graph_brpc_server.cc

// Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "paddle/fluid/distributed/service/graph_brpc_server.h"
#include "paddle/fluid/distributed/service/brpc_ps_server.h"

#include <thread>  // NOLINT
#include <utility>
#include "butil/endpoint.h"
#include "iomanip"
#include "paddle/fluid/distributed/service/brpc_ps_client.h"
#include "paddle/fluid/framework/archive.h"
#include "paddle/fluid/platform/profiler.h"
namespace paddle {
namespace distributed {

#define CHECK_TABLE_EXIST(table, request, response)        \
  if (table == NULL) {                                     \
    std::string err_msg("table not found with table_id:"); \
    err_msg.append(std::to_string(request.table_id()));    \
    set_response_code(response, -1, err_msg.c_str());      \
    return -1;                                             \
  }

int32_t GraphBrpcServer::initialize() {
  auto &service_config = _config.downpour_server_param().service_param();
  if (!service_config.has_service_class()) {
    LOG(ERROR) << "miss service_class in ServerServiceParameter";
    return -1;
  }
  auto *service =
      CREATE_PSCORE_CLASS(PsBaseService, service_config.service_class());
  if (service == NULL) {
    LOG(ERROR) << "service is unregistered, service_name:"
               << service_config.service_class();
    return -1;
  }

  _service.reset(service);
  if (service->configure(this) != 0 || service->initialize() != 0) {
    LOG(ERROR) << "service initialize failed, service_name:"
               << service_config.service_class();
    return -1;
  }
  if (_server.AddService(service, brpc::SERVER_DOESNT_OWN_SERVICE) != 0) {
    LOG(ERROR) << "service add to brpc failed, service:"
               << service_config.service_class();
    return -1;
  }
  return 0;
}

brpc::Channel *GraphBrpcServer::get_cmd_channel(size_t server_index) {
  return _pserver_channels[server_index].get();
}

uint64_t GraphBrpcServer::start(const std::string &ip, uint32_t port) {
  std::unique_lock<std::mutex> lock(mutex_);

  std::string ip_port = ip + ":" + std::to_string(port);
  VLOG(3) << "server of rank " << _rank << " starts at " << ip_port;
  brpc::ServerOptions options;

  int num_threads = std::thread::hardware_concurrency();
  auto trainers = _environment->get_trainers();
  options.num_threads = trainers > num_threads ? trainers : num_threads;

  if (_server.Start(ip_port.c_str(), &options) != 0) {
    LOG(ERROR) << "GraphBrpcServer start failed, ip_port=" << ip_port;
    return 0;
  }
  _environment->registe_ps_server(ip, port, _rank);
  return 0;
}

int32_t GraphBrpcServer::build_peer2peer_connection(int rank) {
  this->rank = rank;
  auto _env = environment();
  brpc::ChannelOptions options;
  options.protocol = "baidu_std";
  options.timeout_ms = 500000;
  options.connection_type = "pooled";
  options.connect_timeout_ms = 10000;
  options.max_retry = 3;

  std::vector<PSHost> server_list = _env->get_ps_servers();
  _pserver_channels.resize(server_list.size());
  std::ostringstream os;
  std::string server_ip_port;
  for (size_t i = 0; i < server_list.size(); ++i) {
    server_ip_port.assign(server_list[i].ip.c_str());
    server_ip_port.append(":");
    server_ip_port.append(std::to_string(server_list[i].port));
    _pserver_channels[i].reset(new brpc::Channel());
    if (_pserver_channels[i]->Init(server_ip_port.c_str(), "", &options) != 0) {
      VLOG(0) << "GraphServer connect to Server:" << server_ip_port
              << " Failed! Try again.";
      std::string int_ip_port =
          GetIntTypeEndpoint(server_list[i].ip, server_list[i].port);
      if (_pserver_channels[i]->Init(int_ip_port.c_str(), "", &options) != 0) {
        LOG(ERROR) << "GraphServer connect to Server:" << int_ip_port
                   << " Failed!";
        return -1;
      }
    }
    os << server_ip_port << ",";
  }
  LOG(INFO) << "servers peer2peer connection success:" << os.str();
  return 0;
}

