@Override
  public TSStatus setTTL(final TSetTTLReq req) throws TException {
    return configManager.setTTL(new SetTTLPlan(req.getPathPattern(), req.getTTL()));
  }
ConfigNodeRPCServer exposes the interface that interacts with the DataNode
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/service/thrift/ConfigNodeRPCServiceProcessor.java