Fixing DataLifecycleServiceIT.testAutomaticForceMerge (#96226)

modules/dlm/src/internalClusterTest/java/org/elasticsearch/dlm/DataLifecycleServiceIT.java

@@ -260,7 +260,6 @@ public class DataLifecycleServiceIT extends ESIntegTestCase {
         });
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/96084")
     public void testAutomaticForceMerge() throws Exception {
         /*
          * This test makes sure that (1) DLM does _not_ call forcemerge on an index in the same DLM pass when it rolls over the index and
@@ -295,26 +294,29 @@ public class DataLifecycleServiceIT extends ESIntegTestCase {
                 FlushResponse flushResponse = client().admin().indices().flush(new FlushRequest(toBeRolledOverIndex)).actionGet();
                 assertThat(flushResponse.getStatus(), equalTo(RestStatus.OK));
             }
-            /*
-             * Without the following, calls to forcemerge are essentially a no-op since it has already done automatic merging. Setting
-             * merge_factor on its own does not do anything, but it results in calls to forcemerge making observable changes to the
-             * number of segments. So we're doing this just so that we can check that DLM did actually call forcemerge.
-             */
-            updateIndexSettings(
-                Settings.builder().put(MergePolicyConfig.INDEX_MERGE_POLICY_MERGE_FACTOR_SETTING.getKey(), 5),
-                toBeRolledOverIndex
-            );
 
             final String toBeForceMergedIndex;
             final int preDlmSegmentsForceMergedIndex;
+
             if (currentGeneration == 1) {
                 toBeForceMergedIndex = null; // Not going to be used
                 preDlmSegmentsForceMergedIndex = -1; // Not going to be used
             } else {
                 toBeForceMergedIndex = DataStream.getDefaultBackingIndexName(dataStreamName, currentGeneration - 1);
                 preDlmSegmentsForceMergedIndex = getSegmentCount(toBeForceMergedIndex);
+                logger.info("preDlmSegmentsForceMergedIndex: {}", preDlmSegmentsForceMergedIndex);
             }
             final int preDlmSegmentsAboutToBeRolledOverIndex = getSegmentCount(toBeRolledOverIndex);
+            logger.info("preDlmSegmentsAboutToBeRolledOverIndex: {}", preDlmSegmentsAboutToBeRolledOverIndex);
+            /*
+             * Without the following, calls to forcemerge are essentially a no-op since it has already done automatic merging. Setting
+             * merge_factor on its own does not do anything, but it results in calls to forcemerge making observable changes to the
+             * number of segments. So we're doing this just so that we can check that DLM did actually call forcemerge.
+             */
+            updateIndexSettings(
+                Settings.builder().put(MergePolicyConfig.INDEX_MERGE_POLICY_MERGE_FACTOR_SETTING.getKey(), 5),
+                toBeRolledOverIndex
+            );
             int currentBackingIndexCount = currentGeneration;
             DataLifecycleService dataLifecycleService = internalCluster().getInstance(
                 DataLifecycleService.class,
@@ -346,6 +348,7 @@ public class DataLifecycleServiceIT extends ESIntegTestCase {
                         postDlmSegmentsForceMergedIndex,
                         lessThan(preDlmSegmentsForceMergedIndex)
                     );
+                    logger.info("postDlmSegmentsForceMergedIndex: {}", postDlmSegmentsForceMergedIndex);
                 }
                 // We want to assert that when DLM rolls over the write index it, it doesn't forcemerge it on that iteration:
                 assertThat(
@@ -357,10 +360,6 @@ public class DataLifecycleServiceIT extends ESIntegTestCase {
         }
     }
 
-    private static void enableDLM(TimeValue pollInterval) {
-        updateClusterSettings(Settings.builder().put(DataLifecycleService.DLM_POLL_INTERVAL, pollInterval));
-    }
-
     private static void disableDLM() {
         updateClusterSettings(Settings.builder().put(DataLifecycleService.DLM_POLL_INTERVAL, TimeValue.MAX_VALUE));
     }