Introduce minimumCompatibilityVersion to BuildVersion (ES-9378)

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

@@ -10,7 +10,7 @@
 package org.elasticsearch;
 
 import org.elasticsearch.common.Strings;
-import org.elasticsearch.core.UpdateForV9;
+import org.elasticsearch.core.UpdateForV10;
 import org.elasticsearch.internal.BuildExtension;
 import org.elasticsearch.plugins.ExtensionLoader;
 
@@ -114,8 +114,7 @@ private static IntFunction<String> lookupFunction(NavigableMap<Integer, List<Ver
                     // this will no longer be the case with ES 10 (which won't know about ES v8.x where we introduced separated versions)
                     // maybe keep the release mapping around in the csv file?
                     // SEP for now
-                    @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA)
-                    // @UpdateForV10(owner = UpdateForV10.Owner.CORE_INFRA)
+                    @UpdateForV10(owner = UpdateForV10.Owner.CORE_INFRA)
                     Version oldVersion = Version.fromId(id);
                     return oldVersion.toString();
                 }

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

@@ -14,8 +14,8 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.core.Assertions;
+import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.core.SuppressForbidden;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.monitor.jvm.JvmInfo;
 import org.elasticsearch.xcontent.ToXContentFragment;
 import org.elasticsearch.xcontent.XContentBuilder;
@@ -240,17 +240,15 @@ public class Version implements VersionId<Version>, ToXContentFragment {
         VERSION_STRINGS = Map.copyOf(builderByString);
     }
 
-    @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA)
-    // Re-enable this assertion once the rest api version is bumped
     private static void assertRestApiVersion() {
-        // assert RestApiVersion.current().major == CURRENT.major && RestApiVersion.previous().major == CURRENT.major - 1
-        // : "RestApiVersion must be upgraded "
-        // + "to reflect major from Version.CURRENT ["
-        // + CURRENT.major
-        // + "]"
-        // + " but is still set to ["
-        // + RestApiVersion.current().major
-        // + "]";
+        assert RestApiVersion.current().major == CURRENT.major && RestApiVersion.previous().major == CURRENT.major - 1
+            : "RestApiVersion must be upgraded "
+                + "to reflect major from Version.CURRENT ["
+                + CURRENT.major
+                + "]"
+                + " but is still set to ["
+                + RestApiVersion.current().major
+                + "]";
     }
 
     public static Version readVersion(StreamInput in) throws IOException {

server/src/main/java/org/elasticsearch/cluster/ClusterState.java

@@ -47,7 +47,6 @@
 import org.elasticsearch.common.xcontent.ChunkedToXContentHelper;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.core.SuppressForbidden;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.index.shard.IndexLongFieldRange;
 import org.elasticsearch.indices.SystemIndexDescriptor;
 import org.elasticsearch.xcontent.ToXContent;
@@ -1039,12 +1038,6 @@ public static ClusterState readFrom(StreamInput in, DiscoveryNode localNode) thr
         return builder.build();
     }
 
-    /**
-     * If the cluster state does not contain transport version information, this is the version
-     * that is inferred for all nodes on version 8.8.0 or above.
-     */
-    @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA)
-    public static final TransportVersion INFERRED_TRANSPORT_VERSION = TransportVersions.V_8_8_0;
     public static final Version VERSION_INTRODUCING_TRANSPORT_VERSIONS = Version.V_8_8_0;
 
     @Override

server/src/main/java/org/elasticsearch/env/BuildVersion.java

@@ -73,6 +73,12 @@ public abstract class BuildVersion implements ToXContentFragment, Writeable {
      */
     public abstract String toNodeMetadata();
 
+    /**
+     * Returns the minimum compatible build version based on the current version.
+     * Ie a node needs to have at least the return version in order to communicate with a node running the current version.
+     */
+    public abstract BuildVersion minimumCompatibilityVersion();
+
     /**
      * Create a {@link BuildVersion} from a version ID number.
      *

server/src/main/java/org/elasticsearch/env/DefaultBuildVersion.java

@@ -73,6 +73,11 @@ public String toNodeMetadata() {
         return Integer.toString(version.id());
     }
 
