Addressed Michael's comments

Signed-off-by: Peter Alfonsi <petealft@amazon.com>

plugins/cache-ehcache/src/main/java/org/opensearch/cache/store/disk/EhcacheDiskCache.java

@@ -509,15 +509,15 @@ private long getNewValuePairSize(CacheEvent<? extends ICacheKey<K>, ? extends By
         public void onEvent(CacheEvent<? extends ICacheKey<K>, ? extends ByteArrayWrapper> event) {
             switch (event.getType()) {
                 case CREATED:
-                    cacheStatsHolder.incrementEntries(event.getKey().dimensions);
+                    cacheStatsHolder.incrementItems(event.getKey().dimensions);
                     cacheStatsHolder.incrementSizeInBytes(event.getKey().dimensions, getNewValuePairSize(event));
                     assert event.getOldValue() == null;
                     break;
                 case EVICTED:
                     this.removalListener.onRemoval(
                         new RemovalNotification<>(event.getKey(), deserializeValue(event.getOldValue()), RemovalReason.EVICTED)
                     );
-                    cacheStatsHolder.decrementEntries(event.getKey().dimensions);
+                    cacheStatsHolder.decrementItems(event.getKey().dimensions);
                     cacheStatsHolder.decrementSizeInBytes(event.getKey().dimensions, getOldValuePairSize(event));
                     cacheStatsHolder.incrementEvictions(event.getKey().dimensions);
                     assert event.getNewValue() == null;
@@ -526,15 +526,15 @@ public void onEvent(CacheEvent<? extends ICacheKey<K>, ? extends ByteArrayWrappe
                     this.removalListener.onRemoval(
                         new RemovalNotification<>(event.getKey(), deserializeValue(event.getOldValue()), RemovalReason.EXPLICIT)
                     );
-                    cacheStatsHolder.decrementEntries(event.getKey().dimensions);
+                    cacheStatsHolder.decrementItems(event.getKey().dimensions);
                     cacheStatsHolder.decrementSizeInBytes(event.getKey().dimensions, getOldValuePairSize(event));
                     assert event.getNewValue() == null;
                     break;
                 case EXPIRED:
                     this.removalListener.onRemoval(
                         new RemovalNotification<>(event.getKey(), deserializeValue(event.getOldValue()), RemovalReason.INVALIDATED)
                     );
-                    cacheStatsHolder.decrementEntries(event.getKey().dimensions);
+                    cacheStatsHolder.decrementItems(event.getKey().dimensions);
                     cacheStatsHolder.decrementSizeInBytes(event.getKey().dimensions, getOldValuePairSize(event));
                     assert event.getNewValue() == null;
                     break;

plugins/cache-ehcache/src/test/java/org/opensearch/cache/store/disk/EhCacheDiskCacheTests.java

@@ -93,7 +93,7 @@ public void testBasicGetAndPut() throws IOException {
                 String value = ehcacheTest.get(getICacheKey(entry.getKey()));
                 assertEquals(entry.getValue(), value);
             }
-            assertEquals(randomKeys, ehcacheTest.stats().getTotalEntries());
+            assertEquals(randomKeys, ehcacheTest.stats().getTotalItems());
             assertEquals(randomKeys, ehcacheTest.stats().getTotalHits());
             assertEquals(expectedSize, ehcacheTest.stats().getTotalSizeInBytes());
             assertEquals(randomKeys, ehcacheTest.count());
@@ -217,7 +217,7 @@ public void testConcurrentPut() throws Exception {
                 assertEquals(entry.getValue(), value);
             }
             assertEquals(randomKeys, ehcacheTest.count());
-            assertEquals(randomKeys, ehcacheTest.stats().getTotalEntries());
+            assertEquals(randomKeys, ehcacheTest.stats().getTotalItems());
             ehcacheTest.close();
         }
     }
@@ -416,7 +416,7 @@ public String load(ICacheKey<String> key) {
             assertEquals(1, numberOfTimesValueLoaded);
             assertEquals(0, ((EhcacheDiskCache) ehcacheTest).getCompletableFutureMap().size());
             assertEquals(1, ehcacheTest.stats().getTotalMisses());
-            assertEquals(1, ehcacheTest.stats().getTotalEntries());
+            assertEquals(1, ehcacheTest.stats().getTotalItems());
             assertEquals(numberOfRequest - 1, ehcacheTest.stats().getTotalHits());
             assertEquals(1, ehcacheTest.count());
             ehcacheTest.close();

server/src/internalClusterTest/java/org/opensearch/indices/CacheStatsAPIIndicesRequestCacheIT.java

