Merge branch 'main' into esql-MV_CONTAINS_ALL

Author: mjmbischoff

x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/DataStreamsUpgradeIT.java

@@ -208,19 +208,21 @@ public void testUpgradeDataStream() throws Exception {
             createDataStreamFromNonDataStreamIndices(dataStreamFromNonDataStreamIndices);
         } else if (CLUSTER_TYPE == ClusterType.UPGRADED) {
             Map<String, Map<String, Object>> oldIndicesMetadata = getIndicesMetadata(dataStreamName);
+            String oldWriteIndex = getDataStreamBackingIndexNames(dataStreamName).getLast();
             upgradeDataStream(dataStreamName, numRollovers, numRollovers + 1, 0, ilmEnabled);
             cancelReindexTask(dataStreamName);
             upgradeDataStream(dataStreamFromNonDataStreamIndices, 0, 1, 0, ilmEnabled);
             cancelReindexTask(dataStreamFromNonDataStreamIndices);
             Map<String, Map<String, Object>> upgradedIndicesMetadata = getIndicesMetadata(dataStreamName);
+            String newWriteIndex = getDataStreamBackingIndexNames(dataStreamName).getLast();
 
             if (ilmEnabled) {
-                checkILMPhase(dataStreamName, upgradedIndicesMetadata);
+                checkILMPhase(dataStreamName, newWriteIndex);
                 // Delete the data streams to avoid ILM continuously running cluster state tasks, see
                 // https://github.com/elastic/elasticsearch/issues/129097#issuecomment-3016122739
                 deleteDataStream(dataStreamName);
             } else {
-                compareIndexMetadata(oldIndicesMetadata, upgradedIndicesMetadata);
+                compareIndexMetadata(oldIndicesMetadata, oldWriteIndex, upgradedIndicesMetadata);
             }
         }
     }
@@ -262,9 +264,9 @@ private void cancelReindexTask(String dataStreamName) throws IOException {
 
     private void compareIndexMetadata(
         Map<String, Map<String, Object>> oldIndicesMetadata,
+        String oldWriteIndex,
         Map<String, Map<String, Object>> upgradedIndicesMetadata
     ) {
-        String oldWriteIndex = getWriteIndexFromDataStreamIndexMetadata(oldIndicesMetadata);
         for (Map.Entry<String, Map<String, Object>> upgradedIndexEntry : upgradedIndicesMetadata.entrySet()) {
             String upgradedIndexName = upgradedIndexEntry.getKey();
             if (upgradedIndexName.startsWith(".migrated-")) {
@@ -287,10 +289,8 @@ private void compareIndexMetadata(
     }
 
     @SuppressWarnings("unchecked")
-    private void checkILMPhase(String dataStreamName, Map<String, Map<String, Object>> upgradedIndicesMetadata) throws Exception {
-        var writeIndex = getWriteIndexFromDataStreamIndexMetadata(upgradedIndicesMetadata);
+    private void checkILMPhase(String dataStreamName, String writeIndex) throws Exception {
         assertBusy(() -> {
-
             Request request = new Request("GET", dataStreamName + "/_ilm/explain");
             Response response = client().performRequest(request);
             Map<String, Object> responseMap = XContentHelper.convertToMap(
@@ -302,21 +302,12 @@ private void checkILMPhase(String dataStreamName, Map<String, Map<String, Object
             for (var index : indices.keySet()) {
                 if (index.equals(writeIndex) == false) {
                     Map<String, Object> ilmInfo = (Map<String, Object>) indices.get(index);
-                    assertThat("Index has not moved to cold ILM phase", ilmInfo.get("phase"), equalTo("cold"));
+                    assertThat("Index [" + index + "] has not moved to cold ILM phase, " + indices, ilmInfo.get("phase"), equalTo("cold"));
                 }
             }
         }, 30, TimeUnit.SECONDS);
     }
 
-    private String getWriteIndexFromDataStreamIndexMetadata(Map<String, Map<String, Object>> indexMetadataForDataStream) {
-        return indexMetadataForDataStream.entrySet()
-            .stream()
-            .sorted((o1, o2) -> Long.compare(getCreationDate(o2.getValue()), getCreationDate(o1.getValue())))
-            .map(Map.Entry::getKey)
-            .findFirst()
-            .get();
-    }
-
     private void startILM() throws IOException {
         setILMInterval();
         var request = new Request("POST", "/_ilm/start");