// Backup should NOT be deleted when recreate fails (kept for recovery)
        boolean backupDeleted = false;
        for (final String deleted : testClient.deletedIndices) {
            if (deleted.contains(".backup.")) {
                backupDeleted = true;
                break;
            }
        }
        assertFalse(backupDeleted, "Backup should be kept for recovery when recreate fails");
    }

    @Test

    private static final String[] CAT_NAMES =
            { "aliases", "allocation", "count", "fielddata", "health", "indices", "master", "nodeattrs", "nodes", "pending_tasks",
                    "plugins", "recovery", "repositories", "thread_pool", "shards", "segments", "snapshots", "templates" };

    // ===================================================================================

                logger.warn("[Rebuild] Failed to rebuild index: {}", indexName, e);
                if (existsIndex(backupIndex)) {
                    logger.info("[Rebuild] Backup index {} remains for recovery", backupIndex);
                }
                success = false;
            }
        }
        return success;
    }

    /**
     * Atomically switches aliases from one index to another.