Remove index version and transport version from main endpoint response

docs/reference/setup/install/check-running.asciidoc

@@ -40,10 +40,8 @@ GET /
     "build_date" : "2016-03-30T09:51:41.449Z",
     "build_snapshot" : false,
     "lucene_version" : "{lucene_version}",
-    "index_version" : "67890",
     "minimum_wire_compatibility_version" : "1.2.3",
-    "minimum_index_compatibility_version" : "1.2.3",
-    "transport_version" : "12345"
+    "minimum_index_compatibility_version" : "1.2.3"
   },
   "tagline" : "You Know, for Search"
 }
@@ -56,6 +54,4 @@ GET /
 // TESTRESPONSE[s/"build_snapshot" : false,/"build_snapshot" : $body.version.build_snapshot,/]
 // TESTRESPONSE[s/"minimum_wire_compatibility_version" : "1.2.3"/"minimum_wire_compatibility_version" : $body.version.minimum_wire_compatibility_version/]
 // TESTRESPONSE[s/"minimum_index_compatibility_version" : "1.2.3"/"minimum_index_compatibility_version" : $body.version.minimum_index_compatibility_version/]
-// TESTRESPONSE[s/"transport_version" : "12345"/"transport_version" : $body.version.transport_version/]
-// TESTRESPONSE[s/"index_version" : "67890"/"index_version" : $body.version.index_version/]
 // So much s/// but at least we test that the layout is close to matching....

modules/rest-root/src/main/java/org/elasticsearch/rest/root/MainResponse.java

@@ -29,8 +29,7 @@ public class MainResponse extends ActionResponse implements ToXContentObject {
 
     private String nodeName;
     private Version version;
-    private IndexVersion indexVersion;
-    private TransportVersion transportVersion;
+    private String luceneVersion;
     private ClusterName clusterName;
     private String clusterUuid;
     private Build build;
@@ -41,26 +40,35 @@ public class MainResponse extends ActionResponse implements ToXContentObject {
         super(in);
         nodeName = in.readString();
         version = Version.readVersion(in);
-        indexVersion = in.getTransportVersion().onOrAfter(TransportVersion.V_8_500_031) ? IndexVersion.readVersion(in) : null;
-        transportVersion = in.getTransportVersion().onOrAfter(TransportVersion.V_8_500_019) ? TransportVersion.readVersion(in) : null;
+
+        // Index version and transport version were briefly included in the main response, but
+        // removed before the 8.9.0 release. Reading code remains here (throwing away the values)
+        // for those versions until the new format has propagated through serverless. Additionally,
+        // the lucene version was previously read by inferring from either Version or IndexVersion.
+        // Now the lucene version is read explicitly.
+        if (in.getTransportVersion().onOrAfter(TransportVersion.V_8_500_037)) {
+            luceneVersion = in.readString();
+        } else {
+            if (in.getTransportVersion().onOrAfter(TransportVersion.V_8_500_031)) {
+                luceneVersion = IndexVersion.readVersion(in).luceneVersion().toString();
+            } else if (version.before(Version.V_8_10_0)) {
+                luceneVersion = IndexVersion.fromId(version.id).luceneVersion().toString();
+            } else {
+                luceneVersion = "unknown";
+            }
+            if (in.getTransportVersion().onOrAfter(TransportVersion.V_8_500_019)) {
+                TransportVersion.readVersion(in);
+            }
+        }
         clusterName = new ClusterName(in);
         clusterUuid = in.readString();
         build = Build.readBuild(in);
     }
 
-    public MainResponse(
-        String nodeName,
-        Version version,
-        IndexVersion indexVersion,
-        TransportVersion transportVersion,
-        ClusterName clusterName,
-        String clusterUuid,
-        Build build
-    ) {
+    public MainResponse(String nodeName, Version version, String luceneVersion, ClusterName clusterName, String clusterUuid, Build build) {
         this.nodeName = nodeName;
         this.version = version;
-        this.indexVersion = indexVersion;
-        this.transportVersion = transportVersion;
+        this.luceneVersion = luceneVersion;
         this.clusterName = clusterName;
         this.clusterUuid = clusterUuid;
         this.build = build;
@@ -74,12 +82,8 @@ public Version getVersion() {
         return version;
     }
 
