Fix stuff after cherry-picking

test/framework/src/main/java/org/elasticsearch/common/lucene/store/ESIndexInputTestCase.java

@@ -43,7 +43,7 @@ public class ESIndexInputTestCase extends ESTestCase {
     @BeforeClass
     public static void createExecutor() {
         final String name = "TEST-" + getTestClass().getSimpleName() + "#randomReadAndSlice";
-        executor = EsExecutors.newFixed(name, 10, 0, EsExecutors.daemonThreadFactory(name), new ThreadContext(Settings.EMPTY), false);
+        executor = EsExecutors.newFixed(name, 10, 0, EsExecutors.daemonThreadFactory(name), new ThreadContext(Settings.EMPTY));
     }
 
     @AfterClass

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/CleanupSnapshotStep.java

@@ -50,7 +50,7 @@ public class CleanupSnapshotStep extends AsyncRetryDuringSnapshotActionStep {
             return;
         }
         DeleteSnapshotRequest deleteSnapshotRequest = new DeleteSnapshotRequest(repositoryName, snapshotName);
-        getClient().admin().cluster().deleteSnapshot(deleteSnapshotRequest, new ActionListener<>() {
+        getClient().admin().cluster().deleteSnapshot(deleteSnapshotRequest, new ActionListener<AcknowledgedResponse>() {
 
             @Override
             public void onResponse(AcknowledgedResponse acknowledgedResponse) {

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/DeleteAction.java

@@ -50,7 +50,7 @@ public class DeleteAction implements LifecycleAction {
     }
 
     public DeleteAction(StreamInput in) throws IOException {
-        if (in.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_7_8_0)) {
             this.deleteSearchableSnapshot = in.readBoolean();
         } else {
             this.deleteSearchableSnapshot = true;
@@ -59,7 +59,7 @@ public class DeleteAction implements LifecycleAction {
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_7_8_0)) {
             out.writeBoolean(deleteSearchableSnapshot);
         }
     }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/IndexLifecycleExplainResponse.java

@@ -194,7 +194,7 @@ public class IndexLifecycleExplainResponse implements ToXContentObject, Writeabl
                 isAutoRetryableError = null;
                 failedStepRetryCount = null;
             }
-            if (in.getVersion().onOrAfter(Version.V_8_0_0)) {
+            if (in.getVersion().onOrAfter(Version.V_7_8_0)) {
                repositoryName = in.readOptionalString();
                snapshotName = in.readOptionalString();
             } else {
@@ -240,7 +240,7 @@ public class IndexLifecycleExplainResponse implements ToXContentObject, Writeabl
                 out.writeOptionalBoolean(isAutoRetryableError);
                 out.writeOptionalVInt(failedStepRetryCount);
             }
-            if (out.getVersion().onOrAfter(Version.V_8_0_0)) {
+            if (out.getVersion().onOrAfter(Version.V_7_8_0)) {
                 out.writeOptionalString(repositoryName);
                 out.writeOptionalString(snapshotName);
             }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/searchablesnapshots/MountSearchableSnapshotRequest.java

@@ -33,12 +33,12 @@ public class MountSearchableSnapshotRequest extends MasterNodeRequest<MountSearc
     public static final ConstructingObjectParser<MountSearchableSnapshotRequest, RestRequest> PARSER = new ConstructingObjectParser<>(
         "mount_searchable_snapshot", true,
         (a, request) -> new MountSearchableSnapshotRequest(
-            Objects.requireNonNullElse((String)a[1], (String)a[0]),
+            (String) ((a[1] != null) ? a[1] : Objects.requireNonNull(a[0])),
             request.param("repository"),
             request.param("snapshot"),
-            (String)a[0],
+            (String) a[0],
-            Objects.requireNonNullElse((Settings)a[2], Settings.EMPTY),
+            (Settings) ((a[2] != null) ? a[2] : Settings.EMPTY),
-            Objects.requireNonNullElse((String[])a[3], Strings.EMPTY_ARRAY),
+            (String[]) ((a[3] != null) ? a[3] : Strings.EMPTY_ARRAY),
             request.paramAsBoolean("wait_for_completion", false)));
 
     private static final ParseField INDEX_FIELD = new ParseField("index");

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/CleanupSnapshotStepTests.java

