[Tiered Caching] Bump versions for serialization in new cache stats API (opensearch-project#13460)

---------

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

Author: peteralfonsi

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

@@ -238,7 +238,7 @@ public NodeStats(StreamInput in) throws IOException {
         } else {
             admissionControlStats = null;
         }
-        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_2_14_0)) {
             nodeCacheStats = in.readOptionalWriteable(NodeCacheStats::new);
         } else {
             nodeCacheStats = null;
@@ -522,7 +522,7 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(Version.V_2_12_0)) {
             out.writeOptionalWriteable(admissionControlStats);
         }
-        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_2_14_0)) {
             out.writeOptionalWriteable(nodeCacheStats);
         }
     }

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

@@ -96,7 +96,7 @@ public CommonStatsFlags(StreamInput in) throws IOException {
         includeUnloadedSegments = in.readBoolean();
         includeAllShardIndexingPressureTrackers = in.readBoolean();
         includeOnlyTopIndexingPressureMetrics = in.readBoolean();
-        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_2_14_0)) {
             includeCaches = in.readEnumSet(CacheType.class);
             levels = in.readStringArray();
         }
@@ -120,7 +120,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeBoolean(includeUnloadedSegments);
         out.writeBoolean(includeAllShardIndexingPressureTrackers);
         out.writeBoolean(includeOnlyTopIndexingPressureMetrics);
-        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_2_14_0)) {
             out.writeEnumSet(includeCaches);
             out.writeStringArrayNullable(levels);
         }

server/src/main/java/org/opensearch/index/cache/request/ShardRequestCache.java

@@ -32,6 +32,7 @@
 
 package org.opensearch.index.cache.request;
 
+import org.apache.lucene.util.Accountable;
 import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.core.common.bytes.BytesReference;
@@ -61,6 +62,7 @@ public void onMiss() {
         missCount.inc();
     }
 
+    // Functions used to increment size by passing in the size directly, Used now, as we use ICacheKey<Key> in the IndicesRequestCache..
     public void onCached(long keyRamBytesUsed, BytesReference value) {
         totalMetric.inc(keyRamBytesUsed + value.ramBytesUsed());
     }
@@ -75,4 +77,22 @@ public void onRemoval(long keyRamBytesUsed, BytesReference value, boolean evicte
         }
         totalMetric.dec(dec);
     }
+
+    // Old functions which increment size by passing in an Accountable. Functional but no longer used.
+    public void onCached(Accountable key, BytesReference value) {
+        totalMetric.inc(key.ramBytesUsed() + value.ramBytesUsed());
+    }
+
+    public void onRemoval(Accountable key, BytesReference value, boolean evicted) {
+        if (evicted) {
+            evictionsMetric.inc();
+        }
+        long dec = 0;
+        if (key != null) {
+            dec += key.ramBytesUsed();
+        }
+        if (value != null) {
+            dec += value.ramBytesUsed();
+        }
+    }
 }