@@ -245,7 +245,7 @@ private static Map<String, Object> getNodeCacheStatsXContentMap(Client client, L
         NodesStatsResponse nodeStatsResponse = client.admin()
             .cluster()
             .prepareNodesStats("data:true")
-            .addMetric(NodesStatsRequest.Metric.SEARCH_CACHE_STATS.metricName())
+            .addMetric(NodesStatsRequest.Metric.CACHE_STATS.metricName())
             .setIndices(statsFlags)
             .get();
         // Can always get the first data node as there's only one in this test suite
@@ -288,7 +288,7 @@ private static void checkCacheStatsAPIResponse(
             assertEquals(expectedStats.getSizeInBytes(), (int) aggregatedStatsResponse.get(ImmutableCacheStats.Fields.SIZE_IN_BYTES));
         }
         if (checkEntries) {
-            assertEquals(expectedStats.getEntries(), (int) aggregatedStatsResponse.get(ImmutableCacheStats.Fields.ENTRIES));
+            assertEquals(expectedStats.getItems(), (int) aggregatedStatsResponse.get(ImmutableCacheStats.Fields.ITEM_COUNT));
         }
     }
 }

server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodesStatsRequest.java

@@ -220,7 +220,7 @@ public enum Metric {
         SEGMENT_REPLICATION_BACKPRESSURE("segment_replication_backpressure"),
         REPOSITORIES("repositories"),
         ADMISSION_CONTROL("admission_control"),
-        SEARCH_CACHE_STATS("caches");
+        CACHE_STATS("caches");
 
         private String metricName;
 

server/src/main/java/org/opensearch/action/admin/cluster/node/stats/TransportNodesStatsAction.java

@@ -129,7 +129,7 @@ protected NodeStats nodeOperation(NodeStatsRequest nodeStatsRequest) {
             NodesStatsRequest.Metric.SEGMENT_REPLICATION_BACKPRESSURE.containedIn(metrics),
             NodesStatsRequest.Metric.REPOSITORIES.containedIn(metrics),
             NodesStatsRequest.Metric.ADMISSION_CONTROL.containedIn(metrics),
-            NodesStatsRequest.Metric.SEARCH_CACHE_STATS.containedIn(metrics)
+            NodesStatsRequest.Metric.CACHE_STATS.containedIn(metrics)
         );
     }
 

server/src/main/java/org/opensearch/action/admin/indices/stats/CommonStatsFlags.java

@@ -43,6 +43,7 @@
 import java.io.IOException;
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.Set;
 
 /**
  * Common Stats Flags for OpenSearch
@@ -167,7 +168,7 @@ public Flag[] getFlags() {
         return flags.toArray(new Flag[0]);
     }
 
-    public EnumSet<CacheType> getIncludeCaches() {
+    public Set<CacheType> getIncludeCaches() {
         return includeCaches;
     }
 

server/src/main/java/org/opensearch/common/cache/CacheType.java

@@ -23,7 +23,7 @@ public enum CacheType {
     INDICES_REQUEST_CACHE("indices.requests.cache", "request_cache");
 
     private final String settingPrefix;
-    private final String value; // The value displayed for this cache type in API responses
+    private final String value; // The value displayed for this cache type in stats API responses
 
     private static final Map<String, CacheType> valuesMap;
     static {

server/src/main/java/org/opensearch/common/cache/stats/CacheStats.java

@@ -20,9 +20,9 @@ public class CacheStats {
     CounterMetric misses;
     CounterMetric evictions;
     CounterMetric sizeInBytes;
-    CounterMetric entries;
+    CounterMetric items;
 
-    public CacheStats(long hits, long misses, long evictions, long sizeInBytes, long entries) {
+    public CacheStats(long hits, long misses, long evictions, long sizeInBytes, long items) {
         this.hits = new CounterMetric();
         this.hits.inc(hits);
         this.misses = new CounterMetric();
@@ -31,8 +31,8 @@ public CacheStats(long hits, long misses, long evictions, long sizeInBytes, long
         this.evictions.inc(evictions);
         this.sizeInBytes = new CounterMetric();
         this.sizeInBytes.inc(sizeInBytes);
-        this.entries = new CounterMetric();
-        this.entries.inc(entries);
+        this.items = new CounterMetric();
+        this.items.inc(items);
     }
 
     public CacheStats() {
@@ -44,33 +44,33 @@ private void internalAdd(long otherHits, long otherMisses, long otherEvictions,
         this.misses.inc(otherMisses);
         this.evictions.inc(otherEvictions);
         this.sizeInBytes.inc(otherSizeInBytes);
-        this.entries.inc(otherEntries);
+        this.items.inc(otherEntries);
     }
 
