From 6df6380e80e650c4e89db29c7c13e6ce6c8029f8 Mon Sep 17 00:00:00 2001
From: Rory Hunter <pugnascotia@users.noreply.github.com>
Date: Tue, 7 Dec 2021 13:51:47 +0000
Subject: [PATCH] Checkstyle shadows vars pt10 (#81361)

Backport of #81361.

Part of #19752. Fix more instances where local variable names were
shadowing field names.
---
 .../src/main/resources/checkstyle.xml         |  9 +++-
 .../xpack/ml/MachineLearning.java             | 10 ++--
 .../xpack/ml/MlInitializationService.java     |  4 +-
 .../TransportDeleteExpiredDataAction.java     | 46 ++++++++++---------
 ...ransportStartDataFrameAnalyticsAction.java |  2 +-
 .../CategorizeTextAggregatorFactory.java      | 10 ++--
 .../InternalCategorizationAggregation.java    | 12 ++---
 .../InferencePipelineAggregationBuilder.java  |  6 +--
 .../kstest/BucketCountKSTestAggregator.java   |  4 +-
 .../MlAutoscalingDeciderService.java          |  6 +--
 .../extractor/scroll/ScrollDataExtractor.java |  1 +
 .../scroll/ScrollDataExtractorFactory.java    |  8 ++--
 .../dataframe/DataFrameAnalyticsManager.java  | 12 +++--
 .../ml/dataframe/DataFrameAnalyticsTask.java  |  6 +--
 .../extractor/ExtractedFieldsDetector.java    |  4 +-
 .../process/AnalyticsProcessManager.java      |  6 +--
 .../xpack/ml/job/JobManager.java              |  4 +-
 .../ml/job/UpdateJobProcessNotifier.java      |  6 +--
 .../ml/job/persistence/JobDataDeleter.java    | 18 ++++++--
 .../job/persistence/JobResultsPersister.java  | 11 +++--
 .../job/persistence/JobResultsProvider.java   |  2 +-
 .../job/persistence/RecordsQueryBuilder.java  |  4 +-
 .../process/autodetect/ProcessContext.java    |  4 +-
 .../v2/RollupActionSingleNodeTests.java       | 22 +++++----
 .../SearchableSnapshots.java                  |  8 ++--
 .../SearchableSnapshotsStatsResponse.java     |  2 +-
 ...ShardsOnInvalidLicenseClusterListener.java |  6 +--
 ...eSnapshotIndexFoldersDeletionListener.java | 16 +++----
 ...chableSnapshotEnableAllocationDecider.java | 10 ++--
 .../BlobStoreCacheMaintenanceService.java     |  6 +--
 .../cache/common/ByteRange.java               |  4 +-
 .../cache/common/CacheFile.java               | 24 +++++-----
 .../ProgressListenableActionFuture.java       | 44 +++++++++---------
 .../cache/shared/FrozenCacheService.java      | 16 +++----
 .../store/SearchableSnapshotDirectory.java    | 17 +++----
 .../BaseSearchableSnapshotIndexInput.java     | 22 ++++-----
 .../integration/IndexPrivilegeTests.java      |  8 ++--
 .../integration/SecurityClearScrollTests.java |  6 +--
 .../xpack/spatial/common/CartesianPoint.java  |  1 +
 .../index/fielddata/CentroidCalculator.java   | 11 +++--
 .../xpack/spatial/index/fielddata/Extent.java |  1 +
 .../fielddata/GeometryDocValueReader.java     | 10 ++--
 .../index/fielddata/Tile2DVisitor.java        |  7 +--
 .../mapper/LatLonShapeDocValuesQuery.java     |  4 +-
 .../search/aggregations/InternalGeoLine.java  | 14 +++---
 .../geogrid/BoundedGeoTileGridTiler.java      |  7 +--
 .../DelimitedTextStructureFinderFactory.java  |  4 +-
 .../TransformCheckpointServiceNodeTests.java  |  6 +--
 .../xpack/transform/Transform.java            |  6 +--
 .../transforms/ClientTransformIndexer.java    | 10 ++--
 .../transforms/TransformIndexer.java          |  4 +-
 .../transform/transforms/TransformTask.java   | 14 +++---
 .../TransformIndexerStateTests.java           |  4 +-
 .../transforms/TransformIndexerTests.java     |  4 +-
 54 files changed, 275 insertions(+), 238 deletions(-)

diff --git a/build-tools-internal/src/main/resources/checkstyle.xml b/build-tools-internal/src/main/resources/checkstyle.xml
index abc17672311c8..86718f32a9012 100644
--- a/build-tools-internal/src/main/resources/checkstyle.xml
+++ b/build-tools-internal/src/main/resources/checkstyle.xml
@@ -97,6 +97,13 @@
 
     <!-- Checks that a local variable or a parameter does not shadow a field that is defined in the same class. -->
     <!-- Use a forked version that understands setters that don't start with "set". -->
+    <!-- Notes on `ignoredMethodNames`:
+
+        * `createParser` creates objects so should be considered a sort-of constructor
+        * `createComponents` by its nature ends up referring to fields
+          a lot, and there's no benefit to flagging shadowed variables in
+          those methods.
+    -->
     <!-- Disabled until existing violations are fixed -->
     <!--
     <module name="org.elasticsearch.gradle.internal.checkstyle.HiddenFieldCheck">
@@ -107,7 +114,7 @@
         <property name="minLineCount" value="5" />
         <property name="ignoreFormat" value="^(?:threadPool)$"/>
         <property name="ignoreAbstractMethods" value="true"/>
-        <property name="ignoreMethodNames" value="^(?:createParser)$"/>
+        <property name="ignoreMethodNames" value="^(?:createParser|createComponents)$"/>
         <property name="setterCanReturnItsClass" value="true"/>
         <message key="hidden.field" value="''{0}'' hides a field." />
     </module>
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MachineLearning.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MachineLearning.java
index 0a1a714dd5ae8..5e0caca2d165d 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MachineLearning.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MachineLearning.java
@@ -1090,7 +1090,7 @@ public Collection<Module> createGuiceModules() {
 
     @Override
     public List<RestHandler> getRestHandlers(
-        Settings settings,
+        Settings unused,
         RestController restController,
         ClusterSettings clusterSettings,
         IndexScopedSettings indexScopedSettings,
@@ -1264,7 +1264,7 @@ public List<ActionFilter> getActionFilters() {
     }
 
     @Override
-    public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settings) {
+    public List<ExecutorBuilder<?>> getExecutorBuilders(Settings unused) {
         if (false == enabled || transportClientMode) {
             return emptyList();
         }
@@ -1414,7 +1414,7 @@ public List<NamedXContentRegistry.Entry> getNamedXContent() {
     }
 
     @Override
-    public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings settings) {
+    public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings unused) {
         return Collections.unmodifiableList(
             Arrays.asList(
                 SystemIndexDescriptor.builder()
@@ -1695,7 +1695,7 @@ public void cleanUpFeature(
     }
 
     @Override
-    public BreakerSettings getCircuitBreaker(Settings settings) {
+    public BreakerSettings getCircuitBreaker(Settings settingsToUse) {
         return BreakerSettings.updateFromSettings(
             new BreakerSettings(
                 TRAINED_MODEL_CIRCUIT_BREAKER_NAME,
@@ -1704,7 +1704,7 @@ public BreakerSettings getCircuitBreaker(Settings settings) {
                 CircuitBreaker.Type.MEMORY,
                 CircuitBreaker.Durability.TRANSIENT
             ),
-            settings
+            settingsToUse
         );
     }
 
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MlInitializationService.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MlInitializationService.java
index 1177d8fb5efa2..49f95926ebe36 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MlInitializationService.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MlInitializationService.java
@@ -148,7 +148,7 @@ public void clusterChanged(ClusterChangedEvent event) {
 
         // The atomic flag shortcircuits the check after no legacy templates have been found to exist.
         if (this.isMaster && checkForLegacyMlTemplates.get()) {
-            if (deleteOneMlLegacyTemplateIfNecessary(client, event.state()) == false) {
+            if (deleteOneMlLegacyTemplateIfNecessary(event.state()) == false) {
                 checkForLegacyMlTemplates.set(false);
             }
         }
@@ -158,7 +158,7 @@ public void clusterChanged(ClusterChangedEvent event) {
      * @return <code>true</code> if further calls to this method are worthwhile.
      *         <code>false</code> if this method never needs to be called again.
      */
-    private boolean deleteOneMlLegacyTemplateIfNecessary(Client client, ClusterState state) {
+    private boolean deleteOneMlLegacyTemplateIfNecessary(ClusterState state) {
 
         // Don't delete the legacy templates until the entire cluster is on a version that supports composable templates
         if (state.nodes().getMinNodeVersion().before(MlIndexTemplateRegistry.COMPOSABLE_TEMPLATE_SWITCH_VERSION)) {
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportDeleteExpiredDataAction.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportDeleteExpiredDataAction.java
index faa4829cfb37c..7f03566283cd2 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportDeleteExpiredDataAction.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportDeleteExpiredDataAction.java
@@ -132,10 +132,10 @@ protected void doExecute(
         TaskId taskId = new TaskId(clusterService.localNode().getId(), task.getId());
 
         BooleanSupplier isTimedOutSupplier = () -> Instant.now(clock).isAfter(timeoutTime);
-        AnomalyDetectionAuditor auditor = new AnomalyDetectionAuditor(client, clusterService);
+        AnomalyDetectionAuditor anomalyDetectionAuditor = new AnomalyDetectionAuditor(client, clusterService);
 
         if (Strings.isNullOrEmpty(request.getJobId()) || Strings.isAllOrWildcard(request.getJobId())) {
-            List<MlDataRemover> dataRemovers = createDataRemovers(client, taskId, auditor);
+            List<MlDataRemover> dataRemovers = createDataRemovers(client, taskId, anomalyDetectionAuditor);
             threadPool.executor(MachineLearning.UTILITY_THREAD_POOL_NAME)
                 .execute(() -> deleteExpiredData(request, dataRemovers, listener, isTimedOutSupplier));
         } else {
@@ -144,7 +144,7 @@ protected void doExecute(
                     List<Job> jobs = jobBuilders.stream().map(Job.Builder::build).collect(Collectors.toList());
                     String[] jobIds = jobs.stream().map(Job::getId).toArray(String[]::new);
                     request.setExpandedJobIds(jobIds);
-                    List<MlDataRemover> dataRemovers = createDataRemovers(jobs, taskId, auditor);
+                    List<MlDataRemover> dataRemovers = createDataRemovers(jobs, taskId, anomalyDetectionAuditor);
                     deleteExpiredData(request, dataRemovers, listener, isTimedOutSupplier);
                 });
             }, listener::onFailure));
@@ -232,40 +232,44 @@ void deleteExpiredData(
         }
     }
 
