@Override
  public TShowTTLResp showTTL(TShowTTLReq req) {
    ShowTTLResp showTTLResp =
        (ShowTTLResp)
            configManager.showTTL(new ShowTTLPlan(req.getPathPattern().toArray(new String[0])));
    return showTTLResp.convertToRPCTShowTTLResp();
  }
ConfigNodeRPCServer exposes the interface that interacts with the DataNode
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/service/thrift/ConfigNodeRPCServiceProcessor.java