add index versioning

server/src/main/java/org/elasticsearch/index/IndexSortConfig.java

@@ -106,18 +106,19 @@ public final class IndexSortConfig {
  static {
  FieldSortSpec timeStampSpec = new FieldSortSpec(DataStreamTimestampFieldMapper.DEFAULT_PATH);
  timeStampSpec.order = SortOrder.DESC;
+ TIME_SERIES_SORT = new FieldSortSpec[] { new FieldSortSpec(TimeSeriesIdFieldMapper.NAME), timeStampSpec };
  TIMESTAMP_SORT = new FieldSortSpec[] { timeStampSpec };
 
- // No descending ordering for host name and timestamp.
  FieldSortSpec hostnameSpec = new FieldSortSpec(IndexMode.HOST_NAME);
- HOSTNAME_TIMESTAMP_BWC_SORT = new FieldSortSpec[] { hostnameSpec, new FieldSortSpec(DataStreamTimestampFieldMapper.DEFAULT_PATH) };
-
  hostnameSpec.order = SortOrder.DESC;
- hostnameSpec.missingValue = "_first";
+ hostnameSpec.missingValue = "_last";
  hostnameSpec.mode = MultiValueMode.MIN;
  HOSTNAME_TIMESTAMP_SORT = new FieldSortSpec[] { hostnameSpec, timeStampSpec };
 
- TIME_SERIES_SORT = new FieldSortSpec[] { new FieldSortSpec(TimeSeriesIdFieldMapper.NAME), timeStampSpec };
+ // Older indexes use ascending ordering for host name and timestamp.
+ HOSTNAME_TIMESTAMP_BWC_SORT = new FieldSortSpec[] {
+ new FieldSortSpec(IndexMode.HOST_NAME),
+ new FieldSortSpec(DataStreamTimestampFieldMapper.DEFAULT_PATH) };
  }
 
  private static String validateMissingValue(String missing) {