@@ -88,7 +88,7 @@ public class CleanupSnapshotStepTests extends AbstractStepTestCase<CleanupSnapsh
             IndexMetadata.Builder indexMetadataBuilder =
                 IndexMetadata.builder(indexName).settings(settings(Version.CURRENT).put(LifecycleSettings.LIFECYCLE_NAME, policyName))
                     .numberOfShards(randomIntBetween(1, 5)).numberOfReplicas(randomIntBetween(0, 5));
-            Map<String, String> ilmCustom = Map.of("snapshot_repository", "repository_name");
+            Map<String, String> ilmCustom = org.elasticsearch.common.collect.Map.of("snapshot_repository", "repository_name");
             indexMetadataBuilder.putCustom(LifecycleExecutionState.ILM_CUSTOM_METADATA_KEY, ilmCustom);
 
             IndexMetadata indexMetaData = indexMetadataBuilder.build();
@@ -116,7 +116,7 @@ public class CleanupSnapshotStepTests extends AbstractStepTestCase<CleanupSnapsh
         String indexName = randomAlphaOfLength(10);
         String policyName = "test-ilm-policy";
         String snapshotName = indexName + "-" + policyName;
-        Map<String, String> ilmCustom = Map.of("snapshot_name", snapshotName);
+        Map<String, String> ilmCustom = org.elasticsearch.common.collect.Map.of("snapshot_name", snapshotName);
 
         IndexMetadata.Builder indexMetadataBuilder =
             IndexMetadata.builder(indexName).settings(settings(Version.CURRENT).put(LifecycleSettings.LIFECYCLE_NAME, policyName))

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/MountSnapshotStepTests.java

@@ -21,9 +21,9 @@ import org.elasticsearch.xpack.core.searchablesnapshots.MountSearchableSnapshotA
 import org.elasticsearch.xpack.core.searchablesnapshots.MountSearchableSnapshotRequest;
 
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
+import static java.util.Collections.emptyList;
 import static org.elasticsearch.xpack.core.ilm.AbstractStepMasterTimeoutTestCase.emptyClusterState;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.is;
@@ -179,7 +179,7 @@ public class MountSnapshotStepTests extends AbstractStepTestCase<MountSnapshotSt
             ClusterState.builder(emptyClusterState()).metadata(Metadata.builder().put(indexMetaData, true).build()).build();
 
         {
-            RestoreSnapshotResponse responseWithOKStatus = new RestoreSnapshotResponse(new RestoreInfo("test", List.of(), 1, 1));
+            RestoreSnapshotResponse responseWithOKStatus = new RestoreSnapshotResponse(new RestoreInfo("test", emptyList(), 1, 1));
             try (NoOpClient clientPropagatingOKResponse = getClientTriggeringResponse(responseWithOKStatus)) {
                 MountSnapshotStep step = new MountSnapshotStep(randomStepKey(), randomStepKey(), clientPropagatingOKResponse,
                     RESTORED_INDEX_PREFIX);

x-pack/plugin/ilm/qa/multi-node/src/test/java/org/elasticsearch/xpack/ilm/TimeSeriesLifecycleActionsIT.java

@@ -1593,7 +1593,7 @@ public class TimeSeriesLifecycleActionsIT extends ESRestTestCase {
 
         // create policy with cold and delete phases
         Map<String, LifecycleAction> coldActions =
-            Map.of(SearchableSnapshotAction.NAME, new SearchableSnapshotAction(snapshotRepo));
+            singletonMap(SearchableSnapshotAction.NAME, new SearchableSnapshotAction(snapshotRepo));
         Map<String, Phase> phases = new HashMap<>();
         phases.put("cold", new Phase("cold", TimeValue.ZERO, coldActions));
         phases.put("delete", new Phase("delete", TimeValue.timeValueMillis(10000), singletonMap(DeleteAction.NAME,
@@ -1649,7 +1649,7 @@ public class TimeSeriesLifecycleActionsIT extends ESRestTestCase {
 
         // create policy with cold and delete phases
         Map<String, LifecycleAction> coldActions =
-            Map.of(SearchableSnapshotAction.NAME, new SearchableSnapshotAction(snapshotRepo));
+            singletonMap(SearchableSnapshotAction.NAME, new SearchableSnapshotAction(snapshotRepo));
         Map<String, Phase> phases = new HashMap<>();
         phases.put("cold", new Phase("cold", TimeValue.ZERO, coldActions));
         phases.put("delete", new Phase("delete", TimeValue.timeValueMillis(10000), singletonMap(DeleteAction.NAME,