-    private List<MlDataRemover> createDataRemovers(OriginSettingClient client, TaskId parentTaskId, AnomalyDetectionAuditor auditor) {
+    private List<MlDataRemover> createDataRemovers(
+        OriginSettingClient originClient,
+        TaskId parentTaskId,
+        AnomalyDetectionAuditor anomalyDetectionAuditor
+    ) {
         return Arrays.asList(
             new ExpiredResultsRemover(
-                client,
-                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(client)),
+                originClient,
+                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(originClient)),
                 parentTaskId,
-                auditor,
+                anomalyDetectionAuditor,
                 threadPool
             ),
-            new ExpiredForecastsRemover(client, threadPool, parentTaskId),
+            new ExpiredForecastsRemover(originClient, threadPool, parentTaskId),
             new ExpiredModelSnapshotsRemover(
-                client,
-                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(client)),
+                originClient,
+                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(originClient)),
                 threadPool,
                 parentTaskId,
                 jobResultsProvider,
-                auditor
+                anomalyDetectionAuditor
             ),
-            new UnusedStateRemover(client, clusterService, parentTaskId),
-            new EmptyStateIndexRemover(client, parentTaskId),
-            new UnusedStatsRemover(client, parentTaskId),
+            new UnusedStateRemover(originClient, clusterService, parentTaskId),
+            new EmptyStateIndexRemover(originClient, parentTaskId),
+            new UnusedStatsRemover(originClient, parentTaskId),
             new ExpiredAnnotationsRemover(
-                client,
-                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(client)),
+                originClient,
+                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(originClient)),
                 parentTaskId,
-                auditor,
+                anomalyDetectionAuditor,
                 threadPool
             )
         );
     }
 
-    private List<MlDataRemover> createDataRemovers(List<Job> jobs, TaskId parentTaskId, AnomalyDetectionAuditor auditor) {
+    private List<MlDataRemover> createDataRemovers(List<Job> jobs, TaskId parentTaskId, AnomalyDetectionAuditor anomalyDetectionAuditor) {
         return Arrays.asList(
-            new ExpiredResultsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, auditor, threadPool),
+            new ExpiredResultsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, anomalyDetectionAuditor, threadPool),
             new ExpiredForecastsRemover(client, threadPool, parentTaskId),
             new ExpiredModelSnapshotsRemover(
                 client,
@@ -273,12 +277,12 @@ private List<MlDataRemover> createDataRemovers(List<Job> jobs, TaskId parentTask
                 threadPool,
                 parentTaskId,
                 jobResultsProvider,
-                auditor
+                anomalyDetectionAuditor
             ),
             new UnusedStateRemover(client, clusterService, parentTaskId),
             new EmptyStateIndexRemover(client, parentTaskId),
             new UnusedStatsRemover(client, parentTaskId),
-            new ExpiredAnnotationsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, auditor, threadPool)
+            new ExpiredAnnotationsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, anomalyDetectionAuditor, threadPool)
         );
     }
 
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportStartDataFrameAnalyticsAction.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportStartDataFrameAnalyticsAction.java
index 61ced5ff02962..68f41d1d4be9a 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportStartDataFrameAnalyticsAction.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportStartDataFrameAnalyticsAction.java
@@ -689,7 +689,7 @@ protected AllocatedPersistentTask createTask(
         public PersistentTasksCustomMetadata.Assignment getAssignment(
             TaskParams params,
             Collection<DiscoveryNode> candidateNodes,
-            ClusterState clusterState
+            @SuppressWarnings("HiddenField") ClusterState clusterState
         ) {
             boolean isMemoryTrackerRecentlyRefreshed = memoryTracker.isRecentlyRefreshed();
             Optional<PersistentTasksCustomMetadata.Assignment> optionalAssignment = getPotentialAssignment(
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/CategorizeTextAggregatorFactory.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/CategorizeTextAggregatorFactory.java
index 24d22d22fd78b..ca56741796ae3 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/CategorizeTextAggregatorFactory.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/CategorizeTextAggregatorFactory.java
@@ -97,15 +97,15 @@ protected Aggregator createInternal(Aggregator parent, CardinalityUpperBound car
                     + "]"
             );
         }
-        TermsAggregator.BucketCountThresholds bucketCountThresholds = new TermsAggregator.BucketCountThresholds(this.bucketCountThresholds);
-        if (bucketCountThresholds.getShardSize() == CategorizeTextAggregationBuilder.DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
+        TermsAggregator.BucketCountThresholds thresholds = new TermsAggregator.BucketCountThresholds(this.bucketCountThresholds);
+        if (thresholds.getShardSize() == CategorizeTextAggregationBuilder.DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
             // The user has not made a shardSize selection. Use default
             // heuristic to avoid any wrong-ranking caused by distributed
             // counting
             // TODO significant text does a 2x here, should we as well?
-            bucketCountThresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize()));
+            thresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(thresholds.getRequiredSize()));
         }
-        bucketCountThresholds.ensureValidity();
+        thresholds.ensureValidity();
 
         return new CategorizeTextAggregator(
             name,
@@ -114,7 +114,7 @@ protected Aggregator createInternal(Aggregator parent, CardinalityUpperBound car
             parent,
             indexedFieldName,
             fieldType,
-            bucketCountThresholds,
+            thresholds,
             maxUniqueTokens,
             maxMatchTokens,
             similarityThreshold,
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java
index d90dbda4c7e56..5c1c4588579f4 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java
@@ -55,14 +55,14 @@ public long getDocCount() {
             return docCount;
         }
 
-        public Bucket reduce(BucketKey key, ReduceContext reduceContext) {
+        public Bucket reduce(BucketKey bucketKey, ReduceContext reduceContext) {
             List<InternalAggregations> innerAggs = new ArrayList<>(toReduce.size());
-            long docCount = 0;
+            long totalDocCount = 0;
             for (Bucket bucket : toReduce) {
                 innerAggs.add(bucket.aggregations);
-                docCount += bucket.docCount;
+                totalDocCount += bucket.docCount;
             }
-            return new Bucket(key, docCount, InternalAggregations.reduce(innerAggs, reduceContext));
+            return new Bucket(bucketKey, totalDocCount, InternalAggregations.reduce(innerAggs, reduceContext));
         }
 
         public DelayedCategorizationBucket add(Bucket bucket) {
@@ -339,7 +339,7 @@ public XContentBuilder doXContentBody(XContentBuilder builder, Params params) th
     }
 
     @Override
-    public InternalCategorizationAggregation create(List<Bucket> buckets) {
+    public InternalCategorizationAggregation create(List<Bucket> bucketList) {
         return new InternalCategorizationAggregation(
             name,
             requiredSize,
@@ -348,7 +348,7 @@ public InternalCategorizationAggregation create(List<Bucket> buckets) {
             maxMatchTokens,
             similarityThreshold,
             super.metadata,
-            buckets
+            bucketList
         );
     }
 
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/inference/InferencePipelineAggregationBuilder.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/inference/InferencePipelineAggregationBuilder.java
index 65cf75f99073e..fd1a173992778 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/inference/InferencePipelineAggregationBuilder.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/inference/InferencePipelineAggregationBuilder.java
@@ -249,11 +249,11 @@ public InferencePipelineAggregationBuilder rewrite(QueryRewriteContext context)
 
         SetOnce<LocalModel> loadedModel = new SetOnce<>();
         BiConsumer<Client, ActionListener<?>> modelLoadAction = (client, listener) -> modelLoadingService.get()
-            .getModelForSearch(modelId, listener.delegateFailure((delegate, model) -> {
-                loadedModel.set(model);
+            .getModelForSearch(modelId, listener.delegateFailure((delegate, localModel) -> {
+                loadedModel.set(localModel);
 
                 boolean isLicensed = MachineLearningField.ML_API_FEATURE.check(licenseState)
-                    || licenseState.isAllowedByLicense(model.getLicenseLevel());
+                    || licenseState.isAllowedByLicense(localModel.getLicenseLevel());
                 if (isLicensed) {
                     delegate.onResponse(null);
                 } else {
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/kstest/BucketCountKSTestAggregator.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/kstest/BucketCountKSTestAggregator.java
index 9d404697028d6..05293ac8c5440 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/kstest/BucketCountKSTestAggregator.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/kstest/BucketCountKSTestAggregator.java
@@ -248,7 +248,7 @@ public InternalAggregation doReduce(Aggregations aggregations, InternalAggregati
             );
         }
         final MlAggsHelper.DoubleBucketValues bucketsValue = maybeBucketsValue.get();
-        double[] fractions = this.fractions == null
+        double[] fractionsArr = this.fractions == null
             ? DoubleStream.concat(
                 DoubleStream.of(0.0),
                 Stream.generate(() -> 1.0 / (bucketsValue.getDocCounts().length - 1))
@@ -258,6 +258,6 @@ public InternalAggregation doReduce(Aggregations aggregations, InternalAggregati
             // We prepend zero to the fractions as we prepend 0 to the doc counts and we want them to be the same length when
             // we create the monotonically increasing values for distribution comparison.
             : DoubleStream.concat(DoubleStream.of(0.0), Arrays.stream(this.fractions)).toArray();
-        return new InternalKSTestAggregation(name(), metadata(), ksTest(fractions, bucketsValue, alternatives, samplingMethod));
+        return new InternalKSTestAggregation(name(), metadata(), ksTest(fractionsArr, bucketsValue, alternatives, samplingMethod));
     }
 }
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/autoscaling/MlAutoscalingDeciderService.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/autoscaling/MlAutoscalingDeciderService.java
index 92cf5d60f4211..1abd1b6ad7ef2 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/autoscaling/MlAutoscalingDeciderService.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/autoscaling/MlAutoscalingDeciderService.java
@@ -559,15 +559,15 @@ public AutoscalingDeciderResult scale(Settings configuration, AutoscalingDecider
             if (nodeLoads.size() > 1) {
                 long totalAssignedJobs = nodeLoads.stream().mapToLong(NodeLoad::getNumAssignedJobs).sum();
                 // one volatile read
-                long maxOpenJobs = this.maxOpenJobs;
-                if (totalAssignedJobs > maxOpenJobs) {
+                long maxOpenJobsCopy = this.maxOpenJobs;
+                if (totalAssignedJobs > maxOpenJobsCopy) {
                     String msg = String.format(
                         Locale.ROOT,
                         "not scaling down as the total number of jobs [%d] exceeds the setting [%s (%d)]. "
                             + " To allow a scale down [%s] must be increased.",
                         totalAssignedJobs,
                         MAX_OPEN_JOBS_PER_NODE.getKey(),
-                        maxOpenJobs,
+                        maxOpenJobsCopy,
                         MAX_OPEN_JOBS_PER_NODE.getKey()
                     );
                     logger.info(
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractor.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractor.java
index df711b88926d5..0870053d24bc9 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractor.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractor.java
@@ -211,6 +211,7 @@ void markScrollAsErrored() {
         searchHasShardFailure = true;
     }
 
+    @SuppressWarnings("HiddenField")
     protected SearchResponse executeSearchScrollRequest(String scrollId) {
         return ClientHelper.executeWithHeaders(
             context.headers,
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractorFactory.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractorFactory.java
index dc117ba5ffe04..553147a804e23 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractorFactory.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractorFactory.java
@@ -77,12 +77,10 @@ public static void create(
         ActionListener<DataExtractorFactory> listener
     ) {
 
