frozen_index";
         createIndex(indexName);
diff --git a/x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportResumeFollowAction.java b/x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportResumeFollowAction.java
@@ -485,7 +485,6 @@ static String[] extractLeaderShardHistoryUUIDs(Map<String, String> ccrIndexMetad
         IndexSettings.MAX_SLICES_PER_SCROLL,
         IndexSettings.DEFAULT_PIPELINE,
         IndexSettings.FINAL_PIPELINE,
-        IndexSettings.INDEX_SEARCH_THROTTLED,
         IndexSettings.INDEX_TRANSLOG_RETENTION_AGE_SETTING,
         IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING,
         IndexSettings.INDEX_TRANSLOG_GENERATION_THRESHOLD_SIZE_SETTING,
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/input/MetadataCachingIndexInput.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/input/MetadataCachingIndexInput.java

Original file line number	Diff line number	Diff line change
`@@ -108,4 +108,5 @@ tasks.named("yamlRestCompatTestTransform").configure ({ task ->`
`108`	`108`	`"cluster.desired_nodes/10_basic/Test update desired nodes with node_version generates a warning",`
`109`	`109`	`"node_version warning is removed in 9.0"`
`110`	`110`	`)`
	`111`	`+ task.skipTest("cluster.info/30_info_thread_pool/Cluster HTTP Info", "The search_throttled thread pool has been removed")`
`111`	`112`	`})`
Original file line number	Diff line number	Diff line change
`@@ -166,8 +166,6 @@ protected Executor getExecutor(GetRequest request, ShardId shardId) {`
`166`	`166`	`final ClusterState clusterState = clusterService.state();`
`167`	`167`	`if (clusterState.metadata().getIndexSafe(shardId.getIndex()).isSystem()) {`
`168`	`168`	`return threadPool.executor(executorSelector.executorForGet(shardId.getIndexName()));`
`169`		`- } else if (indicesService.indexServiceSafe(shardId.getIndex()).getIndexSettings().isSearchThrottled()) {`
`170`		`- return threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED);`
`171`	`169`	`} else {`
`172`	`170`	`return super.getExecutor(request, shardId);`
`173`	`171`	`}`
Original file line number	Diff line number	Diff line change
`@@ -155,8 +155,6 @@ protected Executor getExecutor(MultiGetShardRequest request, ShardId shardId) {`
`155`	`155`	`final ClusterState clusterState = clusterService.state();`
`156`	`156`	`if (clusterState.metadata().index(shardId.getIndex()).isSystem()) {`
`157`	`157`	`return threadPool.executor(executorSelector.executorForGet(shardId.getIndexName()));`
`158`		`- } else if (indicesService.indexServiceSafe(shardId.getIndex()).getIndexSettings().isSearchThrottled()) {`
`159`		`- return threadPool.executor(ThreadPool.Names.SEARCH_THROTTLED);`
`160`	`158`	`} else {`
`161`	`159`	`return super.getExecutor(request, shardId);`
`162`	`160`	`}`