+    @Override
+    public BuildVersion minimumCompatibilityVersion() {
+        return fromVersionId(version.minimumCompatibilityVersion().id);
+    }
+
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         return builder.value(version.id());

server/src/main/java/org/elasticsearch/env/NodeEnvironment.java

@@ -86,8 +86,6 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -525,7 +523,7 @@ static void checkForIndexCompatibility(Logger logger, DataPath... dataPaths) thr
         logger.info("oldest index version recorded in NodeMetadata {}", metadata.oldestIndexVersion());
 
         if (metadata.oldestIndexVersion().before(IndexVersions.MINIMUM_COMPATIBLE)) {
-            String bestDowngradeVersion = getBestDowngradeVersion(metadata.previousNodeVersion().toString());
+            BuildVersion bestDowngradeVersion = getBestDowngradeVersion(metadata.previousNodeVersion());
             throw new IllegalStateException(
                 "Cannot start this node because it holds metadata for indices with version ["
                     + metadata.oldestIndexVersion().toReleaseVersion()
@@ -1504,28 +1502,17 @@ private static void tryWriteTempFile(Path path) throws IOException {
     /**
      * Get a useful version string to direct a user's downgrade operation
      *
-     * <p>If a user is trying to install 8.0 but has incompatible indices, the user should
-     * downgrade to 7.17.x. We return 7.17.0, unless the user is trying to upgrade from
-     * a 7.17.x release, in which case we return the last installed version.
+     * <p>If a user is trying to install current major N but has incompatible indices, the user should
+     * downgrade to last minor of the previous major (N-1).last. We return (N-1).last, unless the user is trying to upgrade from
+     * a (N-1).last.x release, in which case we return the last installed version.
      * @return Version to downgrade to
      */
     // visible for testing
-    static String getBestDowngradeVersion(String previousNodeVersion) {
-        // this method should only be called in the context of an upgrade to 8.x
-        assert Build.current().version().startsWith("9.") == false;
-        Pattern pattern = Pattern.compile("^7\\.(\\d+)\\.\\d+$");
-        Matcher matcher = pattern.matcher(previousNodeVersion);
-        if (matcher.matches()) {
-            try {
-                int minorVersion = Integer.parseInt(matcher.group(1));
-                if (minorVersion >= 17) {
-                    return previousNodeVersion;
-                }
-            } catch (NumberFormatException e) {
-                // continue and return default
-            }
+    static BuildVersion getBestDowngradeVersion(BuildVersion previousNodeVersion) {
+        if (previousNodeVersion.onOrAfterMinimumCompatible()) {
+            return previousNodeVersion;
         }
-        return "7.17.0";
+        return BuildVersion.current().minimumCompatibilityVersion();
     }
 
 }

server/src/main/java/org/elasticsearch/env/NodeMetadata.java

@@ -10,7 +10,6 @@
 package org.elasticsearch.env;
 
 import org.elasticsearch.Build;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.gateway.MetadataStateFormat;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.index.IndexVersions;
@@ -158,12 +157,11 @@ public void setOldestIndexVersion(int oldestIndexVersion) {
             this.oldestIndexVersion = IndexVersion.fromId(oldestIndexVersion);
         }
 
-        @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA) // version is required in the node metadata from v9 onwards
         public NodeMetadata build() {
             final IndexVersion oldestIndexVersion;
 
             if (this.nodeVersion == null) {
-                nodeVersion = BuildVersion.fromVersionId(0);
+                throw new IllegalStateException("Node version is required in node metadata");
             }
             if (this.previousNodeVersion == null) {
                 previousNodeVersion = nodeVersion;

server/src/test/java/org/elasticsearch/env/BuildVersionTests.java

@@ -43,6 +43,16 @@ public void testIsFutureVersion() {
         assertTrue(futureVersion.isFutureVersion());
     }
 