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/index/store/SearchableSnapshotDirectory.java

@@ -174,7 +174,7 @@ public class SearchableSnapshotDirectory extends BaseDirectory {
 
     private List<BlobStoreIndexShardSnapshot.FileInfo> files() {
         if (loaded == false) {
-            return List.of();
+            return Collections.emptyList();
         }
         final List<BlobStoreIndexShardSnapshot.FileInfo> files = snapshot().indexFiles();
         assert files != null;

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java

@@ -66,6 +66,12 @@ import java.util.Optional;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.singletonList;
+import static java.util.Collections.singletonMap;
+import static java.util.Collections.unmodifiableList;
 import static org.elasticsearch.index.IndexModule.INDEX_STORE_TYPE_SETTING;
 
 /**
@@ -118,7 +124,7 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
     // The file extensions that are excluded from the cache
     public static final Setting<List<String>> SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING = Setting.listSetting(
         "index.store.snapshot.cache.excluded_file_types",
-        Collections.emptyList(),
+        emptyList(),
         Function.identity(),
         Setting.Property.IndexScope,
         Setting.Property.NodeScope
@@ -151,19 +157,21 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
     @Override
     public List<Setting<?>> getSettings() {
         if (SEARCHABLE_SNAPSHOTS_FEATURE_ENABLED) {
-            return List.of(
+            return unmodifiableList(
-                SNAPSHOT_REPOSITORY_SETTING,
+                asList(
-                SNAPSHOT_SNAPSHOT_NAME_SETTING,
+                    SNAPSHOT_REPOSITORY_SETTING,
-                SNAPSHOT_SNAPSHOT_ID_SETTING,
+                    SNAPSHOT_SNAPSHOT_NAME_SETTING,
-                SNAPSHOT_INDEX_ID_SETTING,
+                    SNAPSHOT_SNAPSHOT_ID_SETTING,
-                SNAPSHOT_CACHE_ENABLED_SETTING,
+                    SNAPSHOT_INDEX_ID_SETTING,
-                SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING,
+                    SNAPSHOT_CACHE_ENABLED_SETTING,
-                SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING,
+                    SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING,
-                CacheService.SNAPSHOT_CACHE_SIZE_SETTING,
+                    SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING,
-                CacheService.SNAPSHOT_CACHE_RANGE_SIZE_SETTING
+                    CacheService.SNAPSHOT_CACHE_SIZE_SETTING,
+                    CacheService.SNAPSHOT_CACHE_RANGE_SIZE_SETTING
+                )
             );
         } else {
-            return List.of();
+            return emptyList();
         }
     }
 
@@ -183,9 +191,9 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
         if (SEARCHABLE_SNAPSHOTS_FEATURE_ENABLED) {
             final CacheService cacheService = new CacheService(settings);
             this.cacheService.set(cacheService);
-            return List.of(cacheService);
+            return singletonList(cacheService);
         } else {
-            return List.of();
+            return emptyList();
         }
     }
 
@@ -205,7 +213,7 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
     @Override
     public Map<String, DirectoryFactory> getDirectoryFactories() {
         if (SEARCHABLE_SNAPSHOTS_FEATURE_ENABLED) {
-            return Map.of(SNAPSHOT_DIRECTORY_FACTORY_KEY, (indexSettings, shardPath) -> {
+            return singletonMap(SNAPSHOT_DIRECTORY_FACTORY_KEY, (indexSettings, shardPath) -> {
                 final RepositoriesService repositories = repositoriesService.get();
                 assert repositories != null;
                 final CacheService cache = cacheService.get();
@@ -213,7 +221,7 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
                 return SearchableSnapshotDirectory.create(repositories, cache, indexSettings, shardPath, System::nanoTime);
             });
         } else {
-            return Map.of();
+            return emptyMap();
         }
     }
 
@@ -230,13 +238,13 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
     @Override
     public List<ActionHandler<? extends ActionRequest, ? extends ActionResponse>> getActions() {
         if (SEARCHABLE_SNAPSHOTS_FEATURE_ENABLED) {
-            return List.of(
+            return org.elasticsearch.common.collect.List.of(
                 new ActionHandler<>(SearchableSnapshotsStatsAction.INSTANCE, TransportSearchableSnapshotsStatsAction.class),
                 new ActionHandler<>(ClearSearchableSnapshotsCacheAction.INSTANCE, TransportClearSearchableSnapshotsCacheAction.class),
                 new ActionHandler<>(MountSearchableSnapshotAction.INSTANCE, TransportMountSearchableSnapshotAction.class)
             );
         } else {
-            return List.of();
+            return emptyList();
         }
     }
 