-        // Step 2. Contruct the factory and notify listener
+        // Step 2. Construct the factory and notify listener
         ActionListener<FieldCapabilitiesResponse> fieldCapabilitiesHandler = ActionListener.wrap(fieldCapabilitiesResponse -> {
-            TimeBasedExtractedFields extractedFields = TimeBasedExtractedFields.build(job, datafeed, fieldCapabilitiesResponse);
-            listener.onResponse(
-                new ScrollDataExtractorFactory(client, datafeed, job, extractedFields, xContentRegistry, timingStatsReporter)
-            );
+            TimeBasedExtractedFields fields = TimeBasedExtractedFields.build(job, datafeed, fieldCapabilitiesResponse);
+            listener.onResponse(new ScrollDataExtractorFactory(client, datafeed, job, fields, xContentRegistry, timingStatsReporter));
         }, e -> {
             Throwable cause = ExceptionsHelper.unwrapCause(e);
             if (cause instanceof IndexNotFoundException) {
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsManager.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsManager.java
index 2c8a72c79d6fd..e74945f13c63d 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsManager.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsManager.java
@@ -153,7 +153,7 @@ public void execute(DataFrameAnalyticsTask task, ClusterState clusterState, Time
     }
 
     private void createStatsIndexAndUpdateMappingsIfNecessary(
-        Client client,
+        Client clientToUse,
         ClusterState clusterState,
         TimeValue masterNodeTimeout,
         ActionListener<Boolean> listener
@@ -162,7 +162,7 @@ private void createStatsIndexAndUpdateMappingsIfNecessary(
             aBoolean -> ElasticsearchMappings.addDocMappingIfMissing(
                 MlStatsIndex.writeAlias(),
                 MlStatsIndex::wrappedMapping,
-                client,
+                clientToUse,
                 clusterState,
                 masterNodeTimeout,
                 listener
@@ -170,7 +170,13 @@ private void createStatsIndexAndUpdateMappingsIfNecessary(
             listener::onFailure
         );
 
-        MlStatsIndex.createStatsIndexAndAliasIfNecessary(client, clusterState, expressionResolver, masterNodeTimeout, createIndexListener);
+        MlStatsIndex.createStatsIndexAndAliasIfNecessary(
+            clientToUse,
+            clusterState,
+            expressionResolver,
+            masterNodeTimeout,
+            createIndexListener
+        );
     }
 
     private void determineProgressAndResume(DataFrameAnalyticsTask task, DataFrameAnalyticsConfig config) {
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsTask.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsTask.java
index f3eb9f6a954e4..c01a38ab820c2 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsTask.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsTask.java
@@ -213,7 +213,7 @@ public void persistProgress(Runnable runnable) {
     }
 
     // Visible for testing
-    void persistProgress(Client client, String jobId, Runnable runnable) {
+    void persistProgress(Client clientToUse, String jobId, Runnable runnable) {
         LOGGER.debug("[{}] Persisting progress", jobId);
 
         SetOnce<StoredProgress> storedProgress = new SetOnce<>();
@@ -266,7 +266,7 @@ void persistProgress(Client client, String jobId, Runnable runnable) {
                 storedProgress.get().toXContent(jsonBuilder, Payload.XContent.EMPTY_PARAMS);
                 indexRequest.source(jsonBuilder);
             }
-            executeAsyncWithOrigin(client, ML_ORIGIN, IndexAction.INSTANCE, indexRequest, indexProgressDocListener);
+            executeAsyncWithOrigin(clientToUse, ML_ORIGIN, IndexAction.INSTANCE, indexRequest, indexProgressDocListener);
         }, e -> {
             LOGGER.error(
                 new ParameterizedMessage(
@@ -283,7 +283,7 @@ void persistProgress(Client client, String jobId, Runnable runnable) {
             SearchRequest searchRequest = new SearchRequest(AnomalyDetectorsIndex.jobStateIndexPattern()).source(
                 new SearchSourceBuilder().size(1).query(new IdsQueryBuilder().addIds(progressDocId))
             );
-            executeAsyncWithOrigin(client, ML_ORIGIN, SearchAction.INSTANCE, searchRequest, searchFormerProgressDocListener);
+            executeAsyncWithOrigin(clientToUse, ML_ORIGIN, SearchAction.INSTANCE, searchRequest, searchFormerProgressDocListener);
         }, e -> {
             LOGGER.error(
                 new ParameterizedMessage(
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/extractor/ExtractedFieldsDetector.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/extractor/ExtractedFieldsDetector.java
index f4c0d047231fb..2a62a9da6be13 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/extractor/ExtractedFieldsDetector.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/extractor/ExtractedFieldsDetector.java
@@ -82,8 +82,8 @@ public class ExtractedFieldsDetector {
         this.topNestedFieldPrefixes = findTopNestedFieldPrefixes(fieldCapabilitiesResponse);
     }
 
-    private List<String> findTopNestedFieldPrefixes(FieldCapabilitiesResponse fieldCapabilitiesResponse) {
-        List<String> sortedNestedFieldPrefixes = fieldCapabilitiesResponse.get()
+    private List<String> findTopNestedFieldPrefixes(FieldCapabilitiesResponse response) {
+        List<String> sortedNestedFieldPrefixes = response.get()
             .keySet()
             .stream()
             .filter(field -> isNested(getMappingTypes(field)))
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/process/AnalyticsProcessManager.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/process/AnalyticsProcessManager.java
index 0f5511f68f0e4..e122f99c744c6 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/process/AnalyticsProcessManager.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/process/AnalyticsProcessManager.java
@@ -461,9 +461,9 @@ synchronized boolean startProcess(
             return true;
         }
 
-        private AnalyticsProcessConfig createProcessConfig(DataFrameDataExtractor dataExtractor, ExtractedFields extractedFields) {
-            DataFrameDataExtractor.DataSummary dataSummary = dataExtractor.collectDataSummary();
-            Set<String> categoricalFields = dataExtractor.getCategoricalFields(config.getAnalysis());
+        private AnalyticsProcessConfig createProcessConfig(DataFrameDataExtractor extractor, ExtractedFields extractedFields) {
+            DataFrameDataExtractor.DataSummary dataSummary = extractor.collectDataSummary();
+            Set<String> categoricalFields = extractor.getCategoricalFields(config.getAnalysis());
             int threads = Math.min(config.getMaxNumThreads(), numAllocatedProcessors);
             return new AnalyticsProcessConfig(
                 config.getId(),
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java
index 605193acef0dd..bed93e2bc26a0 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java
@@ -471,7 +471,7 @@ public void deleteJob(DeleteJobAction.Request request, ClusterState state, Actio
 
     public void deleteJob(
         DeleteJobAction.Request request,
-        Client client,
+        Client clientToUse,
         ClusterState state,
         ActionListener<AcknowledgedResponse> listener
     ) {
@@ -505,7 +505,7 @@ public void deleteJob(
         );
 
         // Step 1. Delete the physical storage
-        new JobDataDeleter(client, jobId).deleteJobDocuments(
+        new JobDataDeleter(clientToUse, jobId).deleteJobDocuments(
             jobConfigProvider,
             indexNameExpressionResolver,
             state,
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/UpdateJobProcessNotifier.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/UpdateJobProcessNotifier.java
index b03b8bf87c24d..d824f17304e94 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/UpdateJobProcessNotifier.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/UpdateJobProcessNotifier.java
@@ -85,9 +85,9 @@ private void start() {
     private void stop() {
         orderedJobUpdates.clear();
 
-        ThreadPool.Cancellable cancellable = this.cancellable;
-        if (cancellable != null) {
-            cancellable.cancel();
+        ThreadPool.Cancellable cancellableCopy = this.cancellable;
+        if (cancellableCopy != null) {
+            cancellableCopy.cancel();
         }
     }
 
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobDataDeleter.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobDataDeleter.java
index 15c398596aabb..c7fbc908a668a 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobDataDeleter.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobDataDeleter.java
@@ -421,7 +421,11 @@ public void deleteJobDocuments(
         deleteModelState(jobId, deleteStateHandler);
     }
 
-    private void deleteResultsByQuery(String jobId, String[] indices, ActionListener<BulkByScrollResponse> listener) {
+    private void deleteResultsByQuery(
+        @SuppressWarnings("HiddenField") String jobId,
+        String[] indices,
+        ActionListener<BulkByScrollResponse> listener
+    ) {
         assert indices.length > 0;
 
         ActionListener<RefreshResponse> refreshListener = ActionListener.wrap(refreshResponse -> {
@@ -442,7 +446,7 @@ private void deleteResultsByQuery(String jobId, String[] indices, ActionListener
         executeAsyncWithOrigin(client, ML_ORIGIN, RefreshAction.INSTANCE, refreshRequest, refreshListener);
     }
 
-    private void deleteAliases(String jobId, ActionListener<AcknowledgedResponse> finishedHandler) {
+    private void deleteAliases(@SuppressWarnings("HiddenField") String jobId, ActionListener<AcknowledgedResponse> finishedHandler) {
         final String readAliasName = AnomalyDetectorsIndex.jobResultsAliasedName(jobId);
         final String writeAliasName = AnomalyDetectorsIndex.resultsWriteAlias(jobId);
 
@@ -494,7 +498,7 @@ private IndicesAliasesRequest buildRemoveAliasesRequest(GetAliasesResponse getAl
             );
     }
 
-    private void deleteQuantiles(String jobId, ActionListener<Boolean> finishedHandler) {
+    private void deleteQuantiles(@SuppressWarnings("HiddenField") String jobId, ActionListener<Boolean> finishedHandler) {
         // Just use ID here, not type, as trying to delete different types spams the logs with an exception stack trace
         IdsQueryBuilder query = new IdsQueryBuilder().addIds(Quantiles.documentId(jobId));
         DeleteByQueryRequest request = new DeleteByQueryRequest(AnomalyDetectorsIndex.jobStateIndexPattern()).setQuery(query)
@@ -511,7 +515,7 @@ private void deleteQuantiles(String jobId, ActionListener<Boolean> finishedHandl
         );
     }
 
-    private void deleteModelState(String jobId, ActionListener<BulkByScrollResponse> listener) {
+    private void deleteModelState(@SuppressWarnings("HiddenField") String jobId, ActionListener<BulkByScrollResponse> listener) {
         GetModelSnapshotsAction.Request request = new GetModelSnapshotsAction.Request(jobId, null);
         request.setPageParams(new PageParams(0, MAX_SNAPSHOTS_TO_DELETE));
         executeAsyncWithOrigin(client, ML_ORIGIN, GetModelSnapshotsAction.INSTANCE, request, ActionListener.wrap(response -> {
@@ -520,7 +524,11 @@ private void deleteModelState(String jobId, ActionListener<BulkByScrollResponse>
         }, listener::onFailure));
     }
 