+    public void testMinimumCompatibilityVersion() {
+        BuildVersion minCompatible = BuildVersion.fromVersionId(Version.CURRENT.minimumCompatibilityVersion().id());
+        assertThat(BuildVersion.current().minimumCompatibilityVersion(), equalTo(minCompatible));
+
+        BuildVersion previousCompatible = BuildVersion.fromVersionId(
+            Version.CURRENT.minimumCompatibilityVersion().minimumCompatibilityVersion().id()
+        );
+        assertThat(minCompatible.minimumCompatibilityVersion(), equalTo(previousCompatible));
+    }
+
     public static BuildVersion increment(BuildVersion version) {
         return BuildVersion.fromVersionId(((DefaultBuildVersion) version).version.id() + 1);
     }

server/src/test/java/org/elasticsearch/env/NodeEnvironmentTests.java

@@ -584,7 +584,9 @@ public void testIndexCompatibilityChecks() throws IOException {
                     containsString("it holds metadata for indices with version [" + oldIndexVersion.toReleaseVersion() + "]"),
                     containsString(
                         "Revert this node to version ["
-                            + (previousNodeVersion.major == Version.V_8_0_0.major ? Version.V_7_17_0 : previousNodeVersion)
+                            + (previousNodeVersion.major == Version.CURRENT.major
+                                ? Version.CURRENT.minimumCompatibilityVersion()
+                                : previousNodeVersion)
                             + "]"
                     )
                 )
@@ -638,20 +640,31 @@ public void testSymlinkDataDirectory() throws Exception {
         env.close();
     }
 
-    @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA)
-    @AwaitsFix(bugUrl = "test won't work until we remove and bump minimum index versions")
     public void testGetBestDowngradeVersion() {
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.17.0"), Matchers.equalTo("7.17.0"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.17.5"), Matchers.equalTo("7.17.5"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.17.1234"), Matchers.equalTo("7.17.1234"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.18.0"), Matchers.equalTo("7.18.0"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.17.x"), Matchers.equalTo("7.17.0"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.17.5-SNAPSHOT"), Matchers.equalTo("7.17.0"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.17.6b"), Matchers.equalTo("7.17.0"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7.16.0"), Matchers.equalTo("7.17.0"));
-        // when we get to version 7.2147483648.0 we will have to rethink our approach, but for now we return 7.17.0 with an integer overflow
-        assertThat(NodeEnvironment.getBestDowngradeVersion("7." + Integer.MAX_VALUE + "0.0"), Matchers.equalTo("7.17.0"));
-        assertThat(NodeEnvironment.getBestDowngradeVersion("foo"), Matchers.equalTo("7.17.0"));
+        assertThat(
+            NodeEnvironment.getBestDowngradeVersion(BuildVersion.fromString("8.18.0")),
+            Matchers.equalTo(BuildVersion.fromString("8.18.0"))
+        );
+        assertThat(
+            NodeEnvironment.getBestDowngradeVersion(BuildVersion.fromString("8.18.5")),
+            Matchers.equalTo(BuildVersion.fromString("8.18.5"))
+        );
+        assertThat(
+            NodeEnvironment.getBestDowngradeVersion(BuildVersion.fromString("8.18.12")),
+            Matchers.equalTo(BuildVersion.fromString("8.18.12"))
+        );
+        assertThat(
+            NodeEnvironment.getBestDowngradeVersion(BuildVersion.fromString("8.19.0")),
+            Matchers.equalTo(BuildVersion.fromString("8.19.0"))
+        );
+        assertThat(
+            NodeEnvironment.getBestDowngradeVersion(BuildVersion.fromString("8.17.0")),
+            Matchers.equalTo(BuildVersion.fromString("8.18.0"))
+        );
+        assertThat(
+            NodeEnvironment.getBestDowngradeVersion(BuildVersion.fromString("7.17.0")),
+            Matchers.equalTo(BuildVersion.fromString("8.18.0"))
+        );
     }
 
     private void verifyFailsOnShardData(Settings settings, Path indexPath, String shardDataDirName) {

server/src/test/java/org/elasticsearch/env/NodeMetadataTests.java

@@ -9,12 +9,11 @@
 package org.elasticsearch.env;
 
 import org.elasticsearch.Build;
+import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.Version;
 import org.elasticsearch.core.Tuple;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.gateway.MetadataStateFormat;
 import org.elasticsearch.index.IndexVersion;
-import org.elasticsearch.index.IndexVersions;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.test.EqualsHashCodeTestUtils;
 import org.elasticsearch.test.VersionUtils;
@@ -28,6 +27,7 @@
 import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.endsWith;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.startsWith;
 