     public void add(CacheStats other) {
         if (other == null) {
             return;
         }
-        internalAdd(other.getHits(), other.getMisses(), other.getEvictions(), other.getSizeInBytes(), other.getEntries());
+        internalAdd(other.getHits(), other.getMisses(), other.getEvictions(), other.getSizeInBytes(), other.getItems());
     }
 
     public void add(ImmutableCacheStats snapshot) {
         if (snapshot == null) {
             return;
         }
-        internalAdd(snapshot.getHits(), snapshot.getMisses(), snapshot.getEvictions(), snapshot.getSizeInBytes(), snapshot.getEntries());
+        internalAdd(snapshot.getHits(), snapshot.getMisses(), snapshot.getEvictions(), snapshot.getSizeInBytes(), snapshot.getItems());
     }
 
     public void subtract(ImmutableCacheStats other) {
         if (other == null) {
             return;
         }
-        internalAdd(-other.getHits(), -other.getMisses(), -other.getEvictions(), -other.getSizeInBytes(), -other.getEntries());
+        internalAdd(-other.getHits(), -other.getMisses(), -other.getEvictions(), -other.getSizeInBytes(), -other.getItems());
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(hits.count(), misses.count(), evictions.count(), sizeInBytes.count(), entries.count());
+        return Objects.hash(hits.count(), misses.count(), evictions.count(), sizeInBytes.count(), items.count());
     }
 
     public void incrementHits() {
@@ -93,12 +93,12 @@ public void decrementSizeInBytes(long amount) {
         sizeInBytes.dec(amount);
     }
 
-    public void incrementEntries() {
-        entries.inc();
+    public void incrementItems() {
+        items.inc();
     }
 
-    public void decrementEntries() {
-        entries.dec();
+    public void decrementItems() {
+        items.dec();
     }
 
     public long getHits() {
@@ -117,16 +117,16 @@ public long getSizeInBytes() {
         return sizeInBytes.count();
     }
 
-    public long getEntries() {
-        return entries.count();
+    public long getItems() {
+        return items.count();
     }
 
     public void resetSizeAndEntries() {
         sizeInBytes = new CounterMetric();
-        entries = new CounterMetric();
+        items = new CounterMetric();
     }
 
     public ImmutableCacheStats immutableSnapshot() {
-        return new ImmutableCacheStats(hits.count(), misses.count(), evictions.count(), sizeInBytes.count(), entries.count());
+        return new ImmutableCacheStats(hits.count(), misses.count(), evictions.count(), sizeInBytes.count(), items.count());
     }
 }

server/src/main/java/org/opensearch/common/cache/stats/CacheStatsHolder.java

@@ -80,12 +80,12 @@ public void decrementSizeInBytes(List<String> dimensionValues, long amountBytes)
         internalIncrement(dimensionValues, (node) -> node.decrementSizeInBytes(amountBytes), false);
     }
 
-    public void incrementEntries(List<String> dimensionValues) {
-        internalIncrement(dimensionValues, Node::incrementEntries, true);
+    public void incrementItems(List<String> dimensionValues) {
+        internalIncrement(dimensionValues, Node::incrementItems, true);
     }
 
-    public void decrementEntries(List<String> dimensionValues) {
-        internalIncrement(dimensionValues, Node::decrementEntries, false);
+    public void decrementItems(List<String> dimensionValues) {
+        internalIncrement(dimensionValues, Node::decrementItems, false);
     }
 
     /**
@@ -105,7 +105,7 @@ private void resetHelper(Node current) {
 
     public long count() {
         // Include this here so caches don't have to create an entire CacheStats object to run count().
-        return statsRoot.getEntries();
+        return statsRoot.getItems();
     }
 
     private void internalIncrement(List<String> dimensionValues, Consumer<Node> adder, boolean createNodesIfAbsent) {
@@ -255,16 +255,16 @@ void decrementSizeInBytes(long amountBytes) {
             this.stats.decrementSizeInBytes(amountBytes);
         }
 
-        void incrementEntries() {
-            this.stats.incrementEntries();
+        void incrementItems() {
+            this.stats.incrementItems();
         }
 
-        void decrementEntries() {
-            this.stats.decrementEntries();
+        void decrementItems() {
+            this.stats.decrementItems();
         }
 
-        long getEntries() {
-            return this.stats.getEntries();
+        long getItems() {
+            return this.stats.getItems();
         }
 
         ImmutableCacheStats getImmutableStats() {

server/src/main/java/org/opensearch/common/cache/stats/ImmutableCacheStats.java

@@ -30,14 +30,14 @@ public class ImmutableCacheStats implements Writeable, ToXContent {
     private final long misses;
     private final long evictions;
     private final long sizeInBytes;
-    private final long entries;
+    private final long items;
 