-    private void deleteCategorizerState(String jobId, int docNum, ActionListener<Boolean> finishedHandler) {
+    private void deleteCategorizerState(
+        @SuppressWarnings("HiddenField") String jobId,
+        int docNum,
+        ActionListener<Boolean> finishedHandler
+    ) {
         // Just use ID here, not type, as trying to delete different types spams the logs with an exception stack trace
         IdsQueryBuilder query = new IdsQueryBuilder().addIds(CategorizerState.documentId(jobId, docNum));
         DeleteByQueryRequest request = new DeleteByQueryRequest(AnomalyDetectorsIndex.jobStateIndexPattern()).setQuery(query)
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsPersister.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsPersister.java
index f9c9079b797e0..15de78dc68118 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsPersister.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsPersister.java
@@ -132,7 +132,10 @@ public Builder persistBucket(Bucket bucket) {
             return this;
         }
 
-        private void persistBucketInfluencersStandalone(String jobId, List<BucketInfluencer> bucketInfluencers) {
+        private void persistBucketInfluencersStandalone(
+            @SuppressWarnings("HiddenField") String jobId,
+            List<BucketInfluencer> bucketInfluencers
+        ) {
             if (bucketInfluencers != null && bucketInfluencers.isEmpty() == false) {
                 for (BucketInfluencer bucketInfluencer : bucketInfluencers) {
                     String id = bucketInfluencer.getId();
@@ -508,7 +511,7 @@ void setRefreshPolicy(WriteRequest.RefreshPolicy refreshPolicy) {
         }
 
         BulkResponse persist(Supplier<Boolean> shouldRetry, boolean requireAlias) {
-            logCall(indexName);
+            logCall();
             try {
                 return resultsPersisterService.indexWithRetry(
                     jobId,
@@ -533,7 +536,7 @@ BulkResponse persist(Supplier<Boolean> shouldRetry, boolean requireAlias) {
         }
 
         void persist(ActionListener<IndexResponse> listener, boolean requireAlias) {
-            logCall(indexName);
+            logCall();
 
             try (XContentBuilder content = toXContentBuilder(object, params)) {
                 IndexRequest indexRequest = new IndexRequest(indexName).id(id)
@@ -549,7 +552,7 @@ void persist(ActionListener<IndexResponse> listener, boolean requireAlias) {
             }
         }
 
-        private void logCall(String indexName) {
+        private void logCall() {
             if (logger.isTraceEnabled()) {
                 if (id != null) {
                     logger.trace("[{}] ES API CALL: to index {} with ID [{}]", jobId, indexName, id);
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsProvider.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsProvider.java
index 39ecc57cd6230..d09773875bf9a 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsProvider.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobResultsProvider.java
@@ -783,7 +783,7 @@ public void buckets(
         BucketsQueryBuilder query,
         Consumer<QueryPage<Bucket>> handler,
         Consumer<Exception> errorHandler,
-        Client client
+        @SuppressWarnings("HiddenField") Client client
     ) throws ResourceNotFoundException {
 
         String indexName = AnomalyDetectorsIndex.jobResultsAliasedName(jobId);
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/RecordsQueryBuilder.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/RecordsQueryBuilder.java
index 865660edb8242..9ccaed707e7aa 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/RecordsQueryBuilder.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/persistence/RecordsQueryBuilder.java
@@ -137,8 +137,8 @@ public SearchSourceBuilder build() {
             .sort(sb)
             .fetchSource(true);
 
-        for (String sortField : SECONDARY_SORT) {
-            searchSourceBuilder.sort(sortField, sortDescending ? SortOrder.DESC : SortOrder.ASC);
+        for (String eachSortField : SECONDARY_SORT) {
+            searchSourceBuilder.sort(eachSortField, sortDescending ? SortOrder.DESC : SortOrder.ASC);
         }
 
         return searchSourceBuilder;
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/ProcessContext.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/ProcessContext.java
index 4d79873d01831..49b02bdd6ae74 100644
--- a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/ProcessContext.java
+++ b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/ProcessContext.java
@@ -69,9 +69,9 @@ void unlock() {
         lock.unlock();
     }
 
-    void setRunning(AutodetectCommunicator autodetectCommunicator) {
+    void setRunning(AutodetectCommunicator communicator) {
         assert lock.isHeldByCurrentThread();
-        state.setRunning(this, autodetectCommunicator);
+        state.setRunning(this, communicator);
     }
 
     boolean setDying() {
diff --git a/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/v2/RollupActionSingleNodeTests.java b/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/v2/RollupActionSingleNodeTests.java
index b600780702acb..cd48f7fc32fee 100644
--- a/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/v2/RollupActionSingleNodeTests.java
+++ b/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/v2/RollupActionSingleNodeTests.java
@@ -427,37 +427,41 @@ private RolloverResponse rollover(String dataStreamName) throws ExecutionExcepti
     }
 
     @SuppressWarnings("unchecked")
-    private void assertRollupIndex(RollupActionConfig config, String sourceIndex, String rollupIndex) {
+    private void assertRollupIndex(RollupActionConfig config, String sourceIndex, String rollupIndexName) {
         final CompositeAggregationBuilder aggregation = buildCompositeAggs("resp", config);
         long numBuckets = 0;
         InternalComposite origResp = client().prepareSearch(sourceIndex).addAggregation(aggregation).get().getAggregations().get("resp");
-        InternalComposite rollupResp = client().prepareSearch(rollupIndex).addAggregation(aggregation).get().getAggregations().get("resp");
+        InternalComposite rollupResp = client().prepareSearch(rollupIndexName)
+            .addAggregation(aggregation)
+            .get()
+            .getAggregations()
+            .get("resp");
         while (origResp.afterKey() != null) {
             numBuckets += origResp.getBuckets().size();
             assertThat(origResp, equalTo(rollupResp));
             aggregation.aggregateAfter(origResp.afterKey());
             origResp = client().prepareSearch(sourceIndex).addAggregation(aggregation).get().getAggregations().get("resp");
-            rollupResp = client().prepareSearch(rollupIndex).addAggregation(aggregation).get().getAggregations().get("resp");
+            rollupResp = client().prepareSearch(rollupIndexName).addAggregation(aggregation).get().getAggregations().get("resp");
         }
         assertThat(origResp, equalTo(rollupResp));
 
-        SearchResponse resp = client().prepareSearch(rollupIndex).setTrackTotalHits(true).get();
+        SearchResponse resp = client().prepareSearch(rollupIndexName).setTrackTotalHits(true).get();
         assertThat(resp.getHits().getTotalHits().value, equalTo(numBuckets));
 
-        GetIndexResponse indexSettingsResp = client().admin().indices().prepareGetIndex().addIndices(sourceIndex, rollupIndex).get();
+        GetIndexResponse indexSettingsResp = client().admin().indices().prepareGetIndex().addIndices(sourceIndex, rollupIndexName).get();
         // Assert rollup metadata are set in index settings
         assertEquals(
             indexSettingsResp.getSetting(sourceIndex, "index.uuid"),
-            indexSettingsResp.getSetting(rollupIndex, "index.rollup.source.uuid")
+            indexSettingsResp.getSetting(rollupIndexName, "index.rollup.source.uuid")
         );
         assertEquals(
             indexSettingsResp.getSetting(sourceIndex, "index.provided_name"),
-            indexSettingsResp.getSetting(rollupIndex, "index.rollup.source.name")
+            indexSettingsResp.getSetting(rollupIndexName, "index.rollup.source.name")
         );
 
         // Assert field mappings
         Map<String, Map<String, Object>> mappings = (Map<String, Map<String, Object>>) indexSettingsResp.getMappings()
-            .get(rollupIndex)
+            .get(rollupIndexName)
             .get("_doc")
             .getSourceAsMap()
             .get("properties");
@@ -499,7 +503,7 @@ private void assertRollupIndex(RollupActionConfig config, String sourceIndex, St
         // Assert that temporary index was removed
         expectThrows(
             IndexNotFoundException.class,
-            () -> client().admin().indices().prepareGetIndex().addIndices(".rolluptmp-" + rollupIndex).get()
+            () -> client().admin().indices().prepareGetIndex().addIndices(".rolluptmp-" + rollupIndexName).get()
         );
     }
 
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java
index c3b44782f0d6d..179e9ca019047 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java
@@ -404,7 +404,7 @@ public List<IndexFoldersDeletionListener> getIndexFoldersDeletionListeners() {
     }
 
     @Override
-    public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings settings) {
+    public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings unused) {
         return org.elasticsearch.core.List.of(
             SystemIndexDescriptor.builder()
                 .setIndexPattern(SNAPSHOT_BLOB_CACHE_INDEX_PATTERN)
@@ -519,7 +519,7 @@ public Map<String, SnapshotCommitSupplier> getSnapshotCommitSuppliers() {
     }
 
     public List<RestHandler> getRestHandlers(
-        Settings settings,
+        Settings unused,
         RestController restController,
         ClusterSettings clusterSettings,
         IndexScopedSettings indexScopedSettings,
@@ -547,11 +547,11 @@ protected XPackLicenseState getLicenseState() {
     }
 
     @Override
-    public Collection<AllocationDecider> createAllocationDeciders(Settings settings, ClusterSettings clusterSettings) {
+    public Collection<AllocationDecider> createAllocationDeciders(Settings settingsToUse, ClusterSettings clusterSettings) {
         return org.elasticsearch.core.List.of(
             new SearchableSnapshotAllocationDecider(() -> SEARCHABLE_SNAPSHOT_FEATURE.checkWithoutTracking(getLicenseState())),
             new SearchableSnapshotRepositoryExistsAllocationDecider(),
-            new SearchableSnapshotEnableAllocationDecider(settings, clusterSettings),
+            new SearchableSnapshotEnableAllocationDecider(settingsToUse, clusterSettings),
             new HasFrozenCacheAllocationDecider(frozenCacheInfoService),
             new DedicatedFrozenNodeAllocationDecider()
         );
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/action/SearchableSnapshotsStatsResponse.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/action/SearchableSnapshotsStatsResponse.java
index 304054b9ceca1..c0017983cc139 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/action/SearchableSnapshotsStatsResponse.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/action/SearchableSnapshotsStatsResponse.java
@@ -94,7 +94,7 @@ protected void addCustomXContentFields(XContentBuilder builder, Params params) t
         if ("indices".equalsIgnoreCase(level) || "shards".equalsIgnoreCase(level)) {
             builder.startObject("indices");
             final List<Index> indices = getStats().stream()
-                .filter(stats -> stats.getStats().isEmpty() == false)
+                .filter(shardStats -> shardStats.getStats().isEmpty() == false)
                 .map(SearchableSnapshotShardStats::getShardRouting)
                 .map(ShardRouting::index)
                 .sorted(Comparator.comparing(Index::getName))
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/FailShardsOnInvalidLicenseClusterListener.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/FailShardsOnInvalidLicenseClusterListener.java
index d7ad0865b207e..beb5e5c727e3a 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/FailShardsOnInvalidLicenseClusterListener.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/FailShardsOnInvalidLicenseClusterListener.java
@@ -62,8 +62,8 @@ public synchronized void beforeIndexShardClosed(ShardId shardId, @Nullable Index
 