@@ -80,22 +80,20 @@ public void testEqualsHashcodeSerialization() {
         );
     }
 
-    @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA)
-    @AwaitsFix(bugUrl = "as mentioned in the comment below, the behavior here is changing for 9.0 so this test needs updating")
-    public void testReadsFormatWithoutVersion() throws IOException {
-        // the behaviour tested here is only appropriate if the current version is compatible with versions 7 and earlier
-        assertTrue(IndexVersions.MINIMUM_COMPATIBLE.onOrBefore(IndexVersions.V_7_0_0));
-        // when the current version is incompatible with version 7, the behaviour should change to reject files like the given resource
-        // which do not have the version field
-
+    public void testFailsToReadFormatWithoutVersion() throws IOException {
         final Path tempDir = createTempDir();
         final Path stateDir = Files.createDirectory(tempDir.resolve(MetadataStateFormat.STATE_DIR_NAME));
         final InputStream resource = this.getClass().getResourceAsStream("testReadsFormatWithoutVersion.binary");
         assertThat(resource, notNullValue());
         Files.copy(resource, stateDir.resolve(NodeMetadata.FORMAT.getStateFileName(between(0, Integer.MAX_VALUE))));
-        final NodeMetadata nodeMetadata = NodeMetadata.FORMAT.loadLatestState(logger, xContentRegistry(), tempDir);
-        assertThat(nodeMetadata.nodeId(), equalTo("y6VUVMSaStO4Tz-B5BxcOw"));
-        assertThat(nodeMetadata.nodeVersion(), equalTo(BuildVersion.fromVersionId(0)));
+
+        ElasticsearchException ex = expectThrows(
+            ElasticsearchException.class,
+            () -> NodeMetadata.FORMAT.loadLatestState(logger, xContentRegistry(), tempDir)
+        );
+        Throwable rootCause = ex.getRootCause();
+        assertThat(rootCause, instanceOf(IllegalStateException.class));
+        assertThat("Node version is required in node metadata", equalTo(rootCause.getMessage()));
     }
 
     public void testUpgradesLegitimateVersions() {
@@ -155,11 +153,9 @@ public void testDoesNotUpgradeAncientVersion() {
         );
     }
 
-    @UpdateForV9(owner = UpdateForV9.Owner.CORE_INFRA)
-    @AwaitsFix(bugUrl = "Needs to be updated for 9.0 version bump")
     public void testUpgradeMarksPreviousVersion() {
         final String nodeId = randomAlphaOfLength(10);
-        final Version version = VersionUtils.randomVersionBetween(random(), Version.CURRENT.minimumCompatibilityVersion(), Version.V_8_0_0);
+        final Version version = VersionUtils.randomVersionBetween(random(), Version.CURRENT.minimumCompatibilityVersion(), Version.V_9_0_0);
         final BuildVersion buildVersion = BuildVersion.fromVersionId(version.id());
 
         final NodeMetadata nodeMetadata = new NodeMetadata(nodeId, buildVersion, IndexVersion.current()).upgradeToCurrentVersion();

server/src/test/java/org/elasticsearch/index/IndexVersionTests.java

@@ -153,6 +153,7 @@ public void testMax() {
     public void testGetMinimumCompatibleIndexVersion() {
         assertThat(IndexVersion.getMinimumCompatibleIndexVersion(7170099), equalTo(IndexVersion.fromId(6000099)));
         assertThat(IndexVersion.getMinimumCompatibleIndexVersion(8000099), equalTo(IndexVersion.fromId(7000099)));
+        assertThat(IndexVersion.getMinimumCompatibleIndexVersion(9000099), equalTo(IndexVersion.fromId(8000099)));
         assertThat(IndexVersion.getMinimumCompatibleIndexVersion(10000000), equalTo(IndexVersion.fromId(9000000)));
     }
 

test/framework/src/main/java/org/elasticsearch/index/mapper/MapperTestCase.java

@@ -105,8 +105,6 @@
  */
 public abstract class MapperTestCase extends MapperServiceTestCase {
 
-    public static final IndexVersion DEPRECATED_BOOST_INDEX_VERSION = IndexVersions.V_7_10_0;
-
     protected abstract void minimalMapping(XContentBuilder b) throws IOException;
 
     /**