-    public IndexVersion getIndexVersion() {
-        return indexVersion;
-    }
-
-    public TransportVersion getTransportVersion() {
-        return transportVersion;
+    public String getLuceneVersion() {
+        return luceneVersion;
     }
 
     public ClusterName getClusterName() {
@@ -98,27 +102,27 @@ public Build getBuild() {
     public void writeTo(StreamOutput out) throws IOException {
         out.writeString(nodeName);
         Version.writeVersion(version, out);
-        if (out.getTransportVersion().onOrAfter(TransportVersion.V_8_500_031)) {
-            IndexVersion.writeVersion(indexVersion, out);
-        }
-        if (out.getTransportVersion().onOrAfter(TransportVersion.V_8_500_019)) {
-            TransportVersion.writeVersion(transportVersion, out);
+
+        // Index version and transport version were briefly included in the main response, but
+        // removed before the 8.9.0 release. Writing code remains here (writing the latest versions)
+        // for those versions until the new format has propagated through serverless. Additionally,
+        // the lucene version was previously inferred from either Version or IndexVersion.
+        // Now the lucene version is written explicitly.
+        if (out.getTransportVersion().onOrAfter(TransportVersion.V_8_500_037)) {
+            out.writeString(luceneVersion);
+        } else {
+            if (out.getTransportVersion().onOrAfter(TransportVersion.V_8_500_031)) {
+                IndexVersion.writeVersion(IndexVersion.current(), out);
+            }
+            if (out.getTransportVersion().onOrAfter(TransportVersion.V_8_500_019)) {
+                TransportVersion.writeVersion(TransportVersion.current(), out);
+            }
         }
         clusterName.writeTo(out);
         out.writeString(clusterUuid);
         Build.writeBuild(build, out);
     }
 
-    private String getLuceneVersion() {
-        if (indexVersion != null) {
-            return indexVersion.luceneVersion().toString();
-        } else if (version.before(Version.V_8_10_0)) {
-            return IndexVersion.fromId(version.id).luceneVersion().toString();
-        } else {
-            return "unknown";
-        }
-    }
-
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject();
@@ -132,11 +136,9 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             .field("build_hash", build.hash())
             .field("build_date", build.date())
             .field("build_snapshot", build.isSnapshot())
-            .field("lucene_version", getLuceneVersion())
-            .field("index_version", indexVersion != null ? indexVersion.toString() : "unknown")
+            .field("lucene_version", luceneVersion)
             .field("minimum_wire_compatibility_version", version.minimumCompatibilityVersion().toString())
             .field("minimum_index_compatibility_version", version.minimumIndexCompatibilityVersion().toString())
-            .field("transport_version", transportVersion != null ? transportVersion.toString() : "unknown")
             .endObject();
         builder.field("tagline", "You Know, for Search");
         builder.endObject();
@@ -170,16 +172,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             response.version = Version.fromString(
                 ((String) value.get("number")).replace("-SNAPSHOT", "").replaceFirst("-(alpha\\d+|beta\\d+|rc\\d+)", "")
             );
-
-            String indexVersion = (String) value.get("index_version");
-            response.indexVersion = indexVersion != null && indexVersion.equals("unknown") == false
-                ? IndexVersion.fromId(Integer.parseInt(indexVersion))
-                : null;
-
-            String transportVersion = (String) value.get("transport_version");
-            response.transportVersion = transportVersion != null && transportVersion.equals("unknown") == false
-                ? TransportVersion.fromString(transportVersion)
-                : null;
+            response.luceneVersion = ((String) value.get("lucene_version"));
         }, (parser, context) -> parser.map(), new ParseField("version"));
     }
 
@@ -198,16 +191,15 @@ public boolean equals(Object o) {
         MainResponse other = (MainResponse) o;
         return Objects.equals(nodeName, other.nodeName)
             && Objects.equals(version, other.version)
-            && Objects.equals(indexVersion, other.indexVersion)
-            && Objects.equals(transportVersion, other.transportVersion)
+            && Objects.equals(luceneVersion, other.luceneVersion)
             && Objects.equals(clusterUuid, other.clusterUuid)
             && Objects.equals(build, other.build)
             && Objects.equals(clusterName, other.clusterName);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(nodeName, version, indexVersion, transportVersion, clusterUuid, build, clusterName);
+        return Objects.hash(nodeName, version, luceneVersion, clusterUuid, build, clusterName);
     }
 
     @Override
@@ -218,10 +210,8 @@ public String toString() {
             + '\''
             + ", version="
             + version
-            + ", indexVersion="
-            + indexVersion
-            + ", transportVersion="
-            + transportVersion
+            + ", luceneVersion="
+            + luceneVersion
             + ", clusterName="
             + clusterName
             + ", clusterUuid='"

modules/rest-root/src/main/java/org/elasticsearch/rest/root/TransportMainAction.java

