Remove the need for _UNRELEASED suffix in versions (#24798)

Removes the need for the `_UNRELEASED` suffix on versions by detecting if a version should be unreleased or not based on the versions around it. This should make it simpler to automate the task of adding a new version label.

62 files changed, 440 insertions, 317 deletions

diff --git a/build.gradle b/build.gradle
index 20467d842f..7d6b760a19 100644
--- a/build.gradle
+++ b/build.gradle
@@ -62,7 +62,12 @@ configure(subprojects.findAll { it.projectDir.toPath().startsWith(rootPath) }) {
   }
 }
 
-// introspect all versions of ES that may be tested agains for backwards compatibility
+/* Introspect all versions of ES that may be tested agains for backwards
+ * compatibility. It is *super* important that this logic is the same as the
+ * logic in VersionUtils.java, modulo alphas, betas, and rcs which are ignored
+ * in gradle because they don't have any backwards compatibility guarantees
+ * but are not ignored in VersionUtils.java because the tests expect them not
+ * to be. */
 Version currentVersion = Version.fromString(VersionProperties.elasticsearch.minus('-SNAPSHOT'))
 int prevMajor = currentVersion.major - 1
 File versionFile = file('core/src/main/java/org/elasticsearch/Version.java')
@@ -72,13 +77,14 @@ List<Version> versions = []
 int prevMinorIndex = -1 // index in the versions list of the last minor from the prev major
 int lastPrevMinor = -1 // the minor version number from the prev major we most recently seen
 for (String line : versionLines) {
-  Matcher match = line =~ /\W+public static final Version V_(\d+)_(\d+)_(\d+)(_UNRELEASED)? .*/
+  /* Note that this skips alphas and betas which is fine because they aren't
+   * compatible with anything. */
+  Matcher match = line =~ /\W+public static final Version V_(\d+)_(\d+)_(\d+) .*/
   if (match.matches()) {
     int major = Integer.parseInt(match.group(1))
     int minor = Integer.parseInt(match.group(2))
     int bugfix = Integer.parseInt(match.group(3))
-    boolean unreleased = match.group(4) != null
-    Version foundVersion = new Version(major, minor, bugfix, false, unreleased)
+    Version foundVersion = new Version(major, minor, bugfix, false)
     if (currentVersion != foundVersion) {
       versions.add(foundVersion)
     }
@@ -98,8 +104,11 @@ if (currentVersion.bugfix == 0) {
   // unreleased version of closest branch. So for those cases, the version includes -SNAPSHOT,
   // and the bwc distribution will checkout and build that version.
   Version last = versions[-1]
-  versions[-1] = new Version(last.major, last.minor, last.bugfix,
-      true, last.unreleased)
+  versions[-1] = new Version(last.major, last.minor, last.bugfix, true)
+  if (last.bugfix == 0) {
+    versions[-2] = new Version(
+        versions[-2].major, versions[-2].minor, versions[-2].bugfix, true)
+  }
 }
 
 // injecting groovy property variables into all projects
@@ -114,6 +123,44 @@ allprojects {
   }
 }
 
+task('verifyVersions') {
+  description 'Verifies that all released versions that are indexed compatible are listed in Version.java.'
+  group 'Verification'
+  enabled = false == gradle.startParameter.isOffline()
+  doLast {
+    // Read the list from maven central
+    Node xml
+    new URL('https://repo1.maven.org/maven2/org/elasticsearch/elasticsearch/maven-metadata.xml').openStream().withStream { s ->
+        xml = new XmlParser().parse(s)
+    }
+    Set<String> knownVersions = new TreeSet<>(xml.versioning.versions.version.collect { it.text() }.findAll { it ==~ /\d\.\d\.\d/ })
+
+    // Limit the known versions to those that should be index compatible
+    knownVersions = knownVersions.findAll { Integer.parseInt(it.split('\\.')[0]) >= prevMajor }
+
+    /* Limit the listed versions to those that have been marked as released.
+     * Versions not marked as released don't get the same testing and we want
+     * to make sure that we flip all unreleased versions to released as soon
+     * as possible after release. */
+    Set<String> actualVersions = new TreeSet<>(
+      indexCompatVersions
+        .findAll { false == it.snapshot }
+        .collect { it.toString() })
+
+    // TODO this is almost certainly going to fail on 5.4 when we release 5.5.0
+
+    // Finally, compare!
+    if (!knownVersions.equals(actualVersions)) {
+      throw new GradleException("out-of-date versions\nActual  :" +
+        actualVersions + "\nExpected:" + knownVersions +
+        "; update Version.java")
+    }
+  }
+}
+task('precommit') {
+  dependsOn(verifyVersions)
+}
+
 subprojects {
   project.afterEvaluate {
     // include license and notice in jars
diff --git a/buildSrc/src/main/groovy/org/elasticsearch/gradle/Version.groovy b/buildSrc/src/main/groovy/org/elasticsearch/gradle/Version.groovy
index 03fe4c3428..1c236c6c44 100644
--- a/buildSrc/src/main/groovy/org/elasticsearch/gradle/Version.groovy
+++ b/buildSrc/src/main/groovy/org/elasticsearch/gradle/Version.groovy
@@ -29,20 +29,14 @@ public class Version {
     final int bugfix
     final int id
     final boolean snapshot
-    /**
-     * Is the vesion listed as {@code _UNRELEASED} in Version.java.
-     */
-    final boolean unreleased
 
-    public Version(int major, int minor, int bugfix, boolean snapshot,
-            boolean unreleased) {
+    public Version(int major, int minor, int bugfix, boolean snapshot) {
         this.major = major
         this.minor = minor
         this.bugfix = bugfix
         this.snapshot = snapshot
         this.id = major * 100000 + minor * 1000 + bugfix * 10 +
             (snapshot ? 1 : 0)
-        this.unreleased = unreleased
     }
 
     public static Version fromString(String s) {
@@ -54,7 +48,7 @@ public class Version {
             bugfix = bugfix.split('-')[0]
         }
         return new Version(parts[0] as int, parts[1] as int, bugfix as int,
-            snapshot, false)
+            snapshot)
     }
 
     @Override
diff --git a/core/build.gradle b/core/build.gradle
index 516aeb1d0e..141c647f48 100644
--- a/core/build.gradle
+++ b/core/build.gradle
@@ -277,43 +277,3 @@ if (isEclipse == false || project.path == ":core-tests") {
   check.dependsOn integTest
   integTest.mustRunAfter test
 }
-
-task('verifyVersions') {
-  description 'Verifies that all released versions that are indexed compatible are listed in Version.java.'
-  group 'Verification'
-  enabled = false == gradle.startParameter.isOffline()
-  doLast {
-    // Read the list from maven central
-    Node xml
-    new URL('https://repo1.maven.org/maven2/org/elasticsearch/elasticsearch/maven-metadata.xml').openStream().withStream { s ->
-        xml = new XmlParser().parse(s)
-    }
-    Set<String> knownVersions = new TreeSet<>(xml.versioning.versions.version.collect { it.text() }.findAll { it ==~ /\d\.\d\.\d/ })
-
-    // Limit the known versions to those that should be wire compatible
-    String currentVersion = versions.elasticsearch.minus('-SNAPSHOT')
-    int prevMajor = Integer.parseInt(currentVersion.split('\\.')[0]) - 1
-    if (prevMajor == 4) {
-      // 4 didn't exist, it was 2.
-      prevMajor = 2;
-    }
-    knownVersions = knownVersions.findAll { Integer.parseInt(it.split('\\.')[0]) >= prevMajor }
-
-    /* Limit the listed versions to those that have been marked as released.
-     * Versions not marked as released don't get the same testing and we want
-     * to make sure that we flip all unreleased versions to released as soon
-     * as possible after release. */
-    Set<String> actualVersions = new TreeSet<>(
-      indexCompatVersions
-        .findAll { false == it.unreleased }
-        .collect { it.toString() })
-
-    // Finally, compare!
-    if (!knownVersions.equals(actualVersions)) {
-      throw new GradleException("out-of-date versions\nActual  :" +
-        actualVersions + "\nExpected:" + knownVersions +
-        "; update Version.java")
-    }
-  }
-}
-check.dependsOn(verifyVersions)
diff --git a/core/src/main/java/org/elasticsearch/Version.java b/core/src/main/java/org/elasticsearch/Version.java
index 15417c5433..a9a63b151a 100644
--- a/core/src/main/java/org/elasticsearch/Version.java
+++ b/core/src/main/java/org/elasticsearch/Version.java
@@ -74,15 +74,17 @@ public class Version implements Comparable<Version> {
     public static final Version V_5_3_2 = new Version(V_5_3_2_ID, org.apache.lucene.util.Version.LUCENE_6_4_2);
     public static final int V_5_4_0_ID = 5040099;
     public static final Version V_5_4_0 = new Version(V_5_4_0_ID, org.apache.lucene.util.Version.LUCENE_6_5_0);
-    public static final int V_5_5_0_ID_UNRELEASED = 5050099;
-    public static final Version V_5_5_0_UNRELEASED = new Version(V_5_5_0_ID_UNRELEASED, org.apache.lucene.util.Version.LUCENE_6_5_1);
-    public static final int V_6_0_0_alpha1_ID_UNRELEASED = 6000001;
-    public static final Version V_6_0_0_alpha1_UNRELEASED =
-            new Version(V_6_0_0_alpha1_ID_UNRELEASED, org.apache.lucene.util.Version.LUCENE_7_0_0);
-    public static final int V_6_0_0_alpha2_ID_UNRELEASED = 6000002;
-    public static final Version V_6_0_0_alpha2_UNRELEASED =
-            new Version(V_6_0_0_alpha2_ID_UNRELEASED, org.apache.lucene.util.Version.LUCENE_7_0_0);
-    public static final Version CURRENT = V_6_0_0_alpha2_UNRELEASED;
+    public static final int V_5_4_1_ID = 5040199;
+    public static final Version V_5_4_1 = new Version(V_5_4_1_ID, org.apache.lucene.util.Version.LUCENE_6_5_0);
+    public static final int V_5_5_0_ID = 5050099;
+    public static final Version V_5_5_0 = new Version(V_5_5_0_ID, org.apache.lucene.util.Version.LUCENE_6_5_0);
+    public static final int V_6_0_0_alpha1_ID = 6000001;
+    public static final Version V_6_0_0_alpha1 =
+            new Version(V_6_0_0_alpha1_ID, org.apache.lucene.util.Version.LUCENE_7_0_0);
+    public static final int V_6_0_0_alpha2_ID = 6000002;
+    public static final Version V_6_0_0_alpha2 =
+            new Version(V_6_0_0_alpha2_ID, org.apache.lucene.util.Version.LUCENE_7_0_0);
+    public static final Version CURRENT = V_6_0_0_alpha2;
 
     // unreleased versions must be added to the above list with the suffix _UNRELEASED (with the exception of CURRENT)
 