int32_t GraphBrpcService::clear_nodes(Table *table,
                                      const PsRequestMessage &request,
                                      PsResponseMessage &response,
                                      brpc::Controller *cntl) {
  ((GraphTable *)table)->clear_nodes();
  return 0;
}

int32_t GraphBrpcService::add_graph_node(Table *table,
                                         const PsRequestMessage &request,
                                         PsResponseMessage &response,
                                         brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 1) {
    set_response_code(
        response, -1,
        "graph_get_node_feat request requires at least 2 arguments");
    return 0;
  }

  size_t node_num = request.params(0).size() / sizeof(uint64_t);
  uint64_t *node_data = (uint64_t *)(request.params(0).c_str());
  std::vector<uint64_t> node_ids(node_data, node_data + node_num);
  std::vector<bool> is_weighted_list;
  if (request.params_size() == 2) {
    size_t weight_list_size = request.params(1).size() / sizeof(bool);
    bool *is_weighted_buffer = (bool *)(request.params(1).c_str());
    is_weighted_list = std::vector<bool>(is_weighted_buffer,
                                         is_weighted_buffer + weight_list_size);
  }

  ((GraphTable *)table)->add_graph_node(node_ids, is_weighted_list);
  return 0;
}
int32_t GraphBrpcService::remove_graph_node(Table *table,
                                            const PsRequestMessage &request,
                                            PsResponseMessage &response,
                                            brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 1) {
    set_response_code(
        response, -1,
        "graph_get_node_feat request requires at least 1 argument");
    return 0;
  }
  size_t node_num = request.params(0).size() / sizeof(uint64_t);
  uint64_t *node_data = (uint64_t *)(request.params(0).c_str());
  std::vector<uint64_t> node_ids(node_data, node_data + node_num);

  ((GraphTable *)table)->remove_graph_node(node_ids);
  return 0;
}
int32_t GraphBrpcServer::port() { return _server.listen_address().port; }

int32_t GraphBrpcService::initialize() {
  _is_initialize_shard_info = false;
  _service_handler_map[PS_STOP_SERVER] = &GraphBrpcService::stop_server;
  _service_handler_map[PS_LOAD_ONE_TABLE] = &GraphBrpcService::load_one_table;
  _service_handler_map[PS_LOAD_ALL_TABLE] = &GraphBrpcService::load_all_table;

  _service_handler_map[PS_PRINT_TABLE_STAT] =
      &GraphBrpcService::print_table_stat;
  _service_handler_map[PS_BARRIER] = &GraphBrpcService::barrier;
  _service_handler_map[PS_START_PROFILER] = &GraphBrpcService::start_profiler;
  _service_handler_map[PS_STOP_PROFILER] = &GraphBrpcService::stop_profiler;

  _service_handler_map[PS_PULL_GRAPH_LIST] = &GraphBrpcService::pull_graph_list;
  _service_handler_map[PS_GRAPH_SAMPLE_NEIGHBORS] =
      &GraphBrpcService::graph_random_sample_neighbors;
  _service_handler_map[PS_GRAPH_SAMPLE_NODES] =
      &GraphBrpcService::graph_random_sample_nodes;
  _service_handler_map[PS_GRAPH_GET_NODE_FEAT] =
      &GraphBrpcService::graph_get_node_feat;
  _service_handler_map[PS_GRAPH_CLEAR] = &GraphBrpcService::clear_nodes;
  _service_handler_map[PS_GRAPH_ADD_GRAPH_NODE] =
      &GraphBrpcService::add_graph_node;
  _service_handler_map[PS_GRAPH_REMOVE_GRAPH_NODE] =
      &GraphBrpcService::remove_graph_node;
  _service_handler_map[PS_GRAPH_SET_NODE_FEAT] =
      &GraphBrpcService::graph_set_node_feat;
  _service_handler_map[PS_GRAPH_SAMPLE_NODES_FROM_ONE_SERVER] =
      &GraphBrpcService::sample_neighbors_across_multi_servers;
  _service_handler_map[PS_GRAPH_USE_NEIGHBORS_SAMPLE_CACHE] =
      &GraphBrpcService::use_neighbors_sample_cache;
  // shard初始化,server启动后才可从env获取到server_list的shard信息
  initialize_shard_info();