@@ -250,13 +258,15 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
         Supplier<DiscoveryNodes> nodesInCluster
     ) {
         if (SEARCHABLE_SNAPSHOTS_FEATURE_ENABLED) {
-            return List.of(
+            return unmodifiableList(
-                new RestSearchableSnapshotsStatsAction(),
+                asList(
-                new RestClearSearchableSnapshotsCacheAction(),
+                    new RestSearchableSnapshotsStatsAction(),
-                new RestMountSearchableSnapshotAction()
+                    new RestClearSearchableSnapshotsCacheAction(),
+                    new RestMountSearchableSnapshotAction()
+                )
             );
         } else {
-            return List.of();
+            return emptyList();
         }
     }
 

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/action/TransportMountSearchableSnapshotAction.java

@@ -30,7 +30,6 @@ import org.elasticsearch.repositories.RepositoriesService;
 import org.elasticsearch.repositories.Repository;
 import org.elasticsearch.repositories.RepositoryData;
 import org.elasticsearch.snapshots.SnapshotId;
-import org.elasticsearch.tasks.Task;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 import org.elasticsearch.xpack.core.searchablesnapshots.MountSearchableSnapshotAction;
@@ -121,7 +120,6 @@ public class TransportMountSearchableSnapshotAction extends TransportMasterNodeA
 
     @Override
     protected void masterOperation(
-        Task task,
         final MountSearchableSnapshotRequest request,
         final ClusterState state,
         final ActionListener<RestoreSnapshotResponse> listener
@@ -148,7 +146,7 @@ public class TransportMountSearchableSnapshotAction extends TransportMasterNodeA
                 .stream()
                 .filter(s -> snapName.equals(s.getName()))
                 .findFirst();
-            if (matchingSnapshotId.isEmpty()) {
+            if (matchingSnapshotId.isPresent() == false) {
                 throw new ElasticsearchException("snapshot [" + snapName + "] not found in repository [" + repoName + "]");
             }
             final SnapshotId snapshotId = matchingSnapshotId.get();

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/rest/RestClearSearchableSnapshotsCacheAction.java

@@ -16,13 +16,18 @@ import org.elasticsearch.xpack.searchablesnapshots.action.ClearSearchableSnapsho
 
 import java.util.List;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.unmodifiableList;
+
 public class RestClearSearchableSnapshotsCacheAction extends BaseRestHandler {
 
     @Override
     public List<Route> routes() {
-        return List.of(
+        return unmodifiableList(
-            new Route(RestRequest.Method.POST, "/_searchable_snapshots/cache/clear"),
+            asList(
-            new Route(RestRequest.Method.POST, "/{index}/_searchable_snapshots/cache/clear")
+                new Route(RestRequest.Method.POST, "/_searchable_snapshots/cache/clear"),
+                new Route(RestRequest.Method.POST, "/{index}/_searchable_snapshots/cache/clear")
+            )
         );
     }
 

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/rest/RestSearchableSnapshotsStatsAction.java

@@ -15,13 +15,18 @@ import org.elasticsearch.xpack.searchablesnapshots.action.SearchableSnapshotsSta
 
 import java.util.List;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.unmodifiableList;
+
 public class RestSearchableSnapshotsStatsAction extends BaseRestHandler {
 
     @Override
     public List<Route> routes() {
-        return List.of(
+        return unmodifiableList(
-            new Route(RestRequest.Method.GET, "/_searchable_snapshots/stats"),
+            asList(
-            new Route(RestRequest.Method.GET, "/{index}/_searchable_snapshots/stats")
+                new Route(RestRequest.Method.GET, "/_searchable_snapshots/stats"),
+                new Route(RestRequest.Method.GET, "/{index}/_searchable_snapshots/stats")
+            )
         );
     }
 

