diff --git a/common/src/main/java/org/opensearch/ml/common/connector/ConnectorAction.java b/common/src/main/java/org/opensearch/ml/common/connector/ConnectorAction.java
index b62337d49f..4a7555d69b 100644
--- a/common/src/main/java/org/opensearch/ml/common/connector/ConnectorAction.java
+++ b/common/src/main/java/org/opensearch/ml/common/connector/ConnectorAction.java
@@ -208,7 +208,7 @@ public static boolean isValidActionInModelPrediction(ActionType actionType) {
 
         public static boolean isValidAction(String action) {
             try {
-                ActionType.valueOf(action.toUpperCase());
+                ActionType.valueOf(action.toUpperCase(Locale.ROOT));
                 return true;
             } catch (IllegalArgumentException e) {
                 return false;
diff --git a/common/src/main/java/org/opensearch/ml/common/input/parameter/clustering/RCFSummarizeParams.java b/common/src/main/java/org/opensearch/ml/common/input/parameter/clustering/RCFSummarizeParams.java
index 3956514b47..68ce2eec78 100644
--- a/common/src/main/java/org/opensearch/ml/common/input/parameter/clustering/RCFSummarizeParams.java
+++ b/common/src/main/java/org/opensearch/ml/common/input/parameter/clustering/RCFSummarizeParams.java
@@ -8,6 +8,7 @@
 import static org.opensearch.core.xcontent.XContentParserUtils.ensureExpectedToken;
 
 import java.io.IOException;
+import java.util.Locale;
 
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.io.stream.StreamInput;
@@ -97,7 +98,7 @@ public static MLAlgoParams parse(XContentParser parser) throws IOException {
                     parallel = parser.booleanValue();
                     break;
                 case DISTANCE_TYPE_FIELD:
-                    distanceType = DistanceType.from(parser.text().toUpperCase());
+                    distanceType = DistanceType.from(parser.text().toUpperCase(Locale.ROOT));
                     break;
                 default:
                     parser.skipChildren();
diff --git a/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/MLAgentExecutor.java b/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/MLAgentExecutor.java
index ec5031b595..73876990ed 100644
--- a/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/MLAgentExecutor.java
+++ b/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/MLAgentExecutor.java
@@ -13,6 +13,7 @@
 import java.security.PrivilegedExceptionAction;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import org.opensearch.ResourceNotFoundException;
@@ -281,7 +282,7 @@ private ActionListener<Object> createAgentActionListener(
 
     @VisibleForTesting
     protected MLAgentRunner getAgentRunner(MLAgent mlAgent) {
-        final MLAgentType agentType = MLAgentType.from(mlAgent.getType().toUpperCase());
+        final MLAgentType agentType = MLAgentType.from(mlAgent.getType().toUpperCase(Locale.ROOT));
         switch (agentType) {
             case FLOW:
                 return new MLFlowAgentRunner(client, settings, clusterService, xContentRegistry, toolFactories, memoryFactoryMap);
diff --git a/plugin/src/main/java/org/opensearch/ml/action/batch/TransportBatchIngestionAction.java b/plugin/src/main/java/org/opensearch/ml/action/batch/TransportBatchIngestionAction.java
index 6df22475e9..870e8ce97f 100644
--- a/plugin/src/main/java/org/opensearch/ml/action/batch/TransportBatchIngestionAction.java
+++ b/plugin/src/main/java/org/opensearch/ml/action/batch/TransportBatchIngestionAction.java
@@ -15,6 +15,7 @@
 
 import java.time.Instant;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
@@ -101,7 +102,7 @@ protected void doExecute(Task task, ActionRequest request, ActionListener<MLBatc
                     mlTaskManager.add(mlTask);
                     listener.onResponse(new MLBatchIngestionResponse(taskId, MLTaskType.BATCH_INGEST, MLTaskState.CREATED.name()));
                     String ingestType = (String) mlBatchIngestionInput.getDataSources().get(TYPE);
-                    Ingestable ingestable = MLEngineClassLoader.initInstance(ingestType.toLowerCase(), client, Client.class);
+                    Ingestable ingestable = MLEngineClassLoader.initInstance(ingestType.toLowerCase(Locale.ROOT), client, Client.class);
                     threadPool.executor(INGEST_THREAD_POOL).execute(() -> {
                         executeWithErrorHandling(() -> {
                             double successRate = ingestable.ingest(mlBatchIngestionInput);
@@ -193,7 +194,7 @@ private void validateBatchIngestInput(MLBatchIngestionInput mlBatchIngestionInpu
         if (dataSources.get(TYPE) == null || dataSources.get(SOURCE) == null) {
             throw new IllegalArgumentException("The batch ingest input data source is missing data type or source");
         }
-        if (((String) dataSources.get(TYPE)).toLowerCase() == "s3") {
+        if (((String) dataSources.get(TYPE)).equalsIgnoreCase("s3")) {
             List<String> s3Uris = (List<String>) dataSources.get(SOURCE);
             if (s3Uris == null || s3Uris.isEmpty()) {
                 throw new IllegalArgumentException("The batch ingest input s3Uris is empty");
diff --git a/plugin/src/main/java/org/opensearch/ml/rest/RestMLPredictionAction.java b/plugin/src/main/java/org/opensearch/ml/rest/RestMLPredictionAction.java
index 68c0146ab2..a8a8ba8903 100644
--- a/plugin/src/main/java/org/opensearch/ml/rest/RestMLPredictionAction.java
+++ b/plugin/src/main/java/org/opensearch/ml/rest/RestMLPredictionAction.java
@@ -130,7 +130,8 @@ MLPredictionTaskRequest getRequest(String modelId, String algorithm, RestRequest
         ActionType actionType = ActionType.from(getActionTypeFromRestRequest(request));
         if (FunctionName.REMOTE.name().equals(algorithm) && !mlFeatureEnabledSetting.isRemoteInferenceEnabled()) {
             throw new IllegalStateException(REMOTE_INFERENCE_DISABLED_ERR_MSG);
-        } else if (FunctionName.isDLModel(FunctionName.from(algorithm.toUpperCase())) && !mlFeatureEnabledSetting.isLocalModelEnabled()) {
+        } else if (FunctionName.isDLModel(FunctionName.from(algorithm.toUpperCase(Locale.ROOT)))
+            && !mlFeatureEnabledSetting.isLocalModelEnabled()) {
             throw new IllegalStateException(LOCAL_MODEL_DISABLED_ERR_MSG);
         } else if (ActionType.BATCH_PREDICT == actionType && !mlFeatureEnabledSetting.isOfflineBatchInferenceEnabled()) {
             throw new IllegalStateException(BATCH_INFERENCE_DISABLED_ERR_MSG);