  return 0;
}

int32_t GraphBrpcService::initialize_shard_info() {
  if (!_is_initialize_shard_info) {
    std::lock_guard<std::mutex> guard(_initialize_shard_mutex);
    if (_is_initialize_shard_info) {
      return 0;
    }
    server_size = _server->environment()->get_ps_servers().size();
    auto &table_map = *(_server->table());
    for (auto itr : table_map) {
      itr.second->set_shard(_rank, server_size);
    }
    _is_initialize_shard_info = true;
  }
  return 0;
}

void GraphBrpcService::service(google::protobuf::RpcController *cntl_base,
                               const PsRequestMessage *request,
                               PsResponseMessage *response,
                               google::protobuf::Closure *done) {
  brpc::ClosureGuard done_guard(done);
  std::string log_label("ReceiveCmd-");
  if (!request->has_table_id()) {
    set_response_code(*response, -1, "PsRequestMessage.tabel_id is required");
    return;
  }

  response->set_err_code(0);
  response->set_err_msg("");
  auto *table = _server->table(request->table_id());
  brpc::Controller *cntl = static_cast<brpc::Controller *>(cntl_base);
  auto itr = _service_handler_map.find(request->cmd_id());
  if (itr == _service_handler_map.end()) {
    std::string err_msg(
        "undefined cmd_id, should match PsCmdID in ps.proto, cmd_id:");
    err_msg.append(std::to_string(request->cmd_id()));
    set_response_code(*response, -1, err_msg.c_str());
    return;
  }
  serviceFunc handler_func = itr->second;
  int service_ret = (this->*handler_func)(table, *request, *response, cntl);
  if (service_ret != 0) {
    response->set_err_code(service_ret);
    if (!response->has_err_msg()) {
      response->set_err_msg("server internal error");
    }
  }
}

int32_t GraphBrpcService::barrier(Table *table, const PsRequestMessage &request,
                                  PsResponseMessage &response,
                                  brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)

  if (request.params_size() < 1) {
    set_response_code(response, -1,
                      "PsRequestMessage.params is requeired at "
                      "least 1 for num of sparse_key");
    return 0;
  }

  auto trainer_id = request.client_id();
  auto barrier_type = request.params(0);
  table->barrier(trainer_id, barrier_type);
  return 0;
}

int32_t GraphBrpcService::print_table_stat(Table *table,
                                           const PsRequestMessage &request,
                                           PsResponseMessage &response,
                                           brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  std::pair<int64_t, int64_t> ret = table->print_table_stat();
  paddle::framework::BinaryArchive ar;
  ar << ret.first << ret.second;
  std::string table_info(ar.Buffer(), ar.Length());
  response.set_data(table_info);

  return 0;
}

int32_t GraphBrpcService::load_one_table(Table *table,
                                         const PsRequestMessage &request,
                                         PsResponseMessage &response,
                                         brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 2) {
    set_response_code(
        response, -1,
        "PsRequestMessage.datas is requeired at least 2 for path & load_param");
    return -1;
  }
  if (table->load(request.params(0), request.params(1)) != 0) {
    set_response_code(response, -1, "table load failed");
    return -1;
  }
  return 0;
}

int32_t GraphBrpcService::load_all_table(Table *table,
                                         const PsRequestMessage &request,
                                         PsResponseMessage &response,
                                         brpc::Controller *cntl) {
  auto &table_map = *(_server->table());
  for (auto &itr : table_map) {
    if (load_one_table(itr.second.get(), request, response, cntl) != 0) {
      LOG(ERROR) << "load table[" << itr.first << "] failed";
      return -1;
    }
  }
  return 0;
}