     @Override
     public synchronized void licenseStateChanged() {
-        final boolean allowed = SEARCHABLE_SNAPSHOT_FEATURE.checkWithoutTracking(xPackLicenseState);
-        if (allowed && this.allowed == false) {
+        final boolean isAllowed = SEARCHABLE_SNAPSHOT_FEATURE.checkWithoutTracking(xPackLicenseState);
+        if (isAllowed && this.allowed == false) {
             rerouteService.reroute("reroute after license activation", Priority.NORMAL, new ActionListener<ClusterState>() {
                 @Override
                 public void onResponse(ClusterState clusterState) {
@@ -76,7 +76,7 @@ public void onFailure(Exception e) {
                 }
             });
         }
-        this.allowed = allowed;
+        this.allowed = isAllowed;
         failActiveShardsIfNecessary();
     }
 
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/SearchableSnapshotIndexFoldersDeletionListener.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/SearchableSnapshotIndexFoldersDeletionListener.java
index bc41b2c7f0c4c..3805e965c1b07 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/SearchableSnapshotIndexFoldersDeletionListener.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/SearchableSnapshotIndexFoldersDeletionListener.java
@@ -33,15 +33,15 @@ public class SearchableSnapshotIndexFoldersDeletionListener implements IndexStor
 
     private static final Logger logger = LogManager.getLogger(SearchableSnapshotIndexEventListener.class);
 
-    private final Supplier<CacheService> cacheService;
-    private final Supplier<FrozenCacheService> frozenCacheService;
+    private final Supplier<CacheService> cacheServiceSupplier;
+    private final Supplier<FrozenCacheService> frozenCacheServiceSupplier;
 
     public SearchableSnapshotIndexFoldersDeletionListener(
-        Supplier<CacheService> cacheService,
-        Supplier<FrozenCacheService> frozenCacheService
+        Supplier<CacheService> cacheServiceSupplier,
+        Supplier<FrozenCacheService> frozenCacheServiceSupplier
     ) {
-        this.cacheService = Objects.requireNonNull(cacheService);
-        this.frozenCacheService = Objects.requireNonNull(frozenCacheService);
+        this.cacheServiceSupplier = Objects.requireNonNull(cacheServiceSupplier);
+        this.frozenCacheServiceSupplier = Objects.requireNonNull(frozenCacheServiceSupplier);
     }
 
     @Override
@@ -61,7 +61,7 @@ public void beforeShardFoldersDeleted(ShardId shardId, IndexSettings indexSettin
     }
 
     private void markShardAsEvictedInCache(ShardId shardId, IndexSettings indexSettings) {
-        final CacheService cacheService = this.cacheService.get();
+        final CacheService cacheService = this.cacheServiceSupplier.get();
         assert cacheService != null : "cache service not initialized";
 
         logger.debug("{} marking shard as evicted in searchable snapshots cache (reason: cache files deleted from disk)", shardId);
@@ -71,7 +71,7 @@ private void markShardAsEvictedInCache(ShardId shardId, IndexSettings indexSetti
             shardId
         );
 
-        final FrozenCacheService frozenCacheService = this.frozenCacheService.get();
+        final FrozenCacheService frozenCacheService = this.frozenCacheServiceSupplier.get();
         assert frozenCacheService != null : "frozen cache service not initialized";
         frozenCacheService.markShardAsEvictedInCache(
             SNAPSHOT_SNAPSHOT_ID_SETTING.get(indexSettings.getSettings()),
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/decider/SearchableSnapshotEnableAllocationDecider.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/decider/SearchableSnapshotEnableAllocationDecider.java
index 938feb0303409..c2a02acb3b8ba 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/decider/SearchableSnapshotEnableAllocationDecider.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/decider/SearchableSnapshotEnableAllocationDecider.java
@@ -65,16 +65,16 @@ public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, Routing
     public Decision canAllocate(ShardRouting shardRouting, RoutingAllocation allocation) {
         final IndexMetadata indexMetadata = allocation.metadata().getIndexSafe(shardRouting.index());
         if (SearchableSnapshotsSettings.isSearchableSnapshotStore(indexMetadata.getSettings())) {
-            EnableAllocationDecider.Allocation enableAllocation = this.enableAllocation;
-            boolean allocateOnRollingRestart = this.allocateOnRollingRestart;
-            if (enableAllocation == EnableAllocationDecider.Allocation.PRIMARIES) {
-                if (allocateOnRollingRestart == false) {
+            EnableAllocationDecider.Allocation enableAllocationCopy = this.enableAllocation;
+            boolean allocateOnRollingRestartCopy = this.allocateOnRollingRestart;
+            if (enableAllocationCopy == EnableAllocationDecider.Allocation.PRIMARIES) {
+                if (allocateOnRollingRestartCopy == false) {
                     return allocation.decision(
                         Decision.NO,
                         NAME,
                         "no allocations of searchable snapshots allowed during rolling restart due to [%s=%s] and [%s=false]",
                         EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey(),
-                        enableAllocation,
+                        enableAllocationCopy,
                         SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART.getKey()
                     );
                 } else {
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/blob/BlobStoreCacheMaintenanceService.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/blob/BlobStoreCacheMaintenanceService.java
index ff6ff96373640..0780b68d1abfc 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/blob/BlobStoreCacheMaintenanceService.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/blob/BlobStoreCacheMaintenanceService.java
@@ -524,8 +524,8 @@ public void onFailure(Exception e) {
                     assert knownSnapshots != null;
                     final Set<String> knownRepositories = existingRepositories;
                     assert knownRepositories != null;
-                    final Instant expirationTime = this.expirationTime;
-                    assert expirationTime != null;
+                    final Instant expirationTimeCopy = this.expirationTime;
+                    assert expirationTimeCopy != null;
 
                     Object[] lastSortValues = null;
                     for (SearchHit searchHit : searchHits) {
@@ -552,7 +552,7 @@ public void onFailure(Exception e) {
                             }
                             if (delete) {
                                 final Instant creationTime = getCreationTime(searchHit);
-                                if (creationTime.isAfter(expirationTime)) {
+                                if (creationTime.isAfter(expirationTimeCopy)) {
                                     logger.trace(
                                         "blob store cache entry with id [{}] was created recently, skipping deletion",
                                         searchHit.getId()
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ByteRange.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ByteRange.java
index e6196874bfe32..8ba31d1304cdb 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ByteRange.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ByteRange.java
@@ -65,8 +65,8 @@ public boolean isSubRangeOf(ByteRange range) {
         return start >= range.start() && end <= range.end();
     }
 
-    public boolean contains(long start, long end) {
-        return start() <= start && end <= end();
+    public boolean contains(long rangeStart, long rangeEnd) {
+        return start() <= rangeStart && rangeEnd <= end();
     }
 
     public ByteRange shift(long delta) {
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/CacheFile.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/CacheFile.java
index a827b8f3d610f..cdffe597fd816 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/CacheFile.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/CacheFile.java
@@ -180,8 +180,8 @@ public long getInitialLength() {
         return tracker.getInitialLength();
     }
 
-    public void acquire(final EvictionListener listener) throws IOException {
-        assert listener != null;
+    public void acquire(final EvictionListener evictionListener) throws IOException {
+        assert evictionListener != null;
 
         ensureOpen();
         boolean success = false;
@@ -194,8 +194,8 @@ public void acquire(final EvictionListener listener) throws IOException {
                         channelRef = new FileChannelReference(fileExists ? OPEN_OPTIONS : CREATE_OPTIONS);
                         fileExists = true;
                     }
-                    final boolean added = listeners.add(listener);
-                    assert added : "listener already exists " + listener;
+                    final boolean added = listeners.add(evictionListener);
+                    assert added : "listener already exists " + evictionListener;
                 }
                 success = true;
             } finally {
@@ -210,14 +210,14 @@ public void acquire(final EvictionListener listener) throws IOException {
         assert invariant();
     }
 
-    public void release(final EvictionListener listener) {
-        assert listener != null;
+    public void release(final EvictionListener evictionListener) {
+        assert evictionListener != null;
 
         boolean success = false;
         try {
             synchronized (listeners) {
-                final boolean removed = listeners.remove(Objects.requireNonNull(listener));
-                assert removed : "listener does not exist " + listener;
+                final boolean removed = listeners.remove(Objects.requireNonNull(evictionListener));
+                assert removed : "listener does not exist " + evictionListener;
                 if (removed == false) {
                     throw new IllegalStateException("Cannot remove an unknown listener");
                 }
@@ -251,15 +251,15 @@ private void decrementRefCount() {
 
     private boolean assertRefCounted(boolean isReleased) {
         final boolean isEvicted = evicted.get();
-        final boolean fileExists = Files.exists(file);
-        assert isReleased == false || (isEvicted && fileExists == false)
+        final boolean fileDoesExist = Files.exists(file);
+        assert isReleased == false || (isEvicted && fileDoesExist == false)
             : "fully released cache file should be deleted from disk but got ["
                 + "released="
                 + isReleased
                 + ", evicted="
                 + isEvicted
                 + ", file exists="
-                + fileExists
+                + fileDoesExist
                 + ']';
         return true;
     }
@@ -274,7 +274,7 @@ public void startEviction() {
                 evictionListeners = new HashSet<>(listeners);
             }
             decrementRefCount();
-            evictionListeners.forEach(listener -> listener.onEviction(this));
+            evictionListeners.forEach(eachListener -> eachListener.onEviction(this));
         }
         assert invariant();
     }
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ProgressListenableActionFuture.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ProgressListenableActionFuture.java
index 225b72192c003..a0ae32404d867 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ProgressListenableActionFuture.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/common/ProgressListenableActionFuture.java
@@ -65,30 +65,30 @@ private boolean invariant() {
      * (inclusive) to {@code progress} (exclusive) is available. Calling this method potentially triggers the execution of one or
      * more listeners that are waiting for the progress to reach a value lower than the one just updated.
      *
-     * @param progress the new progress value
+     * @param progressValue the new progress value
      */
-    public void onProgress(final long progress) {
+    public void onProgress(final long progressValue) {
         ensureNotCompleted();
 
-        if (progress <= start) {
-            assert false : progress + " <= " + start;
+        if (progressValue <= start) {
+            assert false : progressValue + " <= " + start;
             throw new IllegalArgumentException("Cannot update progress with a value less than [start=" + start + ']');
         }
-        if (end < progress) {
-            assert false : end + " < " + progress;
+        if (end < progressValue) {
+            assert false : end + " < " + progressValue;
             throw new IllegalArgumentException("Cannot update progress with a value greater than [end=" + end + ']');
         }
 
         List<ActionListener<Long>> listenersToExecute = null;
         synchronized (this) {
-            assert this.progress < progress : this.progress + " < " + progress;
-            this.progress = progress;
+            assert this.progress < progressValue : this.progress + " < " + progressValue;
+            this.progress = progressValue;
 