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryStatsTests.java

@@ -26,6 +26,7 @@ import org.elasticsearch.xpack.searchablesnapshots.cache.CacheService;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.LongSupplier;
@@ -566,7 +567,7 @@ public class SearchableSnapshotDirectoryStatsTests extends ESIndexInputTestCase
         final String blobName = randomUnicodeOfLength(10);
         final BlobContainer blobContainer = singleBlobContainer(blobName, fileContent);
         final StoreFileMetadata metadata = new StoreFileMetadata(fileName, fileContent.length, "_checksum", Version.CURRENT.luceneVersion);
-        final List<FileInfo> files = List.of(new FileInfo(blobName, metadata, new ByteSizeValue(fileContent.length)));
+        final List<FileInfo> files = Collections.singletonList(new FileInfo(blobName, metadata, new ByteSizeValue(fileContent.length)));
         final BlobStoreIndexShardSnapshot snapshot = new BlobStoreIndexShardSnapshot(snapshotId.getName(), 0L, files, 0L, 0L, 0, 0L);
 
         try (

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryTests.java

@@ -90,6 +90,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import static java.util.Arrays.asList;
 import static java.util.Collections.emptyMap;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_CACHE_ENABLED_SETTING;
 import static org.hamcrest.Matchers.allOf;
@@ -153,7 +154,7 @@ public class SearchableSnapshotDirectoryTests extends ESTestCase {
                         CheckHits.checkEqual(query, snapshotSearcher.search(query, 10).scoreDocs, searcher.search(query, 10).scoreDocs);
                     }
                     {
-                        Query query = new TermInSetQuery("text", List.of(new BytesRef("quick"), new BytesRef("lazy")));
+                        Query query = new TermInSetQuery("text", asList(new BytesRef("quick"), new BytesRef("lazy")));
                         assertThat(snapshotSearcher.count(query), equalTo(searcher.count(query)));
                         CheckHits.checkEqual(query, snapshotSearcher.search(query, 10).scoreDocs, searcher.search(query, 10).scoreDocs);
                     }
@@ -328,7 +329,7 @@ public class SearchableSnapshotDirectoryTests extends ESTestCase {
             final IndexWriterConfig indexWriterConfig = newIndexWriterConfig();
             try (IndexWriter writer = new IndexWriter(directory, indexWriterConfig)) {
                 final int nbDocs = scaledRandomIntBetween(0, 1_000);
-                final List<String> words = List.of("the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog");
+                final List<String> words = asList("the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog");
                 for (int i = 0; i < nbDocs; i++) {
                     final Document doc = new Document();
                     doc.add(new StringField("id", "" + i, Field.Store.YES));
@@ -460,7 +461,7 @@ public class SearchableSnapshotDirectoryTests extends ESTestCase {
 
     private void testIndexInputs(final CheckedBiConsumer<IndexInput, IndexInput, Exception> consumer) throws Exception {
         testDirectories((directory, snapshotDirectory) -> {
-            for (String fileName : randomSubsetOf(Arrays.asList(snapshotDirectory.listAll()))) {
+            for (String fileName : randomSubsetOf(asList(snapshotDirectory.listAll()))) {
                 final IOContext context = newIOContext(random());
                 try (IndexInput indexInput = directory.openInput(fileName, context)) {
                     final List<Closeable> closeables = new ArrayList<>();

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/cache/CachedBlobContainerIndexInputTests.java

@@ -27,10 +27,10 @@ import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.atomic.LongAdder;
 
+import static java.util.Collections.singletonList;
 import static org.elasticsearch.index.store.cache.TestUtils.createCacheService;
 import static org.elasticsearch.index.store.cache.TestUtils.singleBlobContainer;
 import static org.elasticsearch.index.store.cache.TestUtils.singleSplitBlobContainer;
@@ -61,7 +61,7 @@ public class CachedBlobContainerIndexInputTests extends ESIndexInputTestCase {
                 final BlobStoreIndexShardSnapshot snapshot = new BlobStoreIndexShardSnapshot(
                     snapshotId.getName(),
                     0L,
-                    List.of(new BlobStoreIndexShardSnapshot.FileInfo(blobName, metaData, new ByteSizeValue(partSize))),
+                    singletonList(new BlobStoreIndexShardSnapshot.FileInfo(blobName, metaData, new ByteSizeValue(partSize))),
                     0L,
                     0L,
                     0,
@@ -136,7 +136,7 @@ public class CachedBlobContainerIndexInputTests extends ESIndexInputTestCase {
             final BlobStoreIndexShardSnapshot snapshot = new BlobStoreIndexShardSnapshot(
                 snapshotId.getName(),
                 0L,
-                List.of(new BlobStoreIndexShardSnapshot.FileInfo(blobName, metadata, new ByteSizeValue(input.length + 1))),
+                singletonList(new BlobStoreIndexShardSnapshot.FileInfo(blobName, metadata, new ByteSizeValue(input.length + 1))),
                 0L,
                 0L,
                 0,

