Fix log flooding for engine deprecation notice (#2495)

Signed-off-by: Kunal Kotwani <[email protected]>

Author: kotwanikunal

src/main/java/org/opensearch/knn/index/engine/EngineResolver.java

@@ -5,14 +5,19 @@
 
 package org.opensearch.knn.index.engine;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.opensearch.knn.index.mapper.CompressionLevel;
 import org.opensearch.knn.index.mapper.Mode;
 
+import static org.opensearch.knn.index.engine.KNNEngine.DEPRECATED_ENGINES;
+
 /**
  * Figures out what {@link KNNEngine} to use based on configuration details
  */
 public final class EngineResolver {
 
+    private static Logger logger = LogManager.getLogger(EngineResolver.class);
     public static final EngineResolver INSTANCE = new EngineResolver();
 
     private EngineResolver() {}
@@ -32,31 +37,38 @@ public KNNEngine resolveEngine(
     ) {
         // User configuration gets precedence
         if (knnMethodContext != null && knnMethodContext.isEngineConfigured()) {
-            return knnMethodContext.getKnnEngine();
+            return logAndReturnEngine(knnMethodContext.getKnnEngine());
         }
 
         // Faiss is the only engine that supports training, so we default to faiss here for now
         if (requiresTraining) {
-            return KNNEngine.FAISS;
+            return logAndReturnEngine(KNNEngine.FAISS);
         }
 
         Mode mode = knnMethodConfigContext.getMode();
         CompressionLevel compressionLevel = knnMethodConfigContext.getCompressionLevel();
         // If both mode and compression are not specified, we can just default
         if (Mode.isConfigured(mode) == false && CompressionLevel.isConfigured(compressionLevel) == false) {
-            return KNNEngine.DEFAULT;
+            return logAndReturnEngine(KNNEngine.DEFAULT);
         }
 
         // For 1x, we need to default to faiss if mode is provided and use nmslib otherwise
         if (CompressionLevel.isConfigured(compressionLevel) == false || compressionLevel == CompressionLevel.x1) {
-            return mode == Mode.ON_DISK ? KNNEngine.FAISS : KNNEngine.NMSLIB;
+            return logAndReturnEngine(mode == Mode.ON_DISK ? KNNEngine.FAISS : KNNEngine.NMSLIB);
         }
 
         // Lucene is only engine that supports 4x - so we have to default to it here.
         if (compressionLevel == CompressionLevel.x4) {
-            return KNNEngine.LUCENE;
+            return logAndReturnEngine(KNNEngine.LUCENE);
         }
 
-        return KNNEngine.FAISS;
+        return logAndReturnEngine(KNNEngine.FAISS);
+    }
+
+    private KNNEngine logAndReturnEngine(KNNEngine knnEngine) {
+        if (DEPRECATED_ENGINES.contains(knnEngine)) {
+            logger.warn("[Deprecation] {} engine is deprecated and will be removed in a future release.", knnEngine);
+        }
+        return knnEngine;
     }
 }

src/main/java/org/opensearch/knn/index/engine/KNNEngine.java

@@ -6,8 +6,6 @@
 package org.opensearch.knn.index.engine;
 
 import com.google.common.collect.ImmutableSet;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.opensearch.common.ValidationException;
 import org.opensearch.knn.index.SpaceType;
 import org.opensearch.knn.index.engine.faiss.Faiss;
@@ -37,7 +35,7 @@ public enum KNNEngine implements KNNLibrary {
     private static final Set<KNNEngine> CUSTOM_SEGMENT_FILE_ENGINES = ImmutableSet.of(KNNEngine.NMSLIB, KNNEngine.FAISS);
     private static final Set<KNNEngine> ENGINES_SUPPORTING_FILTERS = ImmutableSet.of(KNNEngine.LUCENE, KNNEngine.FAISS);
     public static final Set<KNNEngine> ENGINES_SUPPORTING_RADIAL_SEARCH = ImmutableSet.of(KNNEngine.LUCENE, KNNEngine.FAISS);
-    private static Logger logger = LogManager.getLogger(KNNEngine.class);
+    public static final Set<KNNEngine> DEPRECATED_ENGINES = ImmutableSet.of(KNNEngine.NMSLIB);
 