-    public ImmutableCacheStats(long hits, long misses, long evictions, long sizeInBytes, long entries) {
+    public ImmutableCacheStats(long hits, long misses, long evictions, long sizeInBytes, long items) {
         this.hits = hits;
         this.misses = misses;
         this.evictions = evictions;
         this.sizeInBytes = sizeInBytes;
-        this.entries = entries;
+        this.items = items;
     }
 
     public ImmutableCacheStats(StreamInput in) throws IOException {
@@ -50,7 +50,7 @@ public static ImmutableCacheStats addSnapshots(ImmutableCacheStats s1, Immutable
             s1.misses + s2.misses,
             s1.evictions + s2.evictions,
             s1.sizeInBytes + s2.sizeInBytes,
-            s1.entries + s2.entries
+            s1.items + s2.items
         );
     }
 
@@ -70,8 +70,8 @@ public long getSizeInBytes() {
         return sizeInBytes;
     }
 
-    public long getEntries() {
-        return entries;
+    public long getItems() {
+        return items;
     }
 
     @Override
@@ -80,7 +80,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(misses);
         out.writeVLong(evictions);
         out.writeVLong(sizeInBytes);
-        out.writeVLong(entries);
+        out.writeVLong(items);
     }
 
     @Override
@@ -96,12 +96,12 @@ public boolean equals(Object o) {
             && (misses == other.misses)
             && (evictions == other.evictions)
             && (sizeInBytes == other.sizeInBytes)
-            && (entries == other.entries);
+            && (items == other.items);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(hits, misses, evictions, sizeInBytes, entries);
+        return Objects.hash(hits, misses, evictions, sizeInBytes, items);
     }
 
     @Override
@@ -111,7 +111,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         builder.field(Fields.EVICTIONS, evictions);
         builder.field(Fields.HIT_COUNT, hits);
         builder.field(Fields.MISS_COUNT, misses);
-        builder.field(Fields.ENTRIES, entries);
+        builder.field(Fields.ITEM_COUNT, items);
         return builder;
     }
 
@@ -124,6 +124,6 @@ public static final class Fields {
         public static final String EVICTIONS = "evictions";
         public static final String HIT_COUNT = "hit_count";
         public static final String MISS_COUNT = "miss_count";
-        public static final String ENTRIES = "entries";
+        public static final String ITEM_COUNT = "item_count";
     }
 }

server/src/main/java/org/opensearch/common/cache/stats/ImmutableCacheStatsHolder.java

@@ -151,8 +151,8 @@ public long getTotalSizeInBytes() {
         return getTotalStats().getSizeInBytes();
     }
 
-    public long getTotalEntries() {
-        return getTotalStats().getEntries();
+    public long getTotalItems() {
+        return getTotalStats().getItems();
     }
 
     public ImmutableCacheStats getStatsForDimensionValues(List<String> dimensionValues) {

server/src/main/java/org/opensearch/common/cache/store/OpenSearchOnHeapCache.java

@@ -81,7 +81,7 @@ public V get(ICacheKey<K> key) {
     @Override
     public void put(ICacheKey<K> key, V value) {
         cache.put(key, value);
-        cacheStatsHolder.incrementEntries(key.dimensions);
+        cacheStatsHolder.incrementItems(key.dimensions);
         cacheStatsHolder.incrementSizeInBytes(key.dimensions, weigher.applyAsLong(key, value));
     }
 
@@ -92,7 +92,7 @@ public V computeIfAbsent(ICacheKey<K> key, LoadAwareCacheLoader<ICacheKey<K>, V>
             cacheStatsHolder.incrementHits(key.dimensions);
         } else {
             cacheStatsHolder.incrementMisses(key.dimensions);
-            cacheStatsHolder.incrementEntries(key.dimensions);
+            cacheStatsHolder.incrementItems(key.dimensions);
             cacheStatsHolder.incrementSizeInBytes(key.dimensions, cache.getWeigher().applyAsLong(key, value));
         }
         return value;
@@ -140,7 +140,7 @@ public ImmutableCacheStatsHolder stats(String[] levels) {
     @Override
     public void onRemoval(RemovalNotification<ICacheKey<K>, V> notification) {
         removalListener.onRemoval(notification);
-        cacheStatsHolder.decrementEntries(notification.getKey().dimensions);
+        cacheStatsHolder.decrementItems(notification.getKey().dimensions);
         cacheStatsHolder.decrementSizeInBytes(
             notification.getKey().dimensions,
             cache.getWeigher().applyAsLong(notification.getKey(), notification.getValue())