Remove ensureIndexHasHistoryUUID (#47043)

We no longer use this method in production code.

Author: dnhatn

server/src/main/java/org/elasticsearch/index/store/Store.java

@@ -1484,22 +1484,6 @@ public void associateIndexWithNewTranslog(final String translogUUID) throws IOEx
         }
     }
 
-
-    /**
-     * Checks that the Lucene index contains a history uuid marker. If not, a new one is generated and committed.
-     */
-    public void ensureIndexHasHistoryUUID() throws IOException {
-        metadataLock.writeLock().lock();
-        try (IndexWriter writer = newAppendingIndexWriter(directory, null)) {
-            final Map<String, String> userData = getUserData(writer);
-            if (userData.containsKey(Engine.HISTORY_UUID_KEY) == false) {
-                updateCommitData(writer, Collections.singletonMap(Engine.HISTORY_UUID_KEY, UUIDs.randomBase64UUID()));
-            }
-        } finally {
-            metadataLock.writeLock().unlock();
-        }
-    }
-
     /**
      * Keeping existing unsafe commits when opening an engine can be problematic because these commits are not safe
      * at the recovering time but they can suddenly become safe in the future.

server/src/test/java/org/elasticsearch/index/store/StoreTests.java

@@ -1029,38 +1029,6 @@ public void testCanReadOldCorruptionMarker() throws IOException {
         store.close();
     }
 
-    public void testEnsureIndexHasHistoryUUID() throws IOException {
-        final ShardId shardId = new ShardId("index", "_na_", 1);
-        try (Store store = new Store(shardId, INDEX_SETTINGS, StoreTests.newDirectory(random()), new DummyShardLock(shardId))) {
-
-            store.createEmpty(Version.LATEST);
-
-            // remove the history uuid
-            IndexWriterConfig iwc = new IndexWriterConfig(null)
-                .setCommitOnClose(false)
-                // we don't want merges to happen here - we call maybe merge on the engine
-                // later once we stared it up otherwise we would need to wait for it here
-                // we also don't specify a codec here and merges should use the engines for this index
-                .setMergePolicy(NoMergePolicy.INSTANCE)
-                .setOpenMode(IndexWriterConfig.OpenMode.APPEND);
-            try (IndexWriter writer = new IndexWriter(store.directory(), iwc)) {
-                Map<String, String> newCommitData = new HashMap<>();
-                for (Map.Entry<String, String> entry : writer.getLiveCommitData()) {
-                    if (entry.getKey().equals(Engine.HISTORY_UUID_KEY) == false) {
-                        newCommitData.put(entry.getKey(), entry.getValue());
-                    }
-                }
-                writer.setLiveCommitData(newCommitData.entrySet());
-                writer.commit();
-            }
-
-            store.ensureIndexHasHistoryUUID();
-
-            SegmentInfos segmentInfos = Lucene.readSegmentInfos(store.directory());
-            assertThat(segmentInfos.getUserData(), hasKey(Engine.HISTORY_UUID_KEY));
-        }
-    }
-
     public void testHistoryUUIDCanBeForced() throws IOException {
         final ShardId shardId = new ShardId("index", "_na_", 1);
         try (Store store = new Store(shardId, INDEX_SETTINGS, StoreTests.newDirectory(random()), new DummyShardLock(shardId))) {