Harden detection of HTTP/3 support by ensuring Quic native libraries are available for the target platform

CHANGELOG.md

@@ -31,6 +31,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Update RemoteClusterStateCleanupManager to performed batched deletions of stale ClusterMetadataManifests and address deletion timeout issues ([#20566](https://github.com/opensearch-project/OpenSearch/pull/20566))
 - Fix the regression of terms agg optimization at high cardinality ([#20623](https://github.com/opensearch-project/OpenSearch/pull/20623))
 - Support Docker distribution builds for ppc64le, arm64 and s390x ([#20678](https://github.com/opensearch-project/OpenSearch/pull/20678))
+- Harden detection of HTTP/3 support by ensuring Quic native libraries are available for the target platform ([#20680](https://github.com/opensearch-project/OpenSearch/pull/20680))
 
 ### Dependencies
 - Bump shadow-gradle-plugin from 8.3.9 to 9.3.1 ([#20569](https://github.com/opensearch-project/OpenSearch/pull/20569))

libs/netty4/src/main/java/org/opensearch/http/netty4/http3/Http3Utils.java

@@ -8,6 +8,8 @@
 
 package org.opensearch.http.netty4.http3;
 
+import io.netty.handler.codec.quic.Quic;
+
 /**
  * Adapted from reactor.netty.http.internal.Http3 class
  */
@@ -22,7 +24,10 @@ public final class Http3Utils {
         } catch (Throwable t) {
             http3 = false;
         }
-        isHttp3Available = http3;
+        // Quic codec (which is used by HTTP/3 implementation) is provided by the
+        // native library and may not be available on all platforms (even if HTTP/3
+        // codec is present).
+        isHttp3Available = http3 && Quic.isAvailable();
     }
 
     private Http3Utils() {