-            final List<Tuple<Long, ActionListener<Long>>> listeners = this.listeners;
-            if (listeners != null) {
+            final List<Tuple<Long, ActionListener<Long>>> listenersCopy = this.listeners;
+            if (listenersCopy != null) {
                 List<Tuple<Long, ActionListener<Long>>> listenersToKeep = null;
-                for (Tuple<Long, ActionListener<Long>> listener : listeners) {
-                    if (progress < listener.v1()) {
+                for (Tuple<Long, ActionListener<Long>> listener : listenersCopy) {
+                    if (progressValue < listener.v1()) {
                         if (listenersToKeep == null) {
                             listenersToKeep = new ArrayList<>();
                         }
@@ -104,7 +104,7 @@ public void onProgress(final long progress) {
             }
         }
         if (listenersToExecute != null) {
-            listenersToExecute.forEach(listener -> executeListener(listener, () -> progress));
+            listenersToExecute.forEach(listener -> executeListener(listener, () -> progressValue));
         }
         assert invariant();
     }
@@ -152,22 +152,22 @@ protected void done(boolean success) {
      */
     public void addListener(ActionListener<Long> listener, long value) {
         boolean executeImmediate = false;
-        final long progress;
+        final long progressValue;
         synchronized (this) {
-            progress = this.progress;
-            if (completed || value <= progress) {
+            progressValue = this.progress;
+            if (completed || value <= progressValue) {
                 executeImmediate = true;
             } else {
-                List<Tuple<Long, ActionListener<Long>>> listeners = this.listeners;
-                if (listeners == null) {
-                    listeners = new ArrayList<>();
+                List<Tuple<Long, ActionListener<Long>>> listenersCopy = this.listeners;
+                if (listenersCopy == null) {
+                    listenersCopy = new ArrayList<>();
                 }
-                listeners.add(Tuple.tuple(value, listener));
-                this.listeners = listeners;
+                listenersCopy.add(Tuple.tuple(value, listener));
+                this.listeners = listenersCopy;
             }
         }
         if (executeImmediate) {
-            executeListener(listener, completed ? () -> actionGet(0L) : () -> progress);
+            executeListener(listener, completed ? () -> actionGet(0L) : () -> progressValue);
         }
         assert invariant();
     }
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/shared/FrozenCacheService.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/shared/FrozenCacheService.java
index 96a2e2e487c07..d6c1687a16f1d 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/shared/FrozenCacheService.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/shared/FrozenCacheService.java
@@ -392,13 +392,13 @@ private long getRegionSize(long fileLength, int region) {
     }
 
     public CacheFileRegion get(CacheKey cacheKey, long fileLength, int region) {
-        final long regionSize = getRegionSize(fileLength, region);
+        final long effectiveRegionSize = getRegionSize(fileLength, region);
         try (Releasable ignore = keyedLock.acquire(cacheKey)) {
             final RegionKey regionKey = new RegionKey(cacheKey, region);
             final long now = currentTimeSupplier.getAsLong();
             final Entry<CacheFileRegion> entry = keyMapping.computeIfAbsent(
                 regionKey,
-                key -> new Entry<>(new CacheFileRegion(regionKey, regionSize), now)
+                key -> new Entry<>(new CacheFileRegion(regionKey, effectiveRegionSize), now)
             );
             if (entry.chunk.sharedBytesPos == -1) {
                 // new item
@@ -905,15 +905,15 @@ public StepListener<Integer> populateAndRead(
                 final StepListener<Integer> lis = fileRegion.populateAndRead(
                     subRangeToWrite,
                     subRangeToRead,
-                    (channel, channelPos, relativePos, length) -> {
+                    (channel, channelPos, relativePos, len) -> {
                         assert regionOwners[fileRegion.sharedBytesPos].get() == fileRegion;
-                        assert channelPos >= fileRegion.physicalStartOffset() && channelPos + length <= fileRegion.physicalEndOffset();
-                        return reader.onRangeAvailable(channel, channelPos, relativePos - readOffset, length);
+                        assert channelPos >= fileRegion.physicalStartOffset() && channelPos + len <= fileRegion.physicalEndOffset();
+                        return reader.onRangeAvailable(channel, channelPos, relativePos - readOffset, len);
                     },
-                    (channel, channelPos, relativePos, length, progressUpdater) -> {
+                    (channel, channelPos, relativePos, len, progressUpdater) -> {
                         assert regionOwners[fileRegion.sharedBytesPos].get() == fileRegion;
-                        assert channelPos >= fileRegion.physicalStartOffset() && channelPos + length <= fileRegion.physicalEndOffset();
-                        writer.fillCacheRange(channel, channelPos, relativePos - writeOffset, length, progressUpdater);
+                        assert channelPos >= fileRegion.physicalStartOffset() && channelPos + len <= fileRegion.physicalEndOffset();
+                        writer.fillCacheRange(channel, channelPos, relativePos - writeOffset, len, progressUpdater);
                     },
                     executor
                 );
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/SearchableSnapshotDirectory.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/SearchableSnapshotDirectory.java
index 8e96bb0c82c03..878d259490a1e 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/SearchableSnapshotDirectory.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/SearchableSnapshotDirectory.java
@@ -204,18 +204,19 @@ protected final boolean assertCurrentThreadMayLoadSnapshot() {
     }
 
     /**
-     * Loads the snapshot if and only if it the snapshot is not loaded yet.
+     * Loads the snapshot if and only if the snapshot is not loaded yet.
      *
      * @return true if the snapshot was loaded by executing this method, false otherwise
      */
-    public boolean loadSnapshot(RecoveryState recoveryState, ActionListener<Void> preWarmListener) {
-        assert recoveryState != null;
-        assert recoveryState instanceof SearchableSnapshotRecoveryState;
-        assert recoveryState.getRecoverySource().getType() == RecoverySource.Type.SNAPSHOT
-            || recoveryState.getRecoverySource().getType() == RecoverySource.Type.PEER : recoveryState.getRecoverySource().getType();
+    public boolean loadSnapshot(RecoveryState snapshotRecoveryState, ActionListener<Void> preWarmListener) {
+        assert snapshotRecoveryState != null;
+        assert snapshotRecoveryState instanceof SearchableSnapshotRecoveryState;
+        assert snapshotRecoveryState.getRecoverySource().getType() == RecoverySource.Type.SNAPSHOT
+            || snapshotRecoveryState.getRecoverySource().getType() == RecoverySource.Type.PEER
+            : snapshotRecoveryState.getRecoverySource().getType();
         assert assertCurrentThreadMayLoadSnapshot();
         // noinspection ConstantConditions in case assertions are disabled
-        if (recoveryState instanceof SearchableSnapshotRecoveryState == false) {
+        if (snapshotRecoveryState instanceof SearchableSnapshotRecoveryState == false) {
             throw new IllegalArgumentException("A SearchableSnapshotRecoveryState instance was expected");
         }
         boolean alreadyLoaded = this.loaded;
@@ -228,7 +229,7 @@ public boolean loadSnapshot(RecoveryState recoveryState, ActionListener<Void> pr
                     this.loaded = true;
                     cleanExistingRegularShardFiles();
                     waitForPendingEvictions();
-                    this.recoveryState = (SearchableSnapshotRecoveryState) recoveryState;
+                    this.recoveryState = (SearchableSnapshotRecoveryState) snapshotRecoveryState;
                     prewarmCache(preWarmListener);
                 }
             }
diff --git a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/input/BaseSearchableSnapshotIndexInput.java b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/input/BaseSearchableSnapshotIndexInput.java
index 4777699fcf692..3ad9cf7834823 100644
--- a/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/input/BaseSearchableSnapshotIndexInput.java
+++ b/x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/store/input/BaseSearchableSnapshotIndexInput.java
@@ -155,8 +155,8 @@ private boolean maybeReadChecksumFromFileInfo(ByteBuffer b) throws IOException {
         return success;
     }
 
-    protected ByteRange rangeToReadFromBlobCache(long position, int length) {
-        final long end = position + length;
+    protected ByteRange rangeToReadFromBlobCache(long position, int readLength) {
+        final long end = position + readLength;
         if (headerBlobCacheByteRange.contains(position, end)) {
             return headerBlobCacheByteRange;
         } else if (footerBlobCacheByteRange.contains(position, end)) {
@@ -170,23 +170,23 @@ protected ByteRange rangeToReadFromBlobCache(long position, int length) {
      * spans multiple blobs then this stream will request them in turn.
      *
      * @param position The start of the range of bytes to read, relative to the start of the corresponding Lucene file.
-     * @param length The number of bytes to read
+     * @param readLength The number of bytes to read
      */
-    protected InputStream openInputStreamFromBlobStore(final long position, final long length) throws IOException {
+    protected InputStream openInputStreamFromBlobStore(final long position, final long readLength) throws IOException {
         assert assertCurrentThreadMayAccessBlobStore();
         if (fileInfo.numberOfParts() == 1L) {
-            assert position + length <= fileInfo.partBytes(0)
-                : "cannot read [" + position + "-" + (position + length) + "] from [" + fileInfo + "]";
-            stats.addBlobStoreBytesRequested(length);
-            return blobContainer.readBlob(fileInfo.partName(0), position, length);
+            assert position + readLength <= fileInfo.partBytes(0)
+                : "cannot read [" + position + "-" + (position + readLength) + "] from [" + fileInfo + "]";
+            stats.addBlobStoreBytesRequested(readLength);
+            return blobContainer.readBlob(fileInfo.partName(0), position, readLength);
         } else {
             final int startPart = getPartNumberForPosition(position);
-            final int endPart = getPartNumberForPosition(position + length - 1);
+            final int endPart = getPartNumberForPosition(position + readLength - 1);
 
             for (int currentPart = startPart; currentPart <= endPart; currentPart++) {
                 final long startInPart = (currentPart == startPart) ? getRelativePositionInPart(position) : 0L;
                 final long endInPart = (currentPart == endPart)
-                    ? getRelativePositionInPart(position + length - 1) + 1
+                    ? getRelativePositionInPart(position + readLength - 1) + 1
                     : getLengthOfPart(currentPart);
                 stats.addBlobStoreBytesRequested(endInPart - startInPart);
             }
@@ -197,7 +197,7 @@ protected InputStream openSlice(int slice) throws IOException {
                     final int currentPart = startPart + slice;
                     final long startInPart = (currentPart == startPart) ? getRelativePositionInPart(position) : 0L;
                     final long endInPart = (currentPart == endPart)
-                        ? getRelativePositionInPart(position + length - 1) + 1
+                        ? getRelativePositionInPart(position + readLength - 1) + 1
                         : getLengthOfPart(currentPart);
                     return blobContainer.readBlob(fileInfo.partName(currentPart), startInPart, endInPart - startInPart);
                 }
diff --git a/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/IndexPrivilegeTests.java b/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/IndexPrivilegeTests.java
index 8e8904bbc0317..7f74b39032fb3 100644
--- a/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/IndexPrivilegeTests.java
+++ b/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/IndexPrivilegeTests.java
@@ -25,7 +25,7 @@
 