@@ -97,12 +99,14 @@ public class Version implements Comparable<Version> {
 
     public static Version fromId(int id) {
         switch (id) {
-            case V_6_0_0_alpha2_ID_UNRELEASED:
-                return V_6_0_0_alpha2_UNRELEASED;
-            case V_6_0_0_alpha1_ID_UNRELEASED:
-                return V_6_0_0_alpha1_UNRELEASED;
-            case V_5_5_0_ID_UNRELEASED:
-                return V_5_5_0_UNRELEASED;
+            case V_6_0_0_alpha2_ID:
+                return V_6_0_0_alpha2;
+            case V_6_0_0_alpha1_ID:
+                return V_6_0_0_alpha1;
+            case V_5_5_0_ID:
+                return V_5_5_0;
+            case V_5_4_1_ID:
+                return V_5_4_1;
             case V_5_4_0_ID:
                 return V_5_4_0;
             case V_5_3_2_ID:
diff --git a/core/src/main/java/org/elasticsearch/action/DocWriteResponse.java b/core/src/main/java/org/elasticsearch/action/DocWriteResponse.java
index aacb0ff17e..64f6302527 100644
--- a/core/src/main/java/org/elasticsearch/action/DocWriteResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/DocWriteResponse.java
@@ -261,7 +261,7 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
         type = in.readString();
         id = in.readString();
         version = in.readZLong();
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             seqNo = in.readZLong();
             primaryTerm = in.readVLong();
         } else {
@@ -279,7 +279,7 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
         out.writeString(type);
         out.writeString(id);
         out.writeZLong(version);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeZLong(seqNo);
             out.writeVLong(primaryTerm);
         }
diff --git a/core/src/main/java/org/elasticsearch/action/admin/cluster/state/ClusterStateResponse.java b/core/src/main/java/org/elasticsearch/action/admin/cluster/state/ClusterStateResponse.java
index 4fc1c9c96f..cdc869e529 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/cluster/state/ClusterStateResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/cluster/state/ClusterStateResponse.java
@@ -79,7 +79,7 @@ public class ClusterStateResponse extends ActionResponse {
         super.readFrom(in);
         clusterName = new ClusterName(in);
         clusterState = ClusterState.readFrom(in, null);
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             totalCompressedSize = new ByteSizeValue(in);
         } else {
             // in a mixed cluster, if a pre 6.0 node processes the get cluster state
@@ -95,7 +95,7 @@ public class ClusterStateResponse extends ActionResponse {
         super.writeTo(out);
         clusterName.writeTo(out);
         clusterState.writeTo(out);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             totalCompressedSize.writeTo(out);
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/action/admin/indices/create/CreateIndexRequest.java b/core/src/main/java/org/elasticsearch/action/admin/indices/create/CreateIndexRequest.java
index a294d6cb77..0139726903 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/indices/create/CreateIndexRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/indices/create/CreateIndexRequest.java
@@ -492,7 +492,7 @@ public class CreateIndexRequest extends AcknowledgedRequest<CreateIndexRequest>
         for (int i = 0; i < size; i++) {
             final String type = in.readString();
             String source = in.readString();
-            if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) { // TODO change to 5.3.0 after backport
+            if (in.getVersion().before(Version.V_6_0_0_alpha1)) { // TODO change to 5.3.0 after backport
                 // we do not know the content type that comes from earlier versions so we autodetect and convert
                 source = XContentHelper.convertToJson(new BytesArray(source), false, false, XContentFactory.xContentType(source));
             }
diff --git a/core/src/main/java/org/elasticsearch/action/admin/indices/shards/IndicesShardStoresResponse.java b/core/src/main/java/org/elasticsearch/action/admin/indices/shards/IndicesShardStoresResponse.java
index 6ad389c13d..8cded12b03 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/indices/shards/IndicesShardStoresResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/indices/shards/IndicesShardStoresResponse.java
@@ -21,6 +21,7 @@ package org.elasticsearch.action.admin.indices.shards;
 
 import com.carrotsearch.hppc.cursors.IntObjectCursor;
 import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
+
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionResponse;
@@ -34,7 +35,6 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Streamable;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.index.shard.ShardStateMetaData;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -165,7 +165,7 @@ public class IndicesShardStoresResponse extends ActionResponse implements ToXCon
         @Override
         public void readFrom(StreamInput in) throws IOException {
             node = new DiscoveryNode(in);
-            if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
                 // legacy version
                 in.readLong();
             }
@@ -179,7 +179,7 @@ public class IndicesShardStoresResponse extends ActionResponse implements ToXCon
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             node.writeTo(out);
-            if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
                 // legacy version
                 out.writeLong(-1L);
             }
diff --git a/core/src/main/java/org/elasticsearch/action/admin/indices/stats/ShardStats.java b/core/src/main/java/org/elasticsearch/action/admin/indices/stats/ShardStats.java
index 150b7c6a52..3d1e567fa1 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/indices/stats/ShardStats.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/indices/stats/ShardStats.java
@@ -104,7 +104,7 @@ public class ShardStats implements Streamable, Writeable, ToXContent {
         statePath = in.readString();
         dataPath = in.readString();
         isCustomDataPath = in.readBoolean();
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             seqNoStats = in.readOptionalWriteable(SeqNoStats::new);
         }
     }
@@ -117,7 +117,7 @@ public class ShardStats implements Streamable, Writeable, ToXContent {
         out.writeString(statePath);
         out.writeString(dataPath);
         out.writeBoolean(isCustomDataPath);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeOptionalWriteable(seqNoStats);
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequest.java b/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequest.java
index 18060d57f0..99ad163f48 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequest.java
@@ -475,7 +475,7 @@ public class PutIndexTemplateRequest extends MasterNodeRequest<PutIndexTemplateR
         cause = in.readString();
         name = in.readString();
 
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             indexPatterns = in.readList(StreamInput::readString);
         } else {
             indexPatterns = Collections.singletonList(in.readString());
@@ -512,7 +512,7 @@ public class PutIndexTemplateRequest extends MasterNodeRequest<PutIndexTemplateR
         super.writeTo(out);
         out.writeString(cause);
         out.writeString(name);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeStringList(indexPatterns);
         } else {
             out.writeString(indexPatterns.size() > 0 ? indexPatterns.get(0) : "");
diff --git a/core/src/main/java/org/elasticsearch/action/bulk/BulkItemRequest.java b/core/src/main/java/org/elasticsearch/action/bulk/BulkItemRequest.java
index 50da1476f4..39e03277c3 100644
--- a/core/src/main/java/org/elasticsearch/action/bulk/BulkItemRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/bulk/BulkItemRequest.java
@@ -78,7 +78,7 @@ public class BulkItemRequest implements Streamable {
         if (in.readBoolean()) {
             primaryResponse = BulkItemResponse.readBulkItem(in);
         }
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) { // TODO remove once backported
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) { // TODO remove once backported
             boolean ignoreOnReplica = in.readBoolean();
             if (ignoreOnReplica == false && primaryResponse != null) {
                 assert primaryResponse.isFailed() == false : "expected no failure on the primary response";
@@ -89,7 +89,7 @@ public class BulkItemRequest implements Streamable {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVInt(id);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) { // TODO remove once backported
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) { // TODO remove once backported
             // old nodes expect updated version and version type on the request
             if (primaryResponse != null) {
                 request.version(primaryResponse.getVersion());
@@ -102,7 +102,7 @@ public class BulkItemRequest implements Streamable {
             DocWriteRequest.writeDocumentRequest(out, request);
         }
         out.writeOptionalStreamable(primaryResponse);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) { // TODO remove once backported
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) { // TODO remove once backported
             if (primaryResponse != null) {
                 out.writeBoolean(primaryResponse.isFailed()
                         || primaryResponse.getResponse().getResult() == DocWriteResponse.Result.NOOP);
diff --git a/core/src/main/java/org/elasticsearch/action/bulk/BulkItemResponse.java b/core/src/main/java/org/elasticsearch/action/bulk/BulkItemResponse.java
index 0ddd01187a..daf10521f9 100644
--- a/core/src/main/java/org/elasticsearch/action/bulk/BulkItemResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/bulk/BulkItemResponse.java
@@ -211,7 +211,7 @@ public class BulkItemResponse implements Streamable, StatusToXContentObject {
             id = in.readOptionalString();
             cause = in.readException();
             status = ExceptionsHelper.status(cause);
-            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 seqNo = in.readZLong();
             } else {
                 seqNo = SequenceNumbersService.UNASSIGNED_SEQ_NO;
@@ -224,7 +224,7 @@ public class BulkItemResponse implements Streamable, StatusToXContentObject {
             out.writeString(getType());
             out.writeOptionalString(getId());
             out.writeException(getCause());
-            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 out.writeZLong(getSeqNo());
             }
         }
diff --git a/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesRequest.java b/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesRequest.java
index 7a47405d92..b04f882076 100644
--- a/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesRequest.java
@@ -78,7 +78,7 @@ public final class FieldCapabilitiesRequest extends ActionRequest implements Ind
     public void readFrom(StreamInput in) throws IOException {
         super.readFrom(in);
         fields = in.readStringArray();
-        if (in.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_5_5_0)) {
             indices = in.readStringArray();
             indicesOptions = IndicesOptions.readIndicesOptions(in);
             mergeResults = in.readBoolean();
@@ -91,7 +91,7 @@ public final class FieldCapabilitiesRequest extends ActionRequest implements Ind
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
         out.writeStringArray(fields);
-        if (out.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_5_5_0)) {
             out.writeStringArray(indices);
             indicesOptions.writeIndicesOptions(out);
             out.writeBoolean(mergeResults);
diff --git a/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesResponse.java b/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesResponse.java
index 00c424e1fe..ae5db58356 100644
--- a/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/fieldcaps/FieldCapabilitiesResponse.java
@@ -86,7 +86,7 @@ public class FieldCapabilitiesResponse extends ActionResponse implements ToXCont
         super.readFrom(in);
         this.responseMap =
             in.readMap(StreamInput::readString, FieldCapabilitiesResponse::readField);
-        if (in.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_5_5_0)) {
             indexResponses = in.readList(FieldCapabilitiesIndexResponse::new);
         } else {
             indexResponses = Collections.emptyList();
@@ -101,7 +101,7 @@ public class FieldCapabilitiesResponse extends ActionResponse implements ToXCont
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
         out.writeMap(responseMap, StreamOutput::writeString, FieldCapabilitiesResponse::writeField);
-        if (out.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_5_5_0)) {
             out.writeList(indexResponses);
         }
 
diff --git a/core/src/main/java/org/elasticsearch/action/index/IndexRequest.java b/core/src/main/java/org/elasticsearch/action/index/IndexRequest.java
index ee9a5b2dfe..552780e739 100644
--- a/core/src/main/java/org/elasticsearch/action/index/IndexRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/index/IndexRequest.java
@@ -523,7 +523,7 @@ public class IndexRequest extends ReplicatedWriteRequest<IndexRequest> implement
         id = in.readOptionalString();
         routing = in.readOptionalString();
         parent = in.readOptionalString();
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             in.readOptionalString(); // timestamp
             in.readOptionalWriteable(TimeValue::new); // ttl
         }
@@ -548,7 +548,7 @@ public class IndexRequest extends ReplicatedWriteRequest<IndexRequest> implement
         out.writeOptionalString(id);
         out.writeOptionalString(routing);
         out.writeOptionalString(parent);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             // Serialize a fake timestamp. 5.x expect this value to be set by the #process method so we can't use null.
             // On the other hand, indices created on 5.x do not index the timestamp field.  Therefore passing a 0 (or any value) for
             // the transport layer OK as it will be ignored.
diff --git a/core/src/main/java/org/elasticsearch/action/support/replication/TransportReplicationAction.java b/core/src/main/java/org/elasticsearch/action/support/replication/TransportReplicationAction.java
index b3dcf6fe1e..946692f182 100644
--- a/core/src/main/java/org/elasticsearch/action/support/replication/TransportReplicationAction.java
+++ b/core/src/main/java/org/elasticsearch/action/support/replication/TransportReplicationAction.java
@@ -1011,7 +1011,7 @@ public abstract class TransportReplicationAction<
 