@@ -9,7 +9,6 @@
 package org.elasticsearch.rest.root;
 
 import org.elasticsearch.Build;
-import org.elasticsearch.TransportVersion;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
@@ -47,8 +46,7 @@ protected void doExecute(Task task, MainRequest request, ActionListener<MainResp
             new MainResponse(
                 nodeName,
                 Version.CURRENT,
-                IndexVersion.current(),
-                TransportVersion.current(),
+                IndexVersion.current().luceneVersion().toString(),
                 clusterState.getClusterName(),
                 clusterState.metadata().clusterUUID(),
                 Build.current()

modules/rest-root/src/test/java/org/elasticsearch/rest/root/MainResponseTests.java

@@ -40,7 +40,7 @@ protected MainResponse createTestInstance() {
         IndexVersion indexVersion = IndexVersionUtils.randomVersion();
         TransportVersion transportVersion = TransportVersionUtils.randomVersion();
         Build build = new Build(Build.Type.UNKNOWN, randomAlphaOfLength(8), date, randomBoolean(), version.toString());
-        return new MainResponse(nodeName, version, indexVersion, transportVersion, clusterName, clusterUuid, build);
+        return new MainResponse(nodeName, version, indexVersion.luceneVersion().toString(), clusterName, clusterUuid, build);
     }
 
     @Override
@@ -59,12 +59,10 @@ public void testToXContent() throws IOException {
         Build build = new Build(current.type(), current.hash(), current.date(), current.isSnapshot(), current.qualifiedVersion());
         Version version = Version.CURRENT;
         IndexVersion indexVersion = IndexVersion.current();
-        TransportVersion transportVersion = TransportVersion.current();
         MainResponse response = new MainResponse(
             "nodeName",
             version,
-            indexVersion,
-            transportVersion,
+            indexVersion.luceneVersion().toString(),
             new ClusterName("clusterName"),
             clusterUUID,
             build
@@ -87,10 +85,8 @@ public void testToXContent() throws IOException {
                                 "build_date": "%s",
                                 "build_snapshot": %s,
                                 "lucene_version": "%s",
-                                "index_version": "%s",
                                 "minimum_wire_compatibility_version": "%s",
-                                "minimum_index_compatibility_version": "%s",
-                                "transport_version": "%s"
+                                "minimum_index_compatibility_version": "%s"
                             },
                             "tagline": "You Know, for Search"
                         }
@@ -102,10 +98,8 @@ public void testToXContent() throws IOException {
                     current.date(),
                     current.isSnapshot(),
                     indexVersion.luceneVersion().toString(),
-                    indexVersion.toString(),
                     version.minimumCompatibilityVersion().toString(),
-                    version.minimumIndexCompatibilityVersion().toString(),
-                    transportVersion.toString()
+                    version.minimumIndexCompatibilityVersion().toString()
                 )
             ),
             Strings.toString(builder)
@@ -117,21 +111,22 @@ protected MainResponse mutateInstance(MainResponse mutateInstance) {
         String clusterUuid = mutateInstance.getClusterUuid();
         Build build = mutateInstance.getBuild();
         Version version = mutateInstance.getVersion();
-        IndexVersion indexVersion = mutateInstance.getIndexVersion();
-        TransportVersion transportVersion = mutateInstance.getTransportVersion();
+        String luceneVersion = mutateInstance.getLuceneVersion();
         String nodeName = mutateInstance.getNodeName();
         ClusterName clusterName = mutateInstance.getClusterName();
-        switch (randomIntBetween(0, 6)) {
+        switch (randomIntBetween(0, 5)) {
             case 0 -> clusterUuid = clusterUuid + randomAlphaOfLength(5);
             case 1 -> nodeName = nodeName + randomAlphaOfLength(5);
             case 2 ->
                 // toggle the snapshot flag of the original Build parameter
                 build = new Build(Build.Type.UNKNOWN, build.hash(), build.date(), build.isSnapshot() == false, build.qualifiedVersion());
             case 3 -> version = randomValueOtherThan(version, () -> VersionUtils.randomVersion(random()));
             case 4 -> clusterName = new ClusterName(clusterName + randomAlphaOfLength(5));
-            case 5 -> transportVersion = randomValueOtherThan(transportVersion, () -> TransportVersionUtils.randomVersion(random()));
-            case 6 -> indexVersion = randomValueOtherThan(indexVersion, () -> IndexVersionUtils.randomVersion(random()));
+            case 5 -> luceneVersion = randomValueOtherThan(
+                luceneVersion,
+                () -> IndexVersionUtils.randomVersion(random()).luceneVersion().toString()
+            );
         }
-        return new MainResponse(nodeName, version, indexVersion, transportVersion, clusterName, clusterUuid, build);
+        return new MainResponse(nodeName, version, luceneVersion, clusterName, clusterUuid, build);
     }
 }

modules/rest-root/src/test/java/org/elasticsearch/rest/root/RestMainActionTests.java

