Downgrade version to 2.18.0 for ser/de of new ClusterStatsRequest metric params. (#16441)

Signed-off-by: Swetha Guptha <[email protected]>
Co-authored-by: Swetha Guptha <[email protected]>

Author: SwethaGuptha

qa/rolling-upgrade/src/test/java/org/opensearch/upgrades/ClusterStatsIT.java

@@ -26,8 +26,8 @@ public class ClusterStatsIT extends AbstractRollingTestCase {
     public void testClusterStats() throws IOException {
         Response response = client().performRequest(new Request("GET", "/_cluster/stats"));
         validateClusterStatsWithFilterResponse(response, nodeStatsMetrics, indicesStatsMetrics);
-        if (AbstractRollingTestCase.UPGRADE_FROM_VERSION.onOrAfter(Version.V_3_0_0) || (
-            CLUSTER_TYPE == ClusterType.UPGRADED && Version.CURRENT.onOrAfter(Version.V_3_0_0))) {
+        if (AbstractRollingTestCase.UPGRADE_FROM_VERSION.onOrAfter(Version.V_2_18_0) || (
+            CLUSTER_TYPE == ClusterType.UPGRADED && Version.CURRENT.onOrAfter(Version.V_2_18_0))) {
             response = client().performRequest(new Request("GET", "/_cluster/stats/os/nodes/_all"));
             validateClusterStatsWithFilterResponse(response, List.of("os"), Collections.emptyList());
             response = client().performRequest(new Request("GET", "/_cluster/stats/indices/mappings/nodes/_all"));

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

@@ -59,7 +59,7 @@ public ClusterStatsRequest(StreamInput in) throws IOException {
         if (in.getVersion().onOrAfter(Version.V_2_16_0)) {
             useAggregatedNodeLevelResponses = in.readOptionalBoolean();
         }
-        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_2_18_0)) {
             computeAllMetrics = in.readOptionalBoolean();
             final long longMetricsFlags = in.readLong();
             for (Metric metric : Metric.values()) {
@@ -135,7 +135,7 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(Version.V_2_16_0)) {
             out.writeOptionalBoolean(useAggregatedNodeLevelResponses);
         }
-        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_2_18_0)) {
             out.writeOptionalBoolean(computeAllMetrics);
             long longMetricFlags = 0;
             for (Metric metric : requestedMetrics) {
@@ -154,7 +154,7 @@ public void writeTo(StreamOutput out) throws IOException {
      * An enumeration of the "core" sections of metrics that may be requested
      * from the cluster stats endpoint.
      */
-    @PublicApi(since = "3.0.0")
+    @PublicApi(since = "2.18.0")
     public enum Metric {
         OS("os", 0),
         JVM("jvm", 1),
@@ -192,7 +192,7 @@ public int getIndex() {
      *
      * When no value is provided for param index_metric, default filter is set to _all.
      */
-    @PublicApi(since = "3.0.0")
+    @PublicApi(since = "2.18.0")
     public enum IndexMetric {
         // Metrics computed from ShardStats
         SHARDS("shards", 0),