         @Override
         public void readFrom(StreamInput in) throws IOException {
-            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 super.readFrom(in);
                 localCheckpoint = in.readZLong();
                 allocationId = in.readString();
@@ -1022,7 +1022,7 @@ public abstract class TransportReplicationAction<
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
-            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 super.writeTo(out);
                 out.writeZLong(localCheckpoint);
                 out.writeString(allocationId);
@@ -1191,7 +1191,7 @@ public abstract class TransportReplicationAction<
         @Override
         public void readFrom(StreamInput in) throws IOException {
             super.readFrom(in);
-            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 globalCheckpoint = in.readZLong();
             }
         }
@@ -1199,7 +1199,7 @@ public abstract class TransportReplicationAction<
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             super.writeTo(out);
-            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 out.writeZLong(globalCheckpoint);
             }
         }
diff --git a/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java b/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java
index 133c20411f..2caaa0bddf 100644
--- a/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java
+++ b/core/src/main/java/org/elasticsearch/cluster/block/ClusterBlock.java
@@ -138,7 +138,7 @@ public class ClusterBlock implements Streamable, ToXContent {
         retryable = in.readBoolean();
         disableStatePersistence = in.readBoolean();
         status = RestStatus.readFrom(in);
-        if (in.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_5_5_0)) {
             allowReleaseResources = in.readBoolean();
         } else {
             allowReleaseResources = false;
@@ -156,7 +156,7 @@ public class ClusterBlock implements Streamable, ToXContent {
         out.writeBoolean(retryable);
         out.writeBoolean(disableStatePersistence);
         RestStatus.writeTo(out, status);
-        if (out.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_5_5_0)) {
             out.writeBoolean(allowReleaseResources);
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/cluster/metadata/IndexTemplateMetaData.java b/core/src/main/java/org/elasticsearch/cluster/metadata/IndexTemplateMetaData.java
index 5bba34904d..b22106d971 100644
--- a/core/src/main/java/org/elasticsearch/cluster/metadata/IndexTemplateMetaData.java
+++ b/core/src/main/java/org/elasticsearch/cluster/metadata/IndexTemplateMetaData.java
@@ -210,7 +210,7 @@ public class IndexTemplateMetaData extends AbstractDiffable<IndexTemplateMetaDat
     public static IndexTemplateMetaData readFrom(StreamInput in) throws IOException {
         Builder builder = new Builder(in.readString());
         builder.order(in.readInt());
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             builder.patterns(in.readList(StreamInput::readString));
         } else {
             builder.patterns(Collections.singletonList(in.readString()));
@@ -245,7 +245,7 @@ public class IndexTemplateMetaData extends AbstractDiffable<IndexTemplateMetaDat
     public void writeTo(StreamOutput out) throws IOException {
         out.writeString(name);
         out.writeInt(order);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeStringList(patterns);
         } else {
             out.writeString(patterns.size() > 0 ? patterns.get(0) : "");
diff --git a/core/src/main/java/org/elasticsearch/cluster/metadata/MappingMetaData.java b/core/src/main/java/org/elasticsearch/cluster/metadata/MappingMetaData.java
index 08d5211e12..1f6aeb1122 100644
--- a/core/src/main/java/org/elasticsearch/cluster/metadata/MappingMetaData.java
+++ b/core/src/main/java/org/elasticsearch/cluster/metadata/MappingMetaData.java
@@ -196,7 +196,7 @@ public class MappingMetaData extends AbstractDiffable<MappingMetaData> {
         source().writeTo(out);
         // routing
         out.writeBoolean(routing().required());
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             // timestamp
             out.writeBoolean(false); // enabled
             out.writeString(DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER.format());
@@ -233,7 +233,7 @@ public class MappingMetaData extends AbstractDiffable<MappingMetaData> {
         source = CompressedXContent.readCompressedString(in);
         // routing
         routing = new Routing(in.readBoolean());
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             // timestamp
             boolean enabled = in.readBoolean();
             if (enabled) {
diff --git a/core/src/main/java/org/elasticsearch/cluster/routing/OperationRouting.java b/core/src/main/java/org/elasticsearch/cluster/routing/OperationRouting.java
index 6068d61aae..8a88ee1751 100644
--- a/core/src/main/java/org/elasticsearch/cluster/routing/OperationRouting.java
+++ b/core/src/main/java/org/elasticsearch/cluster/routing/OperationRouting.java
@@ -179,7 +179,7 @@ public class OperationRouting extends AbstractComponent {
         }
         // if not, then use it as the index
         int routingHash = Murmur3HashFunction.hash(preference);
-        if (nodes.getMinNodeVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (nodes.getMinNodeVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             // The AllocationService lists shards in a fixed order based on nodes
             // so earlier versions of this class would have a tendency to
             // select the same node across different shardIds.
diff --git a/core/src/main/java/org/elasticsearch/common/settings/Settings.java b/core/src/main/java/org/elasticsearch/common/settings/Settings.java
index d3071eb58f..b0a1f2ed09 100644
--- a/core/src/main/java/org/elasticsearch/common/settings/Settings.java
+++ b/core/src/main/java/org/elasticsearch/common/settings/Settings.java
@@ -344,7 +344,7 @@ public final class Settings implements ToXContent {
         final String setting,
         final Boolean defaultValue,
         final DeprecationLogger deprecationLogger) {
-        if (indexVersion.before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (indexVersion.before(Version.V_6_0_0_alpha1)) {
             //Only emit a warning if the setting's value is not a proper boolean
             final String value = get(setting, "false");
             if (Booleans.isBoolean(value) == false) {
diff --git a/core/src/main/java/org/elasticsearch/common/transport/TransportAddress.java b/core/src/main/java/org/elasticsearch/common/transport/TransportAddress.java
index 5ed7f40fad..965811f42a 100644
--- a/core/src/main/java/org/elasticsearch/common/transport/TransportAddress.java
+++ b/core/src/main/java/org/elasticsearch/common/transport/TransportAddress.java
@@ -78,7 +78,7 @@ public final class TransportAddress implements Writeable {
      * {@link Version#V_5_0_2} as the hostString was not serialized
      */
     public TransportAddress(StreamInput in, @Nullable String hostString) throws IOException {
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) { // bwc layer for 5.x where we had more than one transport address
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) { // bwc layer for 5.x where we had more than one transport address
             final short i = in.readShort();
             if(i != 1) { // we fail hard to ensure nobody tries to use some custom transport address impl even if that is difficult to add
                 throw new AssertionError("illegal transport ID from node of version: " + in.getVersion()  + " got: " + i + " expected: 1");
@@ -101,7 +101,7 @@ public final class TransportAddress implements Writeable {
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             out.writeShort((short)1); // this maps to InetSocketTransportAddress in 5.x
         }
         byte[] bytes = address.getAddress().getAddress();  // 4 bytes (IPv4) or 16 bytes (IPv6)
diff --git a/core/src/main/java/org/elasticsearch/gateway/TransportNodesListGatewayStartedShards.java b/core/src/main/java/org/elasticsearch/gateway/TransportNodesListGatewayStartedShards.java
index 0dc9647c12..f2b046acd9 100644
--- a/core/src/main/java/org/elasticsearch/gateway/TransportNodesListGatewayStartedShards.java
+++ b/core/src/main/java/org/elasticsearch/gateway/TransportNodesListGatewayStartedShards.java
@@ -290,7 +290,7 @@ public class TransportNodesListGatewayStartedShards extends
         @Override
         public void readFrom(StreamInput in) throws IOException {
             super.readFrom(in);
-            if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
                 // legacy version
                 in.readLong();
             }
@@ -304,7 +304,7 @@ public class TransportNodesListGatewayStartedShards extends
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             super.writeTo(out);
-            if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
                 // legacy version
                 out.writeLong(-1L);
             }
diff --git a/core/src/main/java/org/elasticsearch/index/IndexSortConfig.java b/core/src/main/java/org/elasticsearch/index/IndexSortConfig.java
index 1d3f5f0fc2..7ec5acbe3a 100644
--- a/core/src/main/java/org/elasticsearch/index/IndexSortConfig.java
+++ b/core/src/main/java/org/elasticsearch/index/IndexSortConfig.java
@@ -120,13 +120,13 @@ public final class IndexSortConfig {
             .map((name) -> new FieldSortSpec(name))
             .toArray(FieldSortSpec[]::new);
 
-        if (sortSpecs.length > 0 && indexSettings.getIndexVersionCreated().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (sortSpecs.length > 0 && indexSettings.getIndexVersionCreated().before(Version.V_6_0_0_alpha1)) {
             /**
              * This index might be assigned to a node where the index sorting feature is not available
              * (ie. versions prior to {@link Version.V_6_0_0_alpha1_UNRELEASED}) so we must fail here rather than later.
              */
             throw new IllegalArgumentException("unsupported index.version.created:" + indexSettings.getIndexVersionCreated() +
-                ", can't set index.sort on versions prior to " + Version.V_6_0_0_alpha1_UNRELEASED);
+                ", can't set index.sort on versions prior to " + Version.V_6_0_0_alpha1);
         }
 
         if (INDEX_SORT_ORDER_SETTING.exists(settings)) {
diff --git a/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java b/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java
index 03007d96b9..ca653ff412 100644
--- a/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java
+++ b/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java
@@ -550,14 +550,14 @@ public class InternalEngine extends Engine {
     }
 
     private boolean assertIncomingSequenceNumber(final Engine.Operation.Origin origin, final long seqNo) {
-        if (engineConfig.getIndexSettings().getIndexVersionCreated().before(Version.V_6_0_0_alpha1_UNRELEASED) && origin == Operation.Origin.LOCAL_TRANSLOG_RECOVERY) {
+        if (engineConfig.getIndexSettings().getIndexVersionCreated().before(Version.V_6_0_0_alpha1) && origin == Operation.Origin.LOCAL_TRANSLOG_RECOVERY) {
             // legacy support
             assert seqNo == SequenceNumbersService.UNASSIGNED_SEQ_NO : "old op recovering but it already has a seq no.;" +
                 " index version: " + engineConfig.getIndexSettings().getIndexVersionCreated() + ", seqNo: " + seqNo;
         } else if (origin == Operation.Origin.PRIMARY) {
             // sequence number should not be set when operation origin is primary
             assert seqNo == SequenceNumbersService.UNASSIGNED_SEQ_NO : "primary ops should never have an assigned seq no.; seqNo: " + seqNo;
-        } else if (engineConfig.getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        } else if (engineConfig.getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1)) {
             // sequence number should be set when operation origin is not primary
             assert seqNo >= 0 : "recovery or replica ops should have an assigned seq no.; origin: " + origin;
         }
@@ -565,7 +565,7 @@ public class InternalEngine extends Engine {
     }
 