     private static Map<KNNEngine, Integer> MAX_DIMENSIONS_BY_ENGINE = Map.of(
         KNNEngine.NMSLIB,
@@ -70,9 +68,6 @@ public enum KNNEngine implements KNNLibrary {
      */
     public static KNNEngine getEngine(String name) {
         if (NMSLIB.getName().equalsIgnoreCase(name)) {
-            logger.warn(
-                "[Deprecation] nmslib engine is deprecated and will be removed in a future release. Please use Faiss or Lucene engine instead."
-            );
             return NMSLIB;
         }
 
@@ -95,9 +90,6 @@ public static KNNEngine getEngine(String name) {
      */
     public static KNNEngine getEngineNameFromPath(String path) {
         if (path.endsWith(KNNEngine.NMSLIB.getExtension()) || path.endsWith(KNNEngine.NMSLIB.getCompoundExtension())) {
-            logger.warn(
-                "[Deprecation] nmslib engine is deprecated and will be removed in a future release. Please use Faiss or Lucene engine instead."
-            );
             return KNNEngine.NMSLIB;
         }
 

src/main/java/org/opensearch/knn/index/engine/nmslib/NmslibMethodResolver.java

@@ -5,8 +5,6 @@
 
 package org.opensearch.knn.index.engine.nmslib;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.opensearch.common.ValidationException;
 import org.opensearch.knn.index.SpaceType;
 import org.opensearch.knn.index.engine.AbstractMethodResolver;
@@ -33,7 +31,6 @@
 public class NmslibMethodResolver extends AbstractMethodResolver {
 
     private static final Set<CompressionLevel> SUPPORTED_COMPRESSION_LEVELS = Set.of(CompressionLevel.x1);
-    private static Logger logger = LogManager.getLogger(NmslibMethodResolver.class);
 
     @Override
     public ResolvedMethodContext resolveMethod(
@@ -42,9 +39,6 @@ public ResolvedMethodContext resolveMethod(
         boolean shouldRequireTraining,
         final SpaceType spaceType
     ) {
-        logger.warn(
-            "[Deprecation] nmslib engine is deprecated and will be removed in a future release. Please use Faiss or Lucene engine instead."
-        );
         validateConfig(knnMethodConfigContext, shouldRequireTraining);
         KNNMethodContext resolvedKNNMethodContext = initResolvedKNNMethodContext(
             knnMethodContext,

src/main/java/org/opensearch/knn/jni/JNIService.java

@@ -12,8 +12,6 @@
 package org.opensearch.knn.jni;
 
 import org.apache.commons.lang.ArrayUtils;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.opensearch.common.Nullable;
 import org.opensearch.knn.common.KNNConstants;
 import org.opensearch.knn.index.engine.KNNEngine;
@@ -30,8 +28,6 @@
  */
 public class JNIService {
 
-    private static Logger logger = LogManager.getLogger(JNIService.class);
-
     /**
      * Initialize an index for the native library. Takes in numDocs to
      * allocate the correct amount of memory.
@@ -142,9 +138,6 @@ public static void createIndex(
         KNNEngine knnEngine
     ) {
         if (KNNEngine.NMSLIB == knnEngine) {
-            logger.warn(
-                "[Deprecation] nmslib engine is deprecated and will be removed in a future release. Please use Faiss or Lucene engine instead."
-            );
             NmslibService.createIndex(ids, vectorsAddress, dim, output, parameters);
             return;
         }
@@ -209,9 +202,6 @@ public static long loadIndex(IndexInputWithBuffer readStream, Map<String, Object
                 return FaissService.loadIndexWithStream(readStream);
             }
         } else if (KNNEngine.NMSLIB == knnEngine) {
-            logger.warn(
-                "[Deprecation] nmslib engine is deprecated and will be removed in a future release. Please use Faiss or Lucene engine instead."
-            );
             return NmslibService.loadIndexWithStream(readStream, parameters);
         }