 public class IndexPrivilegeTests extends AbstractPrivilegeTestCase {
 
-    private String jsonDoc = "{ \"name\" : \"elasticsearch\", \"body\": \"foo bar\" }";
+    private final String jsonDoc = "{ \"name\" : \"elasticsearch\", \"body\": \"foo bar\" }";
 
     private static final String ROLES = "all_cluster_role:\n"
         + "  cluster: [ all ]\n"
@@ -749,9 +749,9 @@ private void assertUserExecutes(String user, String action, String index, boolea
                 break;
 
             case "delete":
-                String jsonDoc = "{ \"name\" : \"docToDelete\"}";
-                assertAccessIsAllowed("admin", "PUT", "/" + index + "/foo/docToDelete", jsonDoc);
-                assertAccessIsAllowed("admin", "PUT", "/" + index + "/foo/docToDelete2", jsonDoc);
+                String jsonDocToDelete = "{ \"name\" : \"docToDelete\"}";
+                assertAccessIsAllowed("admin", "PUT", "/" + index + "/foo/docToDelete", jsonDocToDelete);
+                assertAccessIsAllowed("admin", "PUT", "/" + index + "/foo/docToDelete2", jsonDocToDelete);
                 if (userIsAllowed) {
                     assertAccessIsAllowed(user, "DELETE", "/" + index + "/foo/docToDelete");
                 } else {
diff --git a/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/SecurityClearScrollTests.java b/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/SecurityClearScrollTests.java
index 66eb0872f7ac8..b5ed77b7809c5 100644
--- a/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/SecurityClearScrollTests.java
+++ b/x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/integration/SecurityClearScrollTests.java
@@ -100,7 +100,7 @@ public void testThatClearingAllScrollIdsWorks() throws Exception {
             .get();
         assertThat(clearScrollResponse.isSucceeded(), is(true));
 
-        assertThatScrollIdsDoNotExist(scrollIds);
+        assertThatScrollIdsDoNotExist();
     }
 
     public void testThatClearingAllScrollIdsRequirePermissions() throws Exception {
@@ -120,10 +120,10 @@ public void testThatClearingAllScrollIdsRequirePermissions() throws Exception {
         assertThat(clearByIdScrollResponse.isSucceeded(), is(true));
 
         // test with each id, that they do not exist
-        assertThatScrollIdsDoNotExist(scrollIds);
+        assertThatScrollIdsDoNotExist();
     }
 
-    private void assertThatScrollIdsDoNotExist(List<String> scrollIds) {
+    private void assertThatScrollIdsDoNotExist() {
         for (String scrollId : scrollIds) {
             SearchPhaseExecutionException expectedException = expectThrows(
                 SearchPhaseExecutionException.class,
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/common/CartesianPoint.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/common/CartesianPoint.java
index eed96ba9fff16..af1493f816a77 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/common/CartesianPoint.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/common/CartesianPoint.java
@@ -60,6 +60,7 @@ public CartesianPoint resetFromString(String value, final boolean ignoreZValue)
         }
     }
 
+    @SuppressWarnings("HiddenField")
     public CartesianPoint resetFromCoordinates(String value, final boolean ignoreZValue) {
         String[] vals = value.split(",");
         if (vals.length > 3 || vals.length < 2) {
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/CentroidCalculator.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/CentroidCalculator.java
index 03c3eba8af0ff..c00cfdba4d3c1 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/CentroidCalculator.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/CentroidCalculator.java
@@ -276,21 +276,22 @@ private void visitLinearRing(
          *  @param x the x-coordinate of the point
          * @param y the y-coordinate of the point
          * @param weight the associated weight of the coordinate
+         * @param shapeType the associated shape type of the coordinate
          */
-        private void addCoordinate(double x, double y, double weight, DimensionalShapeType dimensionalShapeType) {
+        private void addCoordinate(double x, double y, double weight, DimensionalShapeType shapeType) {
             // x and y can be infinite due to really small areas and rounding problems
             if (Double.isFinite(x) && Double.isFinite(y)) {
-                if (this.dimensionalShapeType == dimensionalShapeType) {
+                if (this.dimensionalShapeType == shapeType) {
                     compSumX.add(x * weight);
                     compSumY.add(y * weight);
                     compSumWeight.add(weight);
-                    this.dimensionalShapeType = dimensionalShapeType;
-                } else if (dimensionalShapeType.compareTo(this.dimensionalShapeType) > 0) {
+                    this.dimensionalShapeType = shapeType;
+                } else if (shapeType.compareTo(this.dimensionalShapeType) > 0) {
                     // reset counters
                     compSumX.reset(x * weight, 0);
                     compSumY.reset(y * weight, 0);
                     compSumWeight.reset(weight, 0);
-                    this.dimensionalShapeType = dimensionalShapeType;
+                    this.dimensionalShapeType = shapeType;
                 }
             }
         }
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Extent.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Extent.java
index 3e530b132d38a..c132659fce944 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Extent.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Extent.java
@@ -49,6 +49,7 @@ class Extent {
         this.posRight = posRight;
     }
 
+    @SuppressWarnings("HiddenField")
     public void reset(int top, int bottom, int negLeft, int negRight, int posLeft, int posRight) {
         this.top = top;
         this.bottom = bottom;
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/GeometryDocValueReader.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/GeometryDocValueReader.java
index 04c9216e484cb..0b95d5ac26669 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/GeometryDocValueReader.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/GeometryDocValueReader.java
@@ -99,11 +99,11 @@ protected double getSumCentroidWeight() throws IOException {
      * Visit the triangle tree with the provided visitor
      */
     public void visit(TriangleTreeReader.Visitor visitor) throws IOException {
-        Extent extent = getExtent();
-        int thisMaxX = extent.maxX();
-        int thisMinX = extent.minX();
-        int thisMaxY = extent.maxY();
-        int thisMinY = extent.minY();
+        Extent geometryExtent = getExtent();
+        int thisMaxX = geometryExtent.maxX();
+        int thisMinX = geometryExtent.minX();
+        int thisMaxY = geometryExtent.maxY();
+        int thisMinY = geometryExtent.minY();
         if (visitor.push(thisMinX, thisMinY, thisMaxX, thisMaxY)) {
             TriangleTreeReader.visit(input, visitor, thisMaxX, thisMaxY);
         }
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Tile2DVisitor.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Tile2DVisitor.java
index 8150e711cd9d4..7e9159234122f 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Tile2DVisitor.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/fielddata/Tile2DVisitor.java
@@ -62,9 +62,9 @@ public void visitTriangle(int aX, int aY, int bX, int bY, int cX, int cY, byte m
         boolean ab = (metadata & 1 << 4) == 1 << 4;
         boolean bc = (metadata & 1 << 5) == 1 << 5;
         boolean ca = (metadata & 1 << 6) == 1 << 6;
-        GeoRelation relation = relateTriangle(aX, aY, ab, bX, bY, bc, cX, cY, ca);
-        if (relation != GeoRelation.QUERY_DISJOINT) {
-            this.relation = relation;
+        GeoRelation geoRelation = relateTriangle(aX, aY, ab, bX, bY, bc, cX, cY, ca);
+        if (geoRelation != GeoRelation.QUERY_DISJOINT) {
+            this.relation = geoRelation;
         }
     }
 
@@ -89,6 +89,7 @@ public boolean push(int maxX, int maxY) {
     }
 
     @Override
+    @SuppressWarnings("HiddenField")
     public boolean push(int minX, int minY, int maxX, int maxY) {
         // exclude north and east boundary intersections with tiles from intersection consideration
         // for consistent tiling definition of shapes on the boundaries of tiles
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/mapper/LatLonShapeDocValuesQuery.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/mapper/LatLonShapeDocValuesQuery.java
index 1a615281ba9ad..893f90f13a178 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/mapper/LatLonShapeDocValuesQuery.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/index/mapper/LatLonShapeDocValuesQuery.java
@@ -49,9 +49,9 @@ class LatLonShapeDocValuesQuery extends Query {
     }
 
     @Override
-    public String toString(String field) {
+    public String toString(String otherField) {
         StringBuilder sb = new StringBuilder();
-        if (this.field.equals(field) == false) {
+        if (this.field.equals(otherField) == false) {
             sb.append(this.field);
             sb.append(':');
             sb.append(relation);
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/InternalGeoLine.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/InternalGeoLine.java
index 0cdc49c8ba84f..f2c8722dd73ae 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/InternalGeoLine.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/InternalGeoLine.java
@@ -94,17 +94,17 @@ protected void doWriteTo(StreamOutput out) throws IOException {
     @Override
     public InternalAggregation reduce(List<InternalAggregation> aggregations, ReduceContext reduceContext) {
         int mergedSize = 0;
-        boolean complete = true;
-        boolean includeSorts = true;
+        boolean reducedComplete = true;
+        boolean reducedIncludeSorts = true;
         List<InternalGeoLine> internalGeoLines = new ArrayList<>(aggregations.size());
         for (InternalAggregation aggregation : aggregations) {
             InternalGeoLine geoLine = (InternalGeoLine) aggregation;
             internalGeoLines.add(geoLine);
             mergedSize += geoLine.line.length;
-            complete &= geoLine.complete;
-            includeSorts &= geoLine.includeSorts;
+            reducedComplete &= geoLine.complete;
+            reducedIncludeSorts &= geoLine.includeSorts;
         }
-        complete &= mergedSize <= size;
+        reducedComplete &= mergedSize <= size;
         int finalSize = Math.min(mergedSize, size);
 
         MergedGeoLines mergedGeoLines = new MergedGeoLines(internalGeoLines, finalSize, sortOrder);
@@ -118,8 +118,8 @@ public InternalAggregation reduce(List<InternalAggregation> aggregations, Reduce
             mergedGeoLines.getFinalPoints(),
             mergedGeoLines.getFinalSortValues(),
             getMetadata(),
-            complete,
-            includeSorts,
+            reducedComplete,
+            reducedIncludeSorts,
             sortOrder,
             size
         );
diff --git a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/bucket/geogrid/BoundedGeoTileGridTiler.java b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/bucket/geogrid/BoundedGeoTileGridTiler.java
index ad085b1512e31..ef649a82abb9f 100644
--- a/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/bucket/geogrid/BoundedGeoTileGridTiler.java
+++ b/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/bucket/geogrid/BoundedGeoTileGridTiler.java
@@ -72,6 +72,7 @@ protected long getMaxCells() {
     }
 