     private boolean assertSequenceNumberBeforeIndexing(final Engine.Operation.Origin origin, final long seqNo) {
-        if (engineConfig.getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED) ||
+        if (engineConfig.getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1) ||
             origin == Operation.Origin.PRIMARY) {
             // sequence number should be set when operation origin is primary or when all shards are on new nodes
             assert seqNo >= 0 : "ops should have an assigned seq no.; origin: " + origin;
@@ -679,7 +679,7 @@ public class InternalEngine extends Engine {
             } else {
                 // This can happen if the primary is still on an old node and send traffic without seq# or we recover from translog
                 // created by an old version.
-                assert config().getIndexSettings().getIndexVersionCreated().before(Version.V_6_0_0_alpha1_UNRELEASED) :
+                assert config().getIndexSettings().getIndexVersionCreated().before(Version.V_6_0_0_alpha1) :
                     "index is newly created but op has no sequence numbers. op: " + index;
                 opVsLucene = compareOpToLuceneDocBasedOnVersions(index);
             }
@@ -963,7 +963,7 @@ public class InternalEngine extends Engine {
         if (delete.seqNo() != SequenceNumbersService.UNASSIGNED_SEQ_NO) {
             opVsLucene = compareOpToLuceneDocBasedOnSeqNo(delete);
         } else {
-            assert config().getIndexSettings().getIndexVersionCreated().before(Version.V_6_0_0_alpha1_UNRELEASED) :
+            assert config().getIndexSettings().getIndexVersionCreated().before(Version.V_6_0_0_alpha1) :
                 "index is newly created but op has no sequence numbers. op: " + delete;
             opVsLucene = compareOpToLuceneDocBasedOnVersions(delete);
         }
diff --git a/core/src/main/java/org/elasticsearch/index/engine/Segment.java b/core/src/main/java/org/elasticsearch/index/engine/Segment.java
index 4de85d0020..b9df309970 100644
--- a/core/src/main/java/org/elasticsearch/index/engine/Segment.java
+++ b/core/src/main/java/org/elasticsearch/index/engine/Segment.java
@@ -168,7 +168,7 @@ public class Segment implements Streamable {
             // verbose mode
             ramTree = readRamTree(in);
         }
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             segmentSort = readSegmentSort(in);
         } else {
             segmentSort = null;
@@ -193,7 +193,7 @@ public class Segment implements Streamable {
         if (verbose) {
             writeRamTree(out, ramTree);
         }
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             writeSegmentSort(out, segmentSort);
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/AllFieldMapper.java b/core/src/main/java/org/elasticsearch/index/mapper/AllFieldMapper.java
index 85403ccc03..f3001db392 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/AllFieldMapper.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/AllFieldMapper.java
@@ -104,7 +104,7 @@ public class AllFieldMapper extends MetadataFieldMapper {
         public MetadataFieldMapper.Builder<?,?> parse(String name, Map<String, Object> node,
                                                  ParserContext parserContext) throws MapperParsingException {
             if (node.isEmpty() == false &&
-                    parserContext.indexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                    parserContext.indexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1)) {
                 throw new IllegalArgumentException("[_all] is disabled in 6.0. As a replacement, you can use an [copy_to] " +
                                 "on mapping fields to create your own catch all field.");
             }
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/BooleanFieldMapper.java b/core/src/main/java/org/elasticsearch/index/mapper/BooleanFieldMapper.java
index 7bd8c79ee6..93c8759d1d 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/BooleanFieldMapper.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/BooleanFieldMapper.java
@@ -233,7 +233,7 @@ public class BooleanFieldMapper extends FieldMapper {
                     value = fieldType().nullValue();
                 }
             } else {
-                if (indexCreatedVersion.onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                if (indexCreatedVersion.onOrAfter(Version.V_6_0_0_alpha1)) {
                     value = context.parser().booleanValue();
                 } else {
                     value = context.parser().booleanValueLenient();
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/DynamicTemplate.java b/core/src/main/java/org/elasticsearch/index/mapper/DynamicTemplate.java
index ca8fcd1ffd..0570cd7325 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/DynamicTemplate.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/DynamicTemplate.java
@@ -205,7 +205,7 @@ public class DynamicTemplate implements ToXContent {
             try {
                 xcontentFieldType = XContentFieldType.fromString(matchMappingType);
             } catch (IllegalArgumentException e) {
-                if (indexVersionCreated.onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                if (indexVersionCreated.onOrAfter(Version.V_6_0_0_alpha1)) {
                     throw e;
                 } else {
                     DEPRECATION_LOGGER.deprecated("match_mapping_type [" + matchMappingType + "] is invalid and will be ignored: "
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/MapperService.java b/core/src/main/java/org/elasticsearch/index/mapper/MapperService.java
index 4d68deef3b..50f424c268 100755
--- a/core/src/main/java/org/elasticsearch/index/mapper/MapperService.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/MapperService.java
@@ -102,7 +102,7 @@ public class MapperService extends AbstractIndexComponent implements Closeable {
         Function<Settings, String> defValue = settings -> {
             boolean singleType = true;
             if (settings.getAsVersion(IndexMetaData.SETTING_VERSION_CREATED, null) != null) {
-                singleType = Version.indexCreated(settings).onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED);
+                singleType = Version.indexCreated(settings).onOrAfter(Version.V_6_0_0_alpha1);
             }
             return Boolean.valueOf(singleType).toString();
         };
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/TypeParsers.java b/core/src/main/java/org/elasticsearch/index/mapper/TypeParsers.java
index 5b2ec6b2d9..1892824677 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/TypeParsers.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/TypeParsers.java
@@ -55,7 +55,7 @@ public class TypeParsers {
     //TODO 22298: Remove this method and have all call-sites use <code>XContentMapValues.nodeBooleanValue(node)</code> directly.
     public static boolean nodeBooleanValue(String fieldName, String propertyName, Object node,
                                            Mapper.TypeParser.ParserContext parserContext) {
-        if (parserContext.indexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (parserContext.indexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1)) {
             return XContentMapValues.nodeBooleanValue(node, fieldName + "." + propertyName);
         } else {
             return nodeBooleanValueLenient(fieldName, propertyName, node);
@@ -247,7 +247,7 @@ public class TypeParsers {
                 if (parserContext.isWithinMultiField()) {
                     throw new MapperParsingException("include_in_all in multi fields is not allowed. Found the include_in_all in field ["
                         + name + "] which is within a multi field.");
-                } else if (parserContext.indexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                } else if (parserContext.indexVersionCreated().onOrAfter(Version.V_6_0_0_alpha1)) {
                     throw new MapperParsingException("[include_in_all] is not allowed for indices created on or after version 6.0.0 as " +
                                     "[_all] is deprecated. As a replacement, you can use an [copy_to] on mapping fields to create your " +
                                     "own catch all field.");
diff --git a/core/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java b/core/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java
index c02ff4175c..cab2aee910 100644
--- a/core/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java
+++ b/core/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java
@@ -88,7 +88,7 @@ public class BoolQueryBuilder extends AbstractQueryBuilder<BoolQueryBuilder> {
         shouldClauses.addAll(readQueries(in));
         filterClauses.addAll(readQueries(in));
         adjustPureNegative = in.readBoolean();
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             in.readBoolean(); // disable_coord
         }
         minimumShouldMatch = in.readOptionalString();
@@ -101,7 +101,7 @@ public class BoolQueryBuilder extends AbstractQueryBuilder<BoolQueryBuilder> {
         writeQueries(out, shouldClauses);
         writeQueries(out, filterClauses);
         out.writeBoolean(adjustPureNegative);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             out.writeBoolean(true); // disable_coord
         }
         out.writeOptionalString(minimumShouldMatch);
diff --git a/core/src/main/java/org/elasticsearch/index/query/CommonTermsQueryBuilder.java b/core/src/main/java/org/elasticsearch/index/query/CommonTermsQueryBuilder.java
index e5fff943cd..63b09540a1 100644
--- a/core/src/main/java/org/elasticsearch/index/query/CommonTermsQueryBuilder.java
+++ b/core/src/main/java/org/elasticsearch/index/query/CommonTermsQueryBuilder.java
@@ -111,7 +111,7 @@ public class CommonTermsQueryBuilder extends AbstractQueryBuilder<CommonTermsQue
         analyzer = in.readOptionalString();
         lowFreqMinimumShouldMatch = in.readOptionalString();
         highFreqMinimumShouldMatch = in.readOptionalString();
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             in.readBoolean(); // disable_coord
         }
         cutoffFrequency = in.readFloat();
@@ -126,7 +126,7 @@ public class CommonTermsQueryBuilder extends AbstractQueryBuilder<CommonTermsQue
         out.writeOptionalString(analyzer);
         out.writeOptionalString(lowFreqMinimumShouldMatch);
         out.writeOptionalString(highFreqMinimumShouldMatch);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             out.writeBoolean(true); // disable_coord
         }
         out.writeFloat(cutoffFrequency);
diff --git a/core/src/main/java/org/elasticsearch/index/query/InnerHitBuilder.java b/core/src/main/java/org/elasticsearch/index/query/InnerHitBuilder.java
index fde98ee0d4..7b331dd487 100644
--- a/core/src/main/java/org/elasticsearch/index/query/InnerHitBuilder.java
+++ b/core/src/main/java/org/elasticsearch/index/query/InnerHitBuilder.java
@@ -126,7 +126,7 @@ public final class InnerHitBuilder extends ToXContentToBytes implements Writeabl
      */
     public InnerHitBuilder(StreamInput in) throws IOException {
         name = in.readOptionalString();
-        if (in.getVersion().before(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_5_5_0)) {
             in.readOptionalString();
             in.readOptionalString();
         }
@@ -156,7 +156,7 @@ public final class InnerHitBuilder extends ToXContentToBytes implements Writeabl
             }
         }
         highlightBuilder = in.readOptionalWriteable(HighlightBuilder::new);
-        if (in.getVersion().before(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_5_5_0)) {
             /**
              * this is needed for BWC with nodes pre 5.5
              */
@@ -168,8 +168,8 @@ public final class InnerHitBuilder extends ToXContentToBytes implements Writeabl
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        if (out.getVersion().before(Version.V_5_5_0_UNRELEASED)) {
-            throw new IOException("Invalid output version, must >= " + Version.V_5_5_0_UNRELEASED.toString());
+        if (out.getVersion().before(Version.V_5_5_0)) {
+            throw new IOException("Invalid output version, must >= " + Version.V_5_5_0.toString());
         }
         out.writeOptionalString(name);
         out.writeBoolean(ignoreUnmapped);
@@ -207,8 +207,8 @@ public final class InnerHitBuilder extends ToXContentToBytes implements Writeabl
      * Should only be used to send nested inner hits to nodes pre 5.5.
      */
     protected void writeToNestedBWC(StreamOutput out, QueryBuilder query, String nestedPath) throws IOException {
-        assert out.getVersion().before(Version.V_5_5_0_UNRELEASED) :
-            "invalid output version, must be < " + Version.V_5_5_0_UNRELEASED.toString();
+        assert out.getVersion().before(Version.V_5_5_0) :
+            "invalid output version, must be < " + Version.V_5_5_0.toString();
         writeToBWC(out, query, nestedPath, null);
     }
 
@@ -217,8 +217,8 @@ public final class InnerHitBuilder extends ToXContentToBytes implements Writeabl
      * Should only be used to send collapsing inner hits to nodes pre 5.5.
      */
     public void writeToCollapseBWC(StreamOutput out) throws IOException {
-        assert out.getVersion().before(Version.V_5_5_0_UNRELEASED) :
-            "invalid output version, must be < " + Version.V_5_5_0_UNRELEASED.toString();
+        assert out.getVersion().before(Version.V_5_5_0) :
+            "invalid output version, must be < " + Version.V_5_5_0.toString();
         writeToBWC(out, new MatchAllQueryBuilder(), null, null);
     }
 
@@ -227,8 +227,8 @@ public final class InnerHitBuilder extends ToXContentToBytes implements Writeabl
      * Should only be used to send hasParent or hasChild inner hits to nodes pre 5.5.
      */
     public void writeToParentChildBWC(StreamOutput out, QueryBuilder query, String parentChildPath) throws IOException {
-        assert(out.getVersion().before(Version.V_5_5_0_UNRELEASED)) :
-            "invalid output version, must be < " + Version.V_5_5_0_UNRELEASED.toString();
+        assert(out.getVersion().before(Version.V_5_5_0)) :
+            "invalid output version, must be < " + Version.V_5_5_0.toString();
         writeToBWC(out, query, null, parentChildPath);
     }
 
diff --git a/core/src/main/java/org/elasticsearch/index/query/NestedQueryBuilder.java b/core/src/main/java/org/elasticsearch/index/query/NestedQueryBuilder.java
index a62b95337f..ae092443f4 100644
--- a/core/src/main/java/org/elasticsearch/index/query/NestedQueryBuilder.java
+++ b/core/src/main/java/org/elasticsearch/index/query/NestedQueryBuilder.java
@@ -103,7 +103,7 @@ public class NestedQueryBuilder extends AbstractQueryBuilder<NestedQueryBuilder>
         out.writeString(path);
         out.writeVInt(scoreMode.ordinal());
         out.writeNamedWriteable(query);
-        if (out.getVersion().before(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_5_5_0)) {
             final boolean hasInnerHit = innerHitBuilder != null;
             out.writeBoolean(hasInnerHit);
             if (hasInnerHit) {
diff --git a/core/src/main/java/org/elasticsearch/index/seqno/GlobalCheckpointSyncAction.java b/core/src/main/java/org/elasticsearch/index/seqno/GlobalCheckpointSyncAction.java
index a55b920bb2..7baed972fc 100644
--- a/core/src/main/java/org/elasticsearch/index/seqno/GlobalCheckpointSyncAction.java
+++ b/core/src/main/java/org/elasticsearch/index/seqno/GlobalCheckpointSyncAction.java
@@ -86,7 +86,7 @@ public class GlobalCheckpointSyncAction extends TransportReplicationAction<
             final ConcreteReplicaRequest<Request> replicaRequest,
             final DiscoveryNode node,
             final ActionListener<ReplicationOperation.ReplicaResponse> listener) {
-        if (node.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (node.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             super.sendReplicaRequest(replicaRequest, node, listener);
         } else {
             listener.onResponse(new ReplicaResponse(replicaRequest.getTargetAllocationID(), SequenceNumbersService.UNASSIGNED_SEQ_NO));
diff --git a/core/src/main/java/org/elasticsearch/index/shard/IndexShard.java b/core/src/main/java/org/elasticsearch/index/shard/IndexShard.java
index 557b599666..35ab1db141 100644
--- a/core/src/main/java/org/elasticsearch/index/shard/IndexShard.java
+++ b/core/src/main/java/org/elasticsearch/index/shard/IndexShard.java
@@ -1092,7 +1092,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
 
