Make default version dep.

Author: jasontedor

server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java

@@ -366,8 +366,15 @@ public ClusterState execute(ClusterState currentState) throws Exception {
                 }
                 // now, put the request settings, so they override templates
                 indexSettingsBuilder.put(request.settings());
+                if (indexSettingsBuilder.get(SETTING_VERSION_CREATED) == null) {
+                    DiscoveryNodes nodes = currentState.nodes();
+                    final Version createdVersion = Version.min(Version.CURRENT, nodes.getSmallestNonClientNodeVersion());
+                    indexSettingsBuilder.put(SETTING_VERSION_CREATED, createdVersion);
+                }
                 if (indexSettingsBuilder.get(SETTING_NUMBER_OF_SHARDS) == null) {
-                    indexSettingsBuilder.put(SETTING_NUMBER_OF_SHARDS, settings.getAsInt(SETTING_NUMBER_OF_SHARDS, 1));
+                    final int numberOfShards = getNumberOfShards(indexSettingsBuilder);
+
+                    indexSettingsBuilder.put(SETTING_NUMBER_OF_SHARDS, settings.getAsInt(SETTING_NUMBER_OF_SHARDS, numberOfShards));
                 }
                 if (indexSettingsBuilder.get(SETTING_NUMBER_OF_REPLICAS) == null) {
                     indexSettingsBuilder.put(SETTING_NUMBER_OF_REPLICAS, settings.getAsInt(SETTING_NUMBER_OF_REPLICAS, 1));
@@ -376,12 +383,6 @@ public ClusterState execute(ClusterState currentState) throws Exception {
                     indexSettingsBuilder.put(SETTING_AUTO_EXPAND_REPLICAS, settings.get(SETTING_AUTO_EXPAND_REPLICAS));
                 }
 
-                if (indexSettingsBuilder.get(SETTING_VERSION_CREATED) == null) {
-                    DiscoveryNodes nodes = currentState.nodes();
-                    final Version createdVersion = Version.min(Version.CURRENT, nodes.getSmallestNonClientNodeVersion());
-                    indexSettingsBuilder.put(SETTING_VERSION_CREATED, createdVersion);
-                }
-
                 if (indexSettingsBuilder.get(SETTING_CREATION_DATE) == null) {
                     indexSettingsBuilder.put(SETTING_CREATION_DATE, new DateTime(DateTimeZone.UTC).getMillis());
                 }
@@ -573,6 +574,18 @@ public ClusterState execute(ClusterState currentState) throws Exception {
             }
         }
 
+        static int getNumberOfShards(Settings.Builder indexSettingsBuilder) {
+            // TODO: this logic can be removed when the current major version is 8
+            assert Version.CURRENT.major == 7;
+            final int numberOfShards;
+            if (Version.fromId(Integer.parseInt(indexSettingsBuilder.get(SETTING_VERSION_CREATED))).before(Version.V_7_0_0_alpha1)) {
+                numberOfShards = 5;
+            } else {
+                numberOfShards = 1;
+            }
+            return numberOfShards;
+        }
+
         @Override
         public void onFailure(String source, Exception e) {
             if (e instanceof ResourceAlreadyExistsException) {

server/src/test/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexServiceTests.java

@@ -56,6 +56,7 @@
 import java.util.stream.Stream;
 
 import static java.util.Collections.emptyMap;
+import static org.elasticsearch.cluster.metadata.IndexMetaData.SETTING_VERSION_CREATED;
 import static org.hamcrest.Matchers.endsWith;
 import static org.hamcrest.Matchers.equalTo;
 
@@ -92,6 +93,21 @@ public static boolean isSplitable(int source, int target) {
         return source * x == target;
     }
 
+    public void testNumberOfShards() {
+        {
+            final Version versionCreated =
+                    VersionUtils.randomVersionBetween(random(), Version.V_6_0_0_alpha1, VersionUtils.getPreviousVersion(Version.V_7_0_0_alpha1));
+            final Settings.Builder indexSettingsBuilder = Settings.builder().put(SETTING_VERSION_CREATED, versionCreated);
+            assertThat(MetaDataCreateIndexService.IndexCreationTask.getNumberOfShards(indexSettingsBuilder), equalTo(5));
+        }
+        {
+            final Version versionCreated =
+                    VersionUtils.randomVersionBetween(random(), Version.V_7_0_0_alpha1, Version.CURRENT);
+            final Settings.Builder indexSettingsBuilder = Settings.builder().put(SETTING_VERSION_CREATED, versionCreated);
+            assertThat(MetaDataCreateIndexService.IndexCreationTask.getNumberOfShards(indexSettingsBuilder), equalTo(1));
+        }
+    }
+
     public void testValidateShrinkIndex() {
         int numShards = randomIntBetween(2, 42);
         ClusterState state = createClusterState("source", numShards, randomIntBetween(0, 10),