int32_t GraphBrpcService::stop_server(Table *table,
                                      const PsRequestMessage &request,
                                      PsResponseMessage &response,
                                      brpc::Controller *cntl) {
  GraphBrpcServer *p_server = (GraphBrpcServer *)_server;
  std::thread t_stop([p_server]() {
    p_server->stop();
    LOG(INFO) << "Server Stoped";
  });
  p_server->export_cv()->notify_all();
  t_stop.detach();
  return 0;
}

int32_t GraphBrpcService::stop_profiler(Table *table,
                                        const PsRequestMessage &request,
                                        PsResponseMessage &response,
                                        brpc::Controller *cntl) {
  platform::DisableProfiler(platform::EventSortingKey::kDefault,
                            string::Sprintf("server_%s_profile", _rank));
  return 0;
}

int32_t GraphBrpcService::start_profiler(Table *table,
                                         const PsRequestMessage &request,
                                         PsResponseMessage &response,
                                         brpc::Controller *cntl) {
  platform::EnableProfiler(platform::ProfilerState::kCPU);
  return 0;
}

int32_t GraphBrpcService::pull_graph_list(Table *table,
                                          const PsRequestMessage &request,
                                          PsResponseMessage &response,
                                          brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 3) {
    set_response_code(response, -1,
                      "pull_graph_list request requires at least 3 arguments");
    return 0;
  }
  int start = *(int *)(request.params(0).c_str());
  int size = *(int *)(request.params(1).c_str());
  int step = *(int *)(request.params(2).c_str());
  std::unique_ptr<char[]> buffer;
  int actual_size;
  ((GraphTable *)table)
      ->pull_graph_list(start, size, buffer, actual_size, false, step);
  cntl->response_attachment().append(buffer.get(), actual_size);
  return 0;
}
int32_t GraphBrpcService::graph_random_sample_neighbors(
    Table *table, const PsRequestMessage &request, PsResponseMessage &response,
    brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 2) {
    set_response_code(
        response, -1,
        "graph_random_sample request requires at least 2 arguments");
    return 0;
  }
  size_t node_num = request.params(0).size() / sizeof(uint64_t);
  uint64_t *node_data = (uint64_t *)(request.params(0).c_str());
  int sample_size = *(uint64_t *)(request.params(1).c_str());
  std::vector<std::shared_ptr<char>> buffers(node_num);
  std::vector<int> actual_sizes(node_num, 0);
  ((GraphTable *)table)
      ->random_sample_neighbors(node_data, sample_size, buffers, actual_sizes);

  cntl->response_attachment().append(&node_num, sizeof(size_t));
  cntl->response_attachment().append(actual_sizes.data(),
                                     sizeof(int) * node_num);
  for (size_t idx = 0; idx < node_num; ++idx) {
    cntl->response_attachment().append(buffers[idx].get(), actual_sizes[idx]);
  }
  return 0;
}
int32_t GraphBrpcService::graph_random_sample_nodes(
    Table *table, const PsRequestMessage &request, PsResponseMessage &response,
    brpc::Controller *cntl) {
  size_t size = *(uint64_t *)(request.params(0).c_str());
  std::unique_ptr<char[]> buffer;
  int actual_size;
  if (((GraphTable *)table)->random_sample_nodes(size, buffer, actual_size) ==
      0) {
    cntl->response_attachment().append(buffer.get(), actual_size);
  } else
    cntl->response_attachment().append(NULL, 0);

  return 0;
}

int32_t GraphBrpcService::graph_get_node_feat(Table *table,
                                              const PsRequestMessage &request,
                                              PsResponseMessage &response,
                                              brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 2) {
    set_response_code(
        response, -1,
        "graph_get_node_feat request requires at least 2 arguments");
    return 0;
  }
  size_