     private boolean assertMaxUnsafeAutoIdInCommit() throws IOException {
         final Map<String, String> userData = SegmentInfos.readLatestCommit(store.directory()).getUserData();
-        if (indexSettings.getIndexVersionCreated().onOrAfter(Version.V_5_5_0_UNRELEASED) &&
+        if (indexSettings.getIndexVersionCreated().onOrAfter(Version.V_5_5_0) &&
             // TODO: LOCAL_SHARDS need to transfer this information
             recoveryState().getRecoverySource().getType() != RecoverySource.Type.LOCAL_SHARDS) {
             // as of 5.5.0, the engine stores the maxUnsafeAutoIdTimestamp in the commit point.
diff --git a/core/src/main/java/org/elasticsearch/index/store/StoreStats.java b/core/src/main/java/org/elasticsearch/index/store/StoreStats.java
index 422508d823..1ed7d6d01e 100644
--- a/core/src/main/java/org/elasticsearch/index/store/StoreStats.java
+++ b/core/src/main/java/org/elasticsearch/index/store/StoreStats.java
@@ -68,7 +68,7 @@ public class StoreStats implements Streamable, ToXContent {
     @Override
     public void readFrom(StreamInput in) throws IOException {
         sizeInBytes = in.readVLong();
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             in.readVLong(); // throttleTimeInNanos
         }
     }
@@ -76,7 +76,7 @@ public class StoreStats implements Streamable, ToXContent {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(sizeInBytes);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             out.writeVLong(0L); // throttleTimeInNanos
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java b/core/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java
index 147a952507..d230785a23 100644
--- a/core/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java
+++ b/core/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java
@@ -591,7 +591,7 @@ public class IndicesClusterStateService extends AbstractLifecycleComponent imple
             final DiscoveryNodes nodes) {
         return shardRoutings
                 .stream()
-                .filter(sr -> nodes.get(sr.currentNodeId()).getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED))
+                .filter(sr -> nodes.get(sr.currentNodeId()).getVersion().onOrAfter(Version.V_6_0_0_alpha1))
                 .map(ShardRouting::allocationId)
                 .map(AllocationId::getId)
                 .collect(Collectors.toSet());
diff --git a/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryFinalizeRecoveryRequest.java b/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryFinalizeRecoveryRequest.java
index eaace66107..2bdf45fede 100644
--- a/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryFinalizeRecoveryRequest.java
+++ b/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryFinalizeRecoveryRequest.java
@@ -60,7 +60,7 @@ public class RecoveryFinalizeRecoveryRequest extends TransportRequest {
         super.readFrom(in);
         recoveryId = in.readLong();
         shardId = ShardId.readShardId(in);
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             globalCheckpoint = in.readZLong();
         } else {
             globalCheckpoint = SequenceNumbersService.UNASSIGNED_SEQ_NO;
@@ -72,7 +72,7 @@ public class RecoveryFinalizeRecoveryRequest extends TransportRequest {
         super.writeTo(out);
         out.writeLong(recoveryId);
         shardId.writeTo(out);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeZLong(globalCheckpoint);
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryPrepareForTranslogOperationsRequest.java b/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryPrepareForTranslogOperationsRequest.java
index 155aa53e71..61cd986a1a 100644
--- a/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryPrepareForTranslogOperationsRequest.java
+++ b/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryPrepareForTranslogOperationsRequest.java
@@ -61,7 +61,7 @@ public class RecoveryPrepareForTranslogOperationsRequest extends TransportReques
         recoveryId = in.readLong();
         shardId = ShardId.readShardId(in);
         totalTranslogOps = in.readVInt();
-        if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             in.readLong(); // maxUnsafeAutoIdTimestamp
         }
     }
@@ -72,7 +72,7 @@ public class RecoveryPrepareForTranslogOperationsRequest extends TransportReques
         out.writeLong(recoveryId);
         shardId.writeTo(out);
         out.writeVInt(totalTranslogOps);
-        if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             out.writeLong(IndexRequest.UNSET_AUTO_GENERATED_TIMESTAMP); // maxUnsafeAutoIdTimestamp
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryTranslogOperationsResponse.java b/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryTranslogOperationsResponse.java
index 7427e631fb..731eb28ed9 100644
--- a/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryTranslogOperationsResponse.java
+++ b/core/src/main/java/org/elasticsearch/indices/recovery/RecoveryTranslogOperationsResponse.java
@@ -44,7 +44,7 @@ public class RecoveryTranslogOperationsResponse extends TransportResponse {
     @Override
     public void writeTo(final StreamOutput out) throws IOException {
         // before 6.0.0 we responded with an empty response so we have to maintain that
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeZLong(localCheckpoint);
         }
     }
@@ -52,7 +52,7 @@ public class RecoveryTranslogOperationsResponse extends TransportResponse {
     @Override
     public void readFrom(final StreamInput in) throws IOException {
         // before 6.0.0 we received an empty response so we have to maintain that
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             localCheckpoint = in.readZLong();
         }
         else {
diff --git a/core/src/main/java/org/elasticsearch/indices/recovery/StartRecoveryRequest.java b/core/src/main/java/org/elasticsearch/indices/recovery/StartRecoveryRequest.java
index a2a578cc72..825fa8306b 100644
--- a/core/src/main/java/org/elasticsearch/indices/recovery/StartRecoveryRequest.java
+++ b/core/src/main/java/org/elasticsearch/indices/recovery/StartRecoveryRequest.java
@@ -119,7 +119,7 @@ public class StartRecoveryRequest extends TransportRequest {
         targetNode = new DiscoveryNode(in);
         metadataSnapshot = new Store.MetadataSnapshot(in);
         primaryRelocation = in.readBoolean();
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             startingSeqNo = in.readLong();
         } else {
             startingSeqNo = SequenceNumbersService.UNASSIGNED_SEQ_NO;
@@ -136,7 +136,7 @@ public class StartRecoveryRequest extends TransportRequest {
         targetNode.writeTo(out);
         metadataSnapshot.writeTo(out);
         out.writeBoolean(primaryRelocation);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeLong(startingSeqNo);
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java b/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java
index 6f5e9a52b4..f2538365a7 100644
--- a/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java
+++ b/core/src/main/java/org/elasticsearch/monitor/fs/FsInfo.java
@@ -70,7 +70,7 @@ public class FsInfo implements Iterable<FsInfo.Path>, Writeable, ToXContent {
             total = in.readLong();
             free = in.readLong();
             available = in.readLong();
-            if (in.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
                 in.readOptionalBoolean();
             }
         }
@@ -83,7 +83,7 @@ public class FsInfo implements Iterable<FsInfo.Path>, Writeable, ToXContent {
             out.writeLong(total);
             out.writeLong(free);
             out.writeLong(available);
-            if (out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
                 out.writeOptionalBoolean(null);
             }
         }
@@ -455,7 +455,7 @@ public class FsInfo implements Iterable<FsInfo.Path>, Writeable, ToXContent {
             paths[i] = new Path(in);
         }
         this.total = total();
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             this.leastDiskEstimate = in.readOptionalWriteable(DiskUsage::new);
             this.mostDiskEstimate = in.readOptionalWriteable(DiskUsage::new);
         } else {
@@ -472,7 +472,7 @@ public class FsInfo implements Iterable<FsInfo.Path>, Writeable, ToXContent {
         for (Path path : paths) {
             path.writeTo(out);
         }
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
             out.writeOptionalWriteable(this.leastDiskEstimate);
             out.writeOptionalWriteable(this.mostDiskEstimate);
         }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/InternalOrder.java b/core/src/main/java/org/elasticsearch/search/aggregations/InternalOrder.java
index e81c0b1890..31594e2804 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/InternalOrder.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/InternalOrder.java
@@ -430,7 +430,7 @@ public class InternalOrder extends BucketOrder {
          * @throws IOException on error reading from the stream.
          */
         public static BucketOrder readHistogramOrder(StreamInput in, boolean bwcOrderFlag) throws IOException {
-            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha2_UNRELEASED)) {
+            if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha2)) {
                 return Streams.readOrder(in);
             } else { // backwards compat logic
                 if (bwcOrderFlag == false || in.readBoolean()) {
@@ -486,7 +486,7 @@ public class InternalOrder extends BucketOrder {
          * @throws IOException on error writing to the stream.
          */
         public static void writeHistogramOrder(BucketOrder order, StreamOutput out, boolean bwcOrderFlag) throws IOException {
-            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha2_UNRELEASED)) {
+            if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha2)) {
                 order.writeTo(out);
             } else { // backwards compat logic
                 if(bwcOrderFlag) { // need to add flag that determines if order exists
diff --git a/core/src/main/java/org/elasticsearch/search/collapse/CollapseBuilder.java b/core/src/main/java/org/elasticsearch/search/collapse/CollapseBuilder.java
index df8808f447..93f4b8bf41 100644
--- a/core/src/main/java/org/elasticsearch/search/collapse/CollapseBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/collapse/CollapseBuilder.java
@@ -95,7 +95,7 @@ public class CollapseBuilder implements Writeable, ToXContentObject {
     public CollapseBuilder(StreamInput in) throws IOException {
         this.field = in.readString();
         this.maxConcurrentGroupRequests = in.readVInt();
-        if (in.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_5_5_0)) {
             this.innerHits = in.readList(InnerHitBuilder::new);
         } else {
             InnerHitBuilder innerHitBuilder = in.readOptionalWriteable(InnerHitBuilder::new);
@@ -111,7 +111,7 @@ public class CollapseBuilder implements Writeable, ToXContentObject {
     public void writeTo(StreamOutput out) throws IOException {
         out.writeString(field);
         out.writeVInt(maxConcurrentGroupRequests);
-        if (out.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_5_5_0)) {
             out.writeList(innerHits);
         } else {
             boolean hasInnerHit = innerHits.isEmpty() == false;
diff --git a/core/src/main/java/org/elasticsearch/snapshots/SnapshotInfo.java b/core/src/main/java/org/elasticsearch/snapshots/SnapshotInfo.java
index 37cce0ac60..a54e72159f 100644
--- a/core/src/main/java/org/elasticsearch/snapshots/SnapshotInfo.java
+++ b/core/src/main/java/org/elasticsearch/snapshots/SnapshotInfo.java
@@ -70,7 +70,7 @@ public final class SnapshotInfo implements Comparable<SnapshotInfo>, ToXContent,
     private static final String SUCCESSFUL_SHARDS = "successful_shards";
 
     private static final Version VERSION_INCOMPATIBLE_INTRODUCED = Version.V_5_2_0;
-    public static final Version VERBOSE_INTRODUCED = Version.V_5_5_0_UNRELEASED;
+    public static final Version VERBOSE_INTRODUCED = Version.V_5_5_0;
 
     private static final Comparator<SnapshotInfo> COMPARATOR =
         Comparator.comparing(SnapshotInfo::startTime).thenComparing(SnapshotInfo::snapshotId);
diff --git a/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java b/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
index 7b0c4eb752..b61da9c27f 100644
--- a/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
+++ b/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
@@ -612,7 +612,7 @@ public class ThreadPool extends AbstractComponent implements Closeable {
         public void writeTo(StreamOutput out) throws IOException {
             out.writeString(name);
             if (type == ThreadPoolType.FIXED_AUTO_QUEUE_SIZE &&
-                    out.getVersion().before(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                    out.getVersion().before(Version.V_6_0_0_alpha1)) {
                 // 5.x doesn't know about the "fixed_auto_queue_size" thread pool type, just write fixed.
                 out.writeString(ThreadPoolType.FIXED.getType());
             } else {
diff --git a/core/src/test/java/org/elasticsearch/VersionTests.java b/core/src/test/java/org/elasticsearch/VersionTests.java
index 27782511de..3bdec11472 100644
--- a/core/src/test/java/org/elasticsearch/VersionTests.java
+++ b/core/src/test/java/org/elasticsearch/VersionTests.java
@@ -34,7 +34,7 @@ import java.util.Map;
 import java.util.Set;
 
 import static org.elasticsearch.Version.V_5_3_0;
-import static org.elasticsearch.Version.V_6_0_0_alpha2_UNRELEASED;
+import static org.elasticsearch.Version.V_6_0_0_alpha2;
 import static org.elasticsearch.test.VersionUtils.randomVersion;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.Matchers.containsString;
@@ -46,30 +46,30 @@ import static org.hamcrest.Matchers.sameInstance;
 public class VersionTests extends ESTestCase {
 
     public void testVersionComparison() throws Exception {
-        assertThat(V_5_3_0.before(V_6_0_0_alpha2_UNRELEASED), is(true));
+        assertThat(V_5_3_0.before(V_6_0_0_alpha2), is(true));
         assertThat(V_5_3_0.before(V_5_3_0), is(false));
-        assertThat(V_6_0_0_alpha2_UNRELEASED.before(V_5_3_0), is(false));
+        assertThat(V_6_0_0_alpha2.before(V_5_3_0), is(false));
 
