private HashSet<PersistentID> finishDiskStoreBackups(
      Map<DiskStoreImpl, DiskStoreBackup> backupByDiskStores) throws IOException {
    HashSet<PersistentID> persistentIds = new HashSet<>();
    for (Map.Entry<DiskStoreImpl, DiskStoreBackup> entry : backupByDiskStores.entrySet()) {
      DiskStoreImpl diskStore = entry.getKey();
      completeBackup(diskStore, entry.getValue());
      diskStore.getStats().endBackup();
      persistentIds.add(diskStore.getPersistentID());
    }
    return persistentIds;
  }
This class manages the state an logic to backup a single cache.
geode-core/src/main/java/org/apache/geode/internal/cache/backup/BackupTask.java