@@ -37,14 +37,12 @@ public void testHeadResponse() throws Exception {
         final String clusterUUID = randomAlphaOfLengthBetween(10, 20);
         final Version version = Version.CURRENT;
         final IndexVersion indexVersion = IndexVersion.current();
-        final TransportVersion transportVersion = TransportVersion.current();
         final Build build = Build.current();
 
         final MainResponse mainResponse = new MainResponse(
             nodeName,
             version,
-            indexVersion,
-            transportVersion,
+            indexVersion.luceneVersion().toString(),
             clusterName,
             clusterUUID,
             build
@@ -78,8 +76,7 @@ public void testGetResponse() throws Exception {
         final MainResponse mainResponse = new MainResponse(
             nodeName,
             version,
-            indexVersion,
-            transportVersion,
+            indexVersion.luceneVersion().toString(),
             clusterName,
             clusterUUID,
             build

qa/verify-version-constants/src/test/java/org/elasticsearch/qa/verify_version_constants/VerifyVersionConstantsIT.java

@@ -8,6 +8,7 @@
 
 package org.elasticsearch.qa.verify_version_constants;
 
+import org.apache.lucene.tests.util.LuceneTestCase;
 import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
@@ -24,6 +25,7 @@
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.Matchers.lessThan;
 
+@LuceneTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/97736")
 public class VerifyVersionConstantsIT extends ESRestTestCase {
 
     public void testLuceneVersionConstant() throws IOException, ParseException {

server/src/main/java/org/elasticsearch/TransportVersion.java

@@ -156,12 +156,12 @@ private static TransportVersion registerTransportVersion(int id, String uniqueId
     public static final TransportVersion V_8_500_033 = registerTransportVersion(8_500_033, "193ab7c4-a751-4cbd-a66a-2d7d56ccbc10");
     public static final TransportVersion V_8_500_034 = registerTransportVersion(8_500_034, "16871c8b-88ba-4432-980a-10fd9ecad2dc");
     public static final TransportVersion V_8_500_035 = registerTransportVersion(8_500_035, "664dd6ce-3487-4fbd-81a9-af778b28be45");
-
     // Introduced for stateless plugin
     public static final TransportVersion V_8_500_036 = registerTransportVersion(8_500_036, "3343c64f-d7ac-4f02-9262-3e1acfc56f89");
+    public static final TransportVersion V_8_500_037 = registerTransportVersion(8_500_037, "d76a4f22-8878-43e0-acfa-15e452195fa7");
 
     private static class CurrentHolder {
-        private static final TransportVersion CURRENT = findCurrent(V_8_500_036);
+        private static final TransportVersion CURRENT = findCurrent(V_8_500_037);
 
         // finds the pluggable current version, or uses the given fallback
         private static TransportVersion findCurrent(TransportVersion fallback) {

x-pack/plugin/sql/jdbc/src/test/java/org/elasticsearch/xpack/sql/jdbc/WebServerTestCase.java

@@ -8,7 +8,6 @@
 package org.elasticsearch.xpack.sql.jdbc;
 
 import org.elasticsearch.Build;
-import org.elasticsearch.TransportVersion;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.ClusterName;
 import org.elasticsearch.index.IndexVersion;
@@ -54,8 +53,7 @@ MainResponse createMainResponse(Version version) {
         final String date = new Date(randomNonNegativeLong()).toString();
         Build build = new Build(Build.Type.UNKNOWN, randomAlphaOfLength(8), date, randomBoolean(), version.toString());
         IndexVersion indexVersion = IndexVersion.current();
-        TransportVersion transportVersion = TransportVersion.current();
-        return new MainResponse(nodeName, version, indexVersion, transportVersion, clusterName, clusterUuid, build);
+        return new MainResponse(nodeName, version, indexVersion.luceneVersion().toString(), clusterName, clusterUuid, build);
     }
 
     String webServerAddress() {