-        assertThat(V_5_3_0.onOrBefore(V_6_0_0_alpha2_UNRELEASED), is(true));
+        assertThat(V_5_3_0.onOrBefore(V_6_0_0_alpha2), is(true));
         assertThat(V_5_3_0.onOrBefore(V_5_3_0), is(true));
-        assertThat(V_6_0_0_alpha2_UNRELEASED.onOrBefore(V_5_3_0), is(false));
+        assertThat(V_6_0_0_alpha2.onOrBefore(V_5_3_0), is(false));
 
-        assertThat(V_5_3_0.after(V_6_0_0_alpha2_UNRELEASED), is(false));
+        assertThat(V_5_3_0.after(V_6_0_0_alpha2), is(false));
         assertThat(V_5_3_0.after(V_5_3_0), is(false));
-        assertThat(V_6_0_0_alpha2_UNRELEASED.after(V_5_3_0), is(true));
+        assertThat(V_6_0_0_alpha2.after(V_5_3_0), is(true));
 
-        assertThat(V_5_3_0.onOrAfter(V_6_0_0_alpha2_UNRELEASED), is(false));
+        assertThat(V_5_3_0.onOrAfter(V_6_0_0_alpha2), is(false));
         assertThat(V_5_3_0.onOrAfter(V_5_3_0), is(true));
-        assertThat(V_6_0_0_alpha2_UNRELEASED.onOrAfter(V_5_3_0), is(true));
+        assertThat(V_6_0_0_alpha2.onOrAfter(V_5_3_0), is(true));
 
         assertTrue(Version.fromString("5.0.0-alpha2").onOrAfter(Version.fromString("5.0.0-alpha1")));
         assertTrue(Version.fromString("5.0.0").onOrAfter(Version.fromString("5.0.0-beta2")));
         assertTrue(Version.fromString("5.0.0-rc1").onOrAfter(Version.fromString("5.0.0-beta24")));
         assertTrue(Version.fromString("5.0.0-alpha24").before(Version.fromString("5.0.0-beta0")));
 
-        assertThat(V_5_3_0, is(lessThan(V_6_0_0_alpha2_UNRELEASED)));
+        assertThat(V_5_3_0, is(lessThan(V_6_0_0_alpha2)));
         assertThat(V_5_3_0.compareTo(V_5_3_0), is(0));
-        assertThat(V_6_0_0_alpha2_UNRELEASED, is(greaterThan(V_5_3_0)));
+        assertThat(V_6_0_0_alpha2, is(greaterThan(V_5_3_0)));
     }
 
     public void testMin() {
@@ -97,7 +97,7 @@ public class VersionTests extends ESTestCase {
     }
 
     public void testMinimumIndexCompatibilityVersion() {
-        assertEquals(Version.V_5_0_0, Version.V_6_0_0_alpha2_UNRELEASED.minimumIndexCompatibilityVersion());
+        assertEquals(Version.V_5_0_0, Version.V_6_0_0_alpha2.minimumIndexCompatibilityVersion());
         assertEquals(Version.fromId(2000099), Version.V_5_0_0.minimumIndexCompatibilityVersion());
         assertEquals(Version.fromId(2000099),
                 Version.V_5_1_1.minimumIndexCompatibilityVersion());
@@ -157,7 +157,7 @@ public class VersionTests extends ESTestCase {
     public void testIndexCreatedVersion() {
         // an actual index has a IndexMetaData.SETTING_INDEX_UUID
         final Version version = randomFrom(Version.V_5_0_0, Version.V_5_0_2,
-                Version.V_5_2_0, Version.V_6_0_0_alpha2_UNRELEASED);
+                Version.V_5_2_0, Version.V_6_0_0_alpha2);
         assertEquals(version, Version.indexCreated(Settings.builder().put(IndexMetaData.SETTING_INDEX_UUID, "foo").put(IndexMetaData.SETTING_VERSION_CREATED, version).build()));
     }
 
@@ -170,11 +170,11 @@ public class VersionTests extends ESTestCase {
         assertThat(Version.fromString("2.3.0").minimumCompatibilityVersion(), equalTo(major));
         // from 6.0 on we are supporting the latest minor of the previous major... this might fail once we add a new version ie. 5.x is
         // released since we need to bump the supported minor in Version#minimumCompatibilityVersion()
-        Version lastVersion = VersionUtils.getPreviousVersion(Version.V_6_0_0_alpha2_UNRELEASED);
-        assertEquals(lastVersion.major, Version.V_6_0_0_alpha2_UNRELEASED.minimumCompatibilityVersion().major);
+        Version lastVersion = VersionUtils.getPreviousVersion(Version.V_6_0_0_alpha1);
+        assertEquals(lastVersion.major, Version.V_6_0_0_alpha2.minimumCompatibilityVersion().major);
         assertEquals("did you miss to bump the minor in Version#minimumCompatibilityVersion()",
-                lastVersion.minor, Version.V_6_0_0_alpha2_UNRELEASED.minimumCompatibilityVersion().minor);
-        assertEquals(0, Version.V_6_0_0_alpha2_UNRELEASED.minimumCompatibilityVersion().revision);
+                lastVersion.minor, Version.V_6_0_0_alpha2.minimumCompatibilityVersion().minor);
+        assertEquals(0, Version.V_6_0_0_alpha2.minimumCompatibilityVersion().revision);
     }
 
     public void testToString() {
@@ -325,8 +325,8 @@ public class VersionTests extends ESTestCase {
 
     public void testIsCompatible() {
         assertTrue(isCompatible(Version.CURRENT, Version.CURRENT.minimumCompatibilityVersion()));
-        assertTrue(isCompatible(Version.V_5_5_0_UNRELEASED, Version.V_6_0_0_alpha2_UNRELEASED));
-        assertFalse(isCompatible(Version.fromId(2000099), Version.V_6_0_0_alpha2_UNRELEASED));
+        assertTrue(isCompatible(Version.V_5_5_0, Version.V_6_0_0_alpha2));
+        assertFalse(isCompatible(Version.fromId(2000099), Version.V_6_0_0_alpha2));
         assertFalse(isCompatible(Version.fromId(2000099), Version.V_5_0_0));
         assertTrue(isCompatible(Version.fromString("6.0.0"), Version.fromString("7.0.0")));
         if (Version.CURRENT.isRelease()) {
diff --git a/core/src/test/java/org/elasticsearch/common/settings/SettingsTests.java b/core/src/test/java/org/elasticsearch/common/settings/SettingsTests.java
index 6eec34a90e..80ca8cc275 100644
--- a/core/src/test/java/org/elasticsearch/common/settings/SettingsTests.java
+++ b/core/src/test/java/org/elasticsearch/common/settings/SettingsTests.java
@@ -155,7 +155,7 @@ public class SettingsTests extends ESTestCase {
         // time to say goodbye?
         assertTrue(
             "It's time to implement #22298. Please delete this test and Settings#getAsBooleanLenientForPreEs6Indices().",
-            Version.CURRENT.minimumCompatibilityVersion().before(Version.V_6_0_0_alpha1_UNRELEASED));
+            Version.CURRENT.minimumCompatibilityVersion().before(Version.V_6_0_0_alpha1));
 
 
         String falsy = randomFrom("false", "off", "no", "0");
diff --git a/core/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java b/core/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java
index 9f4a33ada6..8bf948240b 100644
--- a/core/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java
+++ b/core/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java
@@ -2578,7 +2578,7 @@ public class InternalEngineTests extends ESTestCase {
                 for (int i = 0; i < numExtraDocs; i++) {
                     ParsedDocument doc = testParsedDocument("extra" + Integer.toString(i), null, testDocument(), new BytesArray("{}"), null);
                     Term uid;
-                    if (indexMetaData.getCreationVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                    if (indexMetaData.getCreationVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                         uid = new Term(IdFieldMapper.NAME, doc.id());
                     } else {
                         uid = new Term(UidFieldMapper.NAME, Uid.createUid(doc.type(), doc.id()));
diff --git a/core/src/test/java/org/elasticsearch/index/mapper/DynamicTemplateTests.java b/core/src/test/java/org/elasticsearch/index/mapper/DynamicTemplateTests.java
index ffc921d013..7ed6efe516 100644
--- a/core/src/test/java/org/elasticsearch/index/mapper/DynamicTemplateTests.java
+++ b/core/src/test/java/org/elasticsearch/index/mapper/DynamicTemplateTests.java
@@ -56,7 +56,7 @@ public class DynamicTemplateTests extends ESTestCase {
         templateDef2.put("mapping", Collections.singletonMap("store", true));
         // if a wrong match type is specified, we ignore the template
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class,
-                () -> DynamicTemplate.parse("my_template", templateDef2, Version.V_6_0_0_alpha1_UNRELEASED));
+                () -> DynamicTemplate.parse("my_template", templateDef2, Version.V_6_0_0_alpha1));
         assertEquals("No field type matched on [text], possible values are [object, string, long, double, boolean, date, binary]",
                 e.getMessage());
     }
diff --git a/core/src/test/java/org/elasticsearch/indices/recovery/StartRecoveryRequestTests.java b/core/src/test/java/org/elasticsearch/indices/recovery/StartRecoveryRequestTests.java
index 6981ebdae4..58c2fa6277 100644
--- a/core/src/test/java/org/elasticsearch/indices/recovery/StartRecoveryRequestTests.java
+++ b/core/src/test/java/org/elasticsearch/indices/recovery/StartRecoveryRequestTests.java
@@ -71,7 +71,7 @@ public class StartRecoveryRequestTests extends ESTestCase {
         assertThat(outRequest.metadataSnapshot().asMap(), equalTo(inRequest.metadataSnapshot().asMap()));
         assertThat(outRequest.isPrimaryRelocation(), equalTo(inRequest.isPrimaryRelocation()));
         assertThat(outRequest.recoveryId(), equalTo(inRequest.recoveryId()));
-        if (targetNodeVersion.onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+        if (targetNodeVersion.onOrAfter(Version.V_6_0_0_alpha1)) {
             assertThat(outRequest.startingSeqNo(), equalTo(inRequest.startingSeqNo()));
         } else {
             assertThat(SequenceNumbersService.UNASSIGNED_SEQ_NO, equalTo(inRequest.startingSeqNo()));
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/InternalOrderTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/InternalOrderTests.java
index 43d10af99f..d26eeca387 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/InternalOrderTests.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/InternalOrderTests.java
@@ -110,7 +110,7 @@ public class InternalOrderTests extends AbstractSerializingTestCase<BucketOrder>
         for (int runs = 0; runs < NUMBER_OF_TEST_RUNS; runs++) {
             BucketOrder order = createTestInstance();
             Version bwcVersion = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(),
-                VersionUtils.getPreviousVersion(Version.V_6_0_0_alpha2_UNRELEASED));
+                VersionUtils.getPreviousVersion(Version.V_6_0_0_alpha2));
             boolean bwcOrderFlag = randomBoolean();
             try (BytesStreamOutput out = new BytesStreamOutput()) {
                 out.setVersion(bwcVersion);
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MultiSearchTemplateRequest.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MultiSearchTemplateRequest.java
index fceb6fb98d..bd294db6d2 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MultiSearchTemplateRequest.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MultiSearchTemplateRequest.java
@@ -112,7 +112,7 @@ public class MultiSearchTemplateRequest extends ActionRequest implements Composi
     @Override
     public void readFrom(StreamInput in) throws IOException {
         super.readFrom(in);
-        if (in.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (in.getVersion().onOrAfter(Version.V_5_5_0)) {
             maxConcurrentSearchRequests = in.readVInt();
         }
         requests = in.readStreamableList(SearchTemplateRequest::new);
@@ -121,7 +121,7 @@ public class MultiSearchTemplateRequest extends ActionRequest implements Composi
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
-        if (out.getVersion().onOrAfter(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().onOrAfter(Version.V_5_5_0)) {
             out.writeVInt(maxConcurrentSearchRequests);
         }
         out.writeStreamableList(requests);
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java
index 50fb925de6..f574236b35 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java
@@ -126,7 +126,7 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
         out.writeInt(maxChildren);
         out.writeVInt(scoreMode.ordinal());
         out.writeNamedWriteable(query);
-        if (out.getVersion().before(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_5_5_0)) {
             final boolean hasInnerHit = innerHitBuilder != null;
             out.writeBoolean(hasInnerHit);
             if (hasInnerHit) {
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java
index 559f5530c3..7bcbf7c611 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java
@@ -121,7 +121,7 @@ public class HasParentQueryBuilder extends AbstractQueryBuilder<HasParentQueryBu
         out.writeString(type);
         out.writeBoolean(score);
         out.writeNamedWriteable(query);
-        if (out.getVersion().before(Version.V_5_5_0_UNRELEASED)) {
+        if (out.getVersion().before(Version.V_5_5_0)) {
             final boolean hasInnerHit = innerHitBuilder != null;
             out.writeBoolean(hasInnerHit);
             if (hasInnerHit) {
diff --git a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
index 0b4bf3f253..93c544f265 100644
--- a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
+++ b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
@@ -52,7 +52,7 @@ public class FullClusterRestartIT extends ESRestTestCase {
 
     private final boolean runningAgainstOldCluster = Booleans.parseBoolean(System.getProperty("tests.is_old_cluster"));
     private final Version oldClusterVersion = Version.fromString(System.getProperty("tests.old_cluster_version"));
-    private final boolean supportsLenientBooleans = oldClusterVersion.onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED);
+    private final boolean supportsLenientBooleans = oldClusterVersion.onOrAfter(Version.V_6_0_0_alpha1);
 
     @Override
     protected boolean preserveIndicesUponCompletion() {
diff --git a/qa/mixed-cluster/src/test/java/org/elasticsearch/backwards/IndexingIT.java b/qa/mixed-cluster/src/test/java/org/elasticsearch/backwards/IndexingIT.java
index 0954682094..1216b25178 100644
--- a/qa/mixed-cluster/src/test/java/org/elasticsearch/backwards/IndexingIT.java
+++ b/qa/mixed-cluster/src/test/java/org/elasticsearch/backwards/IndexingIT.java
@@ -207,7 +207,7 @@ public class IndexingIT extends ESRestTestCase {
             .put(IndexMetaData.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 2)
             .put("index.routing.allocation.include._name", bwcNames);
 
-        final boolean checkGlobalCheckpoints = nodes.getMaster().getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED);
+        final boolean checkGlobalCheckpoints = nodes.getMaster().getVersion().onOrAfter(Version.V_6_0_0_alpha1);
         logger.info("master version is [{}], global checkpoints will be [{}]", nodes.getMaster().getVersion(),
             checkGlobalCheckpoints ? "checked" : "not be checked");
         final String index = "test";
@@ -287,7 +287,7 @@ public class IndexingIT extends ESRestTestCase {
                 final long expectedGlobalCkp;
                 final long expectMaxSeqNo;
                 logger.info("primary resolved to node {}", primaryShard.getNode());
-                if (primaryShard.getNode().getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                if (primaryShard.getNode().getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                     expectMaxSeqNo = numDocs - 1;
                     expectedGlobalCkp = numDocs - 1;
                 } else {
@@ -295,7 +295,7 @@ public class IndexingIT extends ESRestTestCase {
                     expectMaxSeqNo = SequenceNumbersService.NO_OPS_PERFORMED;
                 }
                 for (Shard shard : shards) {
-                    if (shard.getNode().getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+                    if (shard.getNode().getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                         final SeqNoStats seqNoStats = shard.getSeqNoStats();
                         logger.info("stats for {}, primary [{}]: [{}]", shard.getNode(), shard.isPrimary(), seqNoStats);
                         assertThat("max_seq no on " + shard.getNode() + " is wrong", seqNoStats.getMaxSeqNo(), equalTo(expectMaxSeqNo));
@@ -324,7 +324,7 @@ public class IndexingIT extends ESRestTestCase {
             final Boolean primary = ObjectPath.evaluate(shard, "routing.primary");
             final Node node = nodes.getSafe(nodeId);
             final SeqNoStats seqNoStats;
-            if (node.getVersion().onOrAfter(Version.V_6_0_0_alpha1_UNRELEASED)) {
+            if (node.getVersion().onOrAfter(Version.V_6_0_0_alpha1)) {
                 Integer maxSeqNo = ObjectPath.evaluate(shard, "seq_no.max_seq_no");
                 Integer localCheckpoint = ObjectPath.evaluate(shard, "seq_no.local_checkpoint");
                 Integer globalCheckpoint = ObjectPath.evaluate(shard, "seq_no.global_checkpoint");
diff --git a/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java b/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java
index 5d8af02a06..9f93a63919 100644
--- a/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java
+++ b/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java
@@ -20,60 +20,101 @@
 package org.elasticsearch.test;
 
 import org.elasticsearch.Version;
+import org.elasticsearch.common.collect.Tuple;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Random;
-import java.util.Set;
-import java.util.stream.Collectors;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+import static java.util.Collections.unmodifiableList;
 
 /** Utilities for selecting versions in tests */
 public class VersionUtils {
-
-    private static final List<Version> RELEASED_VERSIONS;
-    private static final List<Version> UNRELEASED_VERSIONS;
-
-    static {
-        final Field[] declaredFields = Version.class.getFields();
-        final Set<Integer> releasedIdsSet = new HashSet<>();
-        final Set<Integer> unreleasedIdsSet = new HashSet<>();
-        for (final Field field : declaredFields) {
+    /**
+     * Sort versions that have backwards compatibility guarantees from
+     * those that don't. Doesn't actually check whether or not the versions
+     * are released, instead it relies on gradle to have already checked
+     * this which it does in {@code :core:verifyVersions}. So long as the
+     * rules here match up with the rules in gradle then this should
+     * produce sensible results.
+     * @return a tuple containing versions with backwards compatibility
+     * guarantees in v1 and versions without the guranteees in v2
+     */
+    static Tuple<List<Version>, List<Version>> resolveReleasedVersions(Version current, Class<?> versionClass) {
+        Field[] fields = versionClass.getFields();
+        List<Version> versions = new ArrayList<>(fields.length);
+        for (final Field field : fields) {
             final int mod = field.getModifiers();
-            if (Modifier.isStatic(mod) && Modifier.isFinal(mod) && Modifier.isPublic(mod)) {
-                if (field.getType() == Version.class) {
-                    final int id;
-                    try {
-                        id = ((Version) field.get(null)).id;
-                    } catch (final IllegalAccessException e) {
-                        throw new RuntimeException(e);
-                    }
-                    assert field.getName().matches("(V(_\\d+)+(_(alpha|beta|rc)\\d+)?(_UNRELEASED)?|CURRENT)") : field.getName();
-                    // note that below we remove CURRENT and add it to released; we do it this way because there are two constants that
-                    // correspond to CURRENT, CURRENT itself and the actual version that CURRENT points to
-                    if (field.getName().equals("CURRENT") || field.getName().endsWith("UNRELEASED")) {
-                        unreleasedIdsSet.add(id);
-                    } else {
-                        releasedIdsSet.add(id);
-                    }
-                }
+            if (false == Modifier.isStatic(mod) && Modifier.isFinal(mod) && Modifier.isPublic(mod)) {
+                continue;
+            }
+            if (field.getType() != Version.class) {
+                continue;
+            }
+            assert field.getName().matches("(V(_\\d+)+(_(alpha|beta|rc)\\d+)?|CURRENT)") : field.getName();
+            if ("CURRENT".equals(field.getName())) {
+                continue;
+            }
+            try {
+                versions.add(((Version) field.get(null)));
+            } catch (final IllegalAccessException e) {
+                throw new RuntimeException(e);
             }
         }
+        Collections.sort(versions);
+        assert versions.get(versions.size() - 1).equals(current) : "The highest version must be the current one "
+            + "but was [" + versions.get(versions.size() - 1) + "] and current was [" + current + "]";
+
+        if (current.revision != 0) {
+            /* If we are in a stable branch there should be no unreleased version constants
+             * because we don't expect to release any new versions in older branches. If there
+             * are extra constants then gradle will yell about it. */
+            return new Tuple<>(unmodifiableList(versions), emptyList());
+        }
+
+        /* If we are on a patch release then we know that at least the version before the
+         * current one is unreleased. If it is released then gradle would be complaining. */
+        int unreleasedIndex = versions.size() - 2;
+        while (true) {
+            if (unreleasedIndex < 0) {
+                throw new IllegalArgumentException("Couldn't find first non-alpha release");
+            }
+            /* Technically we don't support backwards compatiblity for alphas, betas,
+             * and rcs. But the testing infrastructure requires that we act as though we
+             * do. This is a difference between the gradle and Java logic but should be
+             * fairly safe as it is errs on us being more compatible rather than less....
+             * Anyway, the upshot is that we never declare alphas as unreleased, no
+             * matter where they are in the list. */
+            if (versions.get(unreleasedIndex).isRelease()) {
+                break;
+            }
+            unreleasedIndex--;
+        }
 
-        // treat CURRENT as released for BWC testing
-        unreleasedIdsSet.remove(Version.CURRENT.id);
-        releasedIdsSet.add(Version.CURRENT.id);
+        Version unreleased = versions.remove(unreleasedIndex);
+        if (unreleased.revision == 0) {
+            /* If the last unreleased version is itself a patch release then gradle enforces
+             * that there is yet another unreleased version before that. */
+            unreleasedIndex--;
+            Version earlierUnreleased = versions.remove(unreleasedIndex);
+            return new Tuple<>(unmodifiableList(versions), unmodifiableList(Arrays.asList(earlierUnreleased, unreleased)));
+        }
+        return new Tuple<>(unmodifiableList(versions), singletonList(unreleased));
+    }
 
-        // unreleasedIdsSet and releasedIdsSet should be disjoint
-        assert unreleasedIdsSet.stream().filter(releasedIdsSet::contains).collect(Collectors.toSet()).isEmpty();
+    private static final List<Version> RELEASED_VERSIONS;
+    private static final List<Version> UNRELEASED_VERSIONS;
 
-        RELEASED_VERSIONS =
-            Collections.unmodifiableList(releasedIdsSet.stream().sorted().map(Version::fromId).collect(Collectors.toList()));
-        UNRELEASED_VERSIONS =
-            Collections.unmodifiableList(unreleasedIdsSet.stream().sorted().map(Version::fromId).collect(Collectors.toList()));
+    static {
+        Tuple<List<Version>, List<Version>> versions = resolveReleasedVersions(Version.CURRENT, Version.class);
+        RELEASED_VERSIONS = versions.v1();
+        UNRELEASED_VERSIONS = versions.v2();
     }
 
     /**
diff --git a/test/framework/src/test/java/org/elasticsearch/test/VersionUtilsTests.java b/test/framework/src/test/java/org/elasticsearch/test/VersionUtilsTests.java
new file mode 100644
index 0000000000..4b59abc0a3
--- /dev/null
+++ b/test/framework/src/test/java/org/elasticsearch/test/VersionUtilsTests.java
@@ -0,0 +1,162 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.elasticsearch.test;
+
+import org.elasticsearch.Version;
+import org.elasticsearch.common.collect.Tuple;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+
+public class VersionUtilsTests extends ESTestCase {
+
+    public void testAllVersionsSorted() {
+        List<Version> allVersions = VersionUtils.allReleasedVersions();
+        for (int i = 0, j = 1; j < allVersions.size(); ++i, ++j) {
+            assertTrue(allVersions.get(i).before(allVersions.get(j)));
+        }
+    }
+
+    public void testRandomVersionBetween() {
+        // full range
+        Version got = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(), Version.CURRENT);
+        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
+        assertTrue(got.onOrBefore(Version.CURRENT));
+        got = VersionUtils.randomVersionBetween(random(), null, Version.CURRENT);
+        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
+        assertTrue(got.onOrBefore(Version.CURRENT));
+        got = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(), null);
+        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
+        assertTrue(got.onOrBefore(Version.CURRENT));
+
+        // sub range
+        got = VersionUtils.randomVersionBetween(random(), Version.V_5_0_0,
+                Version.V_6_0_0_alpha2);
+        assertTrue(got.onOrAfter(Version.V_5_0_0));
+        assertTrue(got.onOrBefore(Version.V_6_0_0_alpha2));
+
+        // unbounded lower
+        got = VersionUtils.randomVersionBetween(random(), null, Version.V_6_0_0_alpha2);
+        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
+        assertTrue(got.onOrBefore(Version.V_6_0_0_alpha2));
+        got = VersionUtils.randomVersionBetween(random(), null, VersionUtils.allReleasedVersions().get(0));
+        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
+        assertTrue(got.onOrBefore(VersionUtils.allReleasedVersions().get(0)));
+
+        // unbounded upper
+        got = VersionUtils.randomVersionBetween(random(), Version.V_5_0_0, null);
+        assertTrue(got.onOrAfter(Version.V_5_0_0));
+        assertTrue(got.onOrBefore(Version.CURRENT));
+        got = VersionUtils.randomVersionBetween(random(), VersionUtils.getPreviousVersion(), null);
+        assertTrue(got.onOrAfter(VersionUtils.getPreviousVersion()));
+        assertTrue(got.onOrBefore(Version.CURRENT));
+
+        // range of one
+        got = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(), VersionUtils.getFirstVersion());
+        assertEquals(got, VersionUtils.getFirstVersion());
+        got = VersionUtils.randomVersionBetween(random(), Version.CURRENT, Version.CURRENT);
+        assertEquals(got, Version.CURRENT);
+        got = VersionUtils.randomVersionBetween(random(), Version.V_6_0_0_alpha2,
+                Version.V_6_0_0_alpha2);
+        assertEquals(got, Version.V_6_0_0_alpha2);
+
+        // implicit range of one
+        got = VersionUtils.randomVersionBetween(random(), null, VersionUtils.getFirstVersion());
+        assertEquals(got, VersionUtils.getFirstVersion());
+        got = VersionUtils.randomVersionBetween(random(), Version.CURRENT, null);
+        assertEquals(got, Version.CURRENT);
+    }
+
+    static class TestReleaseBranch {
+        public static final Version V_5_3_0 = Version.fromString("5.3.0");
+        public static final Version V_5_3_1 = Version.fromString("5.3.1");
+        public static final Version V_5_3_2 = Version.fromString("5.3.2");
+        public static final Version V_5_4_0 = Version.fromString("5.4.0");
+        public static final Version V_5_4_1 = Version.fromString("5.4.1");
+        public static final Version CURRENT = V_5_4_1;
+    }
+    public void testResolveReleasedVersionsForReleaseBranch() {
+        Tuple<List<Version>, List<Version>> t = VersionUtils.resolveReleasedVersions(TestReleaseBranch.CURRENT, TestReleaseBranch.class);
+        List<Version> released = t.v1();
+        List<Version> unreleased = t.v2();
+        assertEquals(Arrays.asList(TestReleaseBranch.V_5_3_0, TestReleaseBranch.V_5_3_1, TestReleaseBranch.V_5_3_2,
+                TestReleaseBranch.V_5_4_0, TestReleaseBranch.V_5_4_1), released);
+        assertEquals(emptyList(), unreleased);
+    }
+
+    static class TestStableBranch {
+        public static final Version V_5_3_0 = Version.fromString("5.3.0");
+        public static final Version V_5_3_1 = Version.fromString("5.3.1");
+        public static final Version V_5_3_2 = Version.fromString("5.3.2");
+        public static final Version V_5_4_0 = Version.fromString("5.4.0");
+        public static final Version CURRENT = V_5_4_0;
+    }
+    public void testResolveReleasedVersionsForUnreleasedStableBranch() {
+        Tuple<List<Version>, List<Version>> t = VersionUtils.resolveReleasedVersions(TestStableBranch.CURRENT,
+                TestStableBranch.class);
+        List<Version> released = t.v1();
+        List<Version> unreleased = t.v2();
+        assertEquals(
+                Arrays.asList(TestStableBranch.V_5_3_0, TestStableBranch.V_5_3_1, TestStableBranch.V_5_4_0),
+                released);
+        assertEquals(singletonList(TestStableBranch.V_5_3_2), unreleased);
+    }
+
+    static class TestStableBranchBehindStableBranch {
+        public static final Version V_5_3_0 = Version.fromString("5.3.0");
+        public static final Version V_5_3_1 = Version.fromString("5.3.1");
+        public static final Version V_5_3_2 = Version.fromString("5.3.2");
+        public static final Version V_5_4_0 = Version.fromString("5.4.0");
+        public static final Version V_5_5_0 = Version.fromString("5.5.0");
+        public static final Version CURRENT = V_5_5_0;
+    }
+    public void testResolveReleasedVersionsForStableBtranchBehindStableBranch() {
+        Tuple<List<Version>, List<Version>> t = VersionUtils.resolveReleasedVersions(TestStableBranchBehindStableBranch.CURRENT,
+                TestStableBranchBehindStableBranch.class);
+        List<Version> released = t.v1();
+        List<Version> unreleased = t.v2();
+        assertEquals(Arrays.asList(TestStableBranchBehindStableBranch.V_5_3_0, TestStableBranchBehindStableBranch.V_5_3_1,
+                TestStableBranchBehindStableBranch.V_5_5_0), released);
+        assertEquals(Arrays.asList(TestStableBranchBehindStableBranch.V_5_3_2, Version.V_5_4_0), unreleased);
+    }
+
+    static class TestUnstableBranch {
+        public static final Version V_5_3_0 = Version.fromString("5.3.0");
+        public static final Version V_5_3_1 = Version.fromString("5.3.1");
+        public static final Version V_5_3_2 = Version.fromString("5.3.2");
+        public static final Version V_5_4_0 = Version.fromString("5.4.0");
+        public static final Version V_6_0_0_alpha1 = Version.fromString("6.0.0-alpha1");
+        public static final Version V_6_0_0_alpha2 = Version.fromString("6.0.0-alpha2");
+        public static final Version CURRENT = V_6_0_0_alpha2;
+    }
+    public void testResolveReleasedVersionsForUnstableBranch() {
+        Tuple<List<Version>, List<Version>> t = VersionUtils.resolveReleasedVersions(TestUnstableBranch.CURRENT,
+                TestUnstableBranch.class);
+        List<Version> released = t.v1();
+        List<Version> unreleased = t.v2();
+        assertEquals(Arrays.asList(TestUnstableBranch.V_5_3_0, TestUnstableBranch.V_5_3_1,
+                TestUnstableBranch.V_6_0_0_alpha1, TestUnstableBranch.V_6_0_0_alpha2), released);
+        assertEquals(Arrays.asList(TestUnstableBranch.V_5_3_2, TestUnstableBranch.V_5_4_0), unreleased);
+    }
+
+    // TODO add a test that compares gradle and VersionUtils.java in a followup
+}
diff --git a/test/framework/src/test/java/org/elasticsearch/test/test/VersionUtilsTests.java b/test/framework/src/test/java/org/elasticsearch/test/test/VersionUtilsTests.java
deleted file mode 100644
index 5641917bc4..0000000000
--- a/test/framework/src/test/java/org/elasticsearch/test/test/VersionUtilsTests.java
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.elasticsearch.test.test;
-
-import org.elasticsearch.Version;
-import org.elasticsearch.test.ESTestCase;
-import org.elasticsearch.test.VersionUtils;
-
-import java.util.List;
-
-public class VersionUtilsTests extends ESTestCase {
-
-    public void testAllVersionsSorted() {
-        List<Version> allVersions = VersionUtils.allReleasedVersions();
-        for (int i = 0, j = 1; j < allVersions.size(); ++i, ++j) {
-            assertTrue(allVersions.get(i).before(allVersions.get(j)));
-        }
-    }
-
-    public void testRandomVersionBetween() {
-        // full range
-        Version got = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(), Version.CURRENT);
-        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
-        assertTrue(got.onOrBefore(Version.CURRENT));
-        got = VersionUtils.randomVersionBetween(random(), null, Version.CURRENT);
-        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
-        assertTrue(got.onOrBefore(Version.CURRENT));
-        got = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(), null);
-        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
-        assertTrue(got.onOrBefore(Version.CURRENT));
-
-        // sub range
-        got = VersionUtils.randomVersionBetween(random(), Version.V_5_0_0,
-                Version.V_6_0_0_alpha2_UNRELEASED);
-        assertTrue(got.onOrAfter(Version.V_5_0_0));
-        assertTrue(got.onOrBefore(Version.V_6_0_0_alpha2_UNRELEASED));
-
-        // unbounded lower
-        got = VersionUtils.randomVersionBetween(random(), null, Version.V_6_0_0_alpha2_UNRELEASED);
-        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
-        assertTrue(got.onOrBefore(Version.V_6_0_0_alpha2_UNRELEASED));
-        got = VersionUtils.randomVersionBetween(random(), null, VersionUtils.allReleasedVersions().get(0));
-        assertTrue(got.onOrAfter(VersionUtils.getFirstVersion()));
-        assertTrue(got.onOrBefore(VersionUtils.allReleasedVersions().get(0)));
-
-        // unbounded upper
-        got = VersionUtils.randomVersionBetween(random(), Version.V_5_0_0, null);
-        assertTrue(got.onOrAfter(Version.V_5_0_0));
-        assertTrue(got.onOrBefore(Version.CURRENT));
-        got = VersionUtils.randomVersionBetween(random(), VersionUtils.getPreviousVersion(), null);
-        assertTrue(got.onOrAfter(VersionUtils.getPreviousVersion()));
-        assertTrue(got.onOrBefore(Version.CURRENT));
-
-        // range of one
-        got = VersionUtils.randomVersionBetween(random(), VersionUtils.getFirstVersion(), VersionUtils.getFirstVersion());
-        assertEquals(got, VersionUtils.getFirstVersion());
-        got = VersionUtils.randomVersionBetween(random(), Version.CURRENT, Version.CURRENT);
-        assertEquals(got, Version.CURRENT);
-        got = VersionUtils.randomVersionBetween(random(), Version.V_6_0_0_alpha2_UNRELEASED,
-                Version.V_6_0_0_alpha2_UNRELEASED);
-        assertEquals(got, Version.V_6_0_0_alpha2_UNRELEASED);
-
-        // implicit range of one
-        got = VersionUtils.randomVersionBetween(random(), null, VersionUtils.getFirstVersion());
-        assertEquals(got, VersionUtils.getFirstVersion());
-        got = VersionUtils.randomVersionBetween(random(), Version.CURRENT, null);
-        assertEquals(got, Version.CURRENT);
-    }
-}