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/cache/SparseFileTrackerTests.java

@@ -195,7 +195,7 @@ public class SparseFileTrackerTests extends ESTestCase {
         final AtomicBoolean listenerCalled = new AtomicBoolean();
         listenerCalledConsumer.accept(listenerCalled);
 
-        final List<SparseFileTracker.Gap> gaps = sparseFileTracker.waitForRange(start, end, new ActionListener<>() {
+        final List<SparseFileTracker.Gap> gaps = sparseFileTracker.waitForRange(start, end, new ActionListener<Void>() {
             @Override
             public void onResponse(Void aVoid) {
                 for (long i = start; i < end; i++) {

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/cache/TestUtils.java

@@ -25,6 +25,7 @@ import java.util.Random;
 
 import static com.carrotsearch.randomizedtesting.generators.RandomNumbers.randomIntBetween;
 import static com.carrotsearch.randomizedtesting.generators.RandomPicks.randomFrom;
+import static java.util.Arrays.asList;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 
@@ -34,7 +35,7 @@ public final class TestUtils {
     public static CacheService createCacheService(final Random random) {
         final ByteSizeValue cacheSize = new ByteSizeValue(
             randomIntBetween(random, 1, 100),
-            randomFrom(random, List.of(ByteSizeUnit.BYTES, ByteSizeUnit.KB, ByteSizeUnit.MB, ByteSizeUnit.GB))
+            randomFrom(random, asList(ByteSizeUnit.BYTES, ByteSizeUnit.KB, ByteSizeUnit.MB, ByteSizeUnit.GB))
         );
         return new CacheService(cacheSize, randomCacheRangeSize(random));
     }
@@ -42,7 +43,7 @@ public final class TestUtils {
     public static ByteSizeValue randomCacheRangeSize(final Random random) {
         return new ByteSizeValue(
             randomIntBetween(random, 1, 100),
-            randomFrom(random, List.of(ByteSizeUnit.BYTES, ByteSizeUnit.KB, ByteSizeUnit.MB))
+            randomFrom(random, asList(ByteSizeUnit.BYTES, ByteSizeUnit.KB, ByteSizeUnit.MB))
         );
     }
 

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/xpack/searchablesnapshots/BaseSearchableSnapshotsIntegTestCase.java

@@ -34,7 +34,9 @@ import org.elasticsearch.xpack.core.LocalStateCompositeXPackPlugin;
 import org.elasticsearch.xpack.searchablesnapshots.cache.CacheService;
 
 import java.util.Collection;
-import java.util.List;
+
+import static java.util.Arrays.asList;
+import static java.util.Collections.unmodifiableList;
 
 public abstract class BaseSearchableSnapshotsIntegTestCase extends ESIntegTestCase {
     @Override
@@ -44,7 +46,7 @@ public abstract class BaseSearchableSnapshotsIntegTestCase extends ESIntegTestCa
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return List.of(SearchableSnapshots.class, LocalStateCompositeXPackPlugin.class);
+        return unmodifiableList(asList(SearchableSnapshots.class, LocalStateCompositeXPackPlugin.class));
     }
 
     @Override

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshotsIntegTests.java

@@ -69,7 +69,7 @@ public class SearchableSnapshotsIntegTests extends BaseSearchableSnapshotsIntegT
         createIndex(indexName);
         final List<IndexRequestBuilder> indexRequestBuilders = new ArrayList<>();
         for (int i = between(10, 10_000); i >= 0; i--) {
-            indexRequestBuilders.add(client().prepareIndex(indexName).setSource("foo", randomBoolean() ? "bar" : "baz"));
+            indexRequestBuilders.add(client().prepareIndex(indexName, "_doc").setSource("foo", randomBoolean() ? "bar" : "baz"));
         }
         // TODO NORELEASE no dummy docs since that includes deletes, yet we always copy the .liv file in peer recovery
         indexRandom(true, false, indexRequestBuilders);