     @Override
+    @SuppressWarnings("HiddenField")
     protected int setValuesForFullyContainedTile(int xTile, int yTile, int zTile, GeoShapeCellValues values, int valuesIndex) {
         // For every level we go down, we half each dimension. The total number of splits is equal to 1 << (levelEnd - levelStart)
         final int splits = 1 << precision - zTile;
@@ -101,9 +102,9 @@ protected int setValuesForFullyContainedTile(int xTile, int yTile, int zTile, Ge
                 }
             }
         } else {
-            final int minX = Math.max(this.minX, xTile * splits);
-            final int maxX = Math.min(this.maxX, xTile * splits + splits);
-            for (int i = minX; i < maxX; i++) {
+            final int _minX = Math.max(this.minX, xTile * splits);
+            final int _maxX = Math.min(this.maxX, xTile * splits + splits);
+            for (int i = _minX; i < _maxX; i++) {
                 for (int j = minY; j < maxY; j++) {
                     assert validTile(i, j, precision);
                     values.add(valuesIndex++, GeoTileUtils.longEncodeTiles(precision, i, j));
diff --git a/x-pack/plugin/text-structure/src/main/java/org/elasticsearch/xpack/textstructure/structurefinder/DelimitedTextStructureFinderFactory.java b/x-pack/plugin/text-structure/src/main/java/org/elasticsearch/xpack/textstructure/structurefinder/DelimitedTextStructureFinderFactory.java
index 1eafa2b67c203..47342d745af1c 100644
--- a/x-pack/plugin/text-structure/src/main/java/org/elasticsearch/xpack/textstructure/structurefinder/DelimitedTextStructureFinderFactory.java
+++ b/x-pack/plugin/text-structure/src/main/java/org/elasticsearch/xpack/textstructure/structurefinder/DelimitedTextStructureFinderFactory.java
@@ -27,13 +27,13 @@ public class DelimitedTextStructureFinderFactory implements TextStructureFinderF
         this.trimFields = trimFields;
     }
 
-    DelimitedTextStructureFinderFactory makeSimilar(Character quote, Boolean trimFields) {
+    DelimitedTextStructureFinderFactory makeSimilar(Character quote, Boolean shouldTrimFields) {
 
         return new DelimitedTextStructureFinderFactory(
             (char) csvPreference.getDelimiterChar(),
             (quote == null) ? csvPreference.getQuoteChar() : quote,
             minFieldsPerRow,
-            (trimFields == null) ? this.trimFields : trimFields
+            (shouldTrimFields == null) ? this.trimFields : shouldTrimFields
         );
     }
 
diff --git a/x-pack/plugin/transform/src/internalClusterTest/java/org/elasticsearch/xpack/transform/checkpoint/TransformCheckpointServiceNodeTests.java b/x-pack/plugin/transform/src/internalClusterTest/java/org/elasticsearch/xpack/transform/checkpoint/TransformCheckpointServiceNodeTests.java
index e7587d2e3e3b5..7c4746989c888 100644
--- a/x-pack/plugin/transform/src/internalClusterTest/java/org/elasticsearch/xpack/transform/checkpoint/TransformCheckpointServiceNodeTests.java
+++ b/x-pack/plugin/transform/src/internalClusterTest/java/org/elasticsearch/xpack/transform/checkpoint/TransformCheckpointServiceNodeTests.java
@@ -95,12 +95,12 @@ private class MockClientForCheckpointing extends NoOpClient {
         void setShardStats(ShardStats[] shardStats) {
             this.shardStats = shardStats;
 
-            Set<String> indices = new HashSet<>();
+            Set<String> indicesSet = new HashSet<>();
             for (ShardStats s : shardStats) {
-                indices.add(s.getShardRouting().getIndexName());
+                indicesSet.add(s.getShardRouting().getIndexName());
             }
 
-            this.indices = indices.toArray(new String[0]);
+            this.indices = indicesSet.toArray(new String[0]);
         }
 
         @SuppressWarnings("unchecked")
diff --git a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/Transform.java b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/Transform.java
index a957d0943a7be..28b8c7c3308ac 100644
--- a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/Transform.java
+++ b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/Transform.java
@@ -229,7 +229,7 @@ protected XPackLicenseState getLicenseState() {
 
     @Override
     public List<RestHandler> getRestHandlers(
-        final Settings settings,
+        final Settings unused,
         final RestController restController,
         final ClusterSettings clusterSettings,
         final IndexScopedSettings indexScopedSettings,
@@ -290,12 +290,12 @@ public List<RestHandler> getRestHandlers(
     }
 
     @Override
-    public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settings) {
+    public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settingsToUse) {
         if (transportClientMode) {
             return emptyList();
         }
 
-        FixedExecutorBuilder indexing = new FixedExecutorBuilder(settings, TASK_THREAD_POOL_NAME, 4, 4, "transform.task_thread_pool");
+        FixedExecutorBuilder indexing = new FixedExecutorBuilder(settingsToUse, TASK_THREAD_POOL_NAME, 4, 4, "transform.task_thread_pool");
 
         return Collections.singletonList(indexing);
     }
diff --git a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/ClientTransformIndexer.java b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/ClientTransformIndexer.java
index 9923e56927aa1..f883d5638f72d 100644
--- a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/ClientTransformIndexer.java
+++ b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/ClientTransformIndexer.java
@@ -72,7 +72,7 @@ class ClientTransformIndexer extends TransformIndexer {
     private final Client client;
     private final AtomicBoolean oldStatsCleanedUp = new AtomicBoolean(false);
 
-    private final AtomicReference<SeqNoPrimaryTermAndIndex> seqNoPrimaryTermAndIndex;
+    private final AtomicReference<SeqNoPrimaryTermAndIndex> seqNoPrimaryTermAndIndexHolder;
     private final ConcurrentHashMap<String, PointInTimeBuilder> namedPits = new ConcurrentHashMap<>();
     private volatile long pitCheckpoint;
     private volatile boolean disablePit = false;
@@ -107,7 +107,7 @@ class ClientTransformIndexer extends TransformIndexer {
             context
         );
         this.client = ExceptionsHelper.requireNonNull(client, "client");
-        this.seqNoPrimaryTermAndIndex = new AtomicReference<>(seqNoPrimaryTermAndIndex);
+        this.seqNoPrimaryTermAndIndexHolder = new AtomicReference<>(seqNoPrimaryTermAndIndex);
 
         // TODO: move into context constructor
         context.setShouldStopAtCheckpoint(shouldStopAtCheckpoint);
@@ -329,7 +329,7 @@ void updateSeqNoPrimaryTermAndIndex(SeqNoPrimaryTermAndIndex expectedValue, SeqN
                 newValue
             )
         );
-        boolean updated = seqNoPrimaryTermAndIndex.compareAndSet(expectedValue, newValue);
+        boolean updated = seqNoPrimaryTermAndIndexHolder.compareAndSet(expectedValue, newValue);
         // This should never happen. We ONLY ever update this value if at initialization or we just finished updating the document
         // famous last words...
         if (updated == false) {
@@ -337,7 +337,7 @@ void updateSeqNoPrimaryTermAndIndex(SeqNoPrimaryTermAndIndex expectedValue, SeqN
                 "[{}] Unexpected change to internal state detected, expected [{}], got [{}]",
                 transformConfig.getId(),
                 expectedValue,
-                seqNoPrimaryTermAndIndex.get()
+                seqNoPrimaryTermAndIndexHolder.get()
             );
             assert updated : "[" + getJobId() + "] unexpected change to seqNoPrimaryTermAndIndex.";
         }
@@ -345,7 +345,7 @@ void updateSeqNoPrimaryTermAndIndex(SeqNoPrimaryTermAndIndex expectedValue, SeqN
 
     @Nullable
     SeqNoPrimaryTermAndIndex getSeqNoPrimaryTermAndIndex() {
-        return seqNoPrimaryTermAndIndex.get();
+        return seqNoPrimaryTermAndIndexHolder.get();
     }
 
     @Override
diff --git a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformIndexer.java b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformIndexer.java
index 8fd98c21cad23..e662c5a39f90f 100644
--- a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformIndexer.java
+++ b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformIndexer.java
@@ -320,8 +320,8 @@ protected void onStart(long now, ActionListener<Boolean> listener) {
             }
         }, listener::onFailure);
 
-        ActionListener<Map<String, String>> fieldMappingsListener = ActionListener.wrap(fieldMappings -> {
-            this.fieldMappings = fieldMappings;
+        ActionListener<Map<String, String>> fieldMappingsListener = ActionListener.wrap(mappings -> {
+            this.fieldMappings = mappings;
             configurationReadyListener.onResponse(null);
         }, listener::onFailure);
 
diff --git a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformTask.java b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformTask.java
index d50c2c0261b10..08f3d172bbbb7 100644
--- a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformTask.java
+++ b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/transforms/TransformTask.java
@@ -181,8 +181,8 @@ public void getCheckpointingInfo(
             listener.onResponse(infoBuilder.build());
         }, listener::onFailure);
 
-        ClientTransformIndexer indexer = getIndexer();
-        if (indexer == null) {
+        ClientTransformIndexer transformIndexer = getIndexer();
+        if (transformIndexer == null) {
             transformsCheckpointService.getCheckpointingInfo(
                 parentTaskClient,
                 transform.getId(),
@@ -193,12 +193,12 @@ public void getCheckpointingInfo(
             );
             return;
         }
-        indexer.getCheckpointProvider()
+        transformIndexer.getCheckpointProvider()
             .getCheckpointingInfo(
-                indexer.getLastCheckpoint(),
-                indexer.getNextCheckpoint(),
-                indexer.getPosition(),
-                indexer.getProgress(),
+                transformIndexer.getLastCheckpoint(),
+                transformIndexer.getNextCheckpoint(),
+                transformIndexer.getPosition(),
+                transformIndexer.getProgress(),
                 checkPointInfoListener
             );
     }
diff --git a/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerStateTests.java b/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerStateTests.java
index be5d4cda2bd15..39a7b239d1cb9 100644
--- a/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerStateTests.java
+++ b/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerStateTests.java
@@ -614,7 +614,7 @@ private MockedTransformIndexer createMockIndexer(
         AtomicReference<IndexerState> state,
         Consumer<String> failureConsumer,
         ThreadPool threadPool,
-        TransformAuditor auditor,
+        TransformAuditor transformAuditor,
         TransformIndexerPosition initialPosition,
         TransformIndexerStats jobStats,
         TransformContext context
@@ -624,7 +624,7 @@ private MockedTransformIndexer createMockIndexer(
         TransformServices transformServices = new TransformServices(
             transformConfigManager,
             mock(TransformCheckpointService.class),
-            auditor,
+            transformAuditor,
             mock(SchedulerEngine.class)
         );
 
diff --git a/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerTests.java b/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerTests.java
index bbe9438286ce6..c0018d26345c1 100644
--- a/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerTests.java
+++ b/x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/TransformIndexerTests.java
@@ -436,7 +436,7 @@ private MockedTransformIndexer createMockIndexer(
         AtomicReference<IndexerState> state,
         Consumer<String> failureConsumer,
         ThreadPool threadPool,
-        TransformAuditor auditor,
+        TransformAuditor transformAuditor,
         TransformIndexerStats jobStats,
         TransformContext context
     ) {
@@ -445,7 +445,7 @@ private MockedTransformIndexer createMockIndexer(
         TransformServices transformServices = new TransformServices(
             transformConfigManager,
             mock(TransformCheckpointService.class),
-            auditor,
+            transformAuditor,
             mock(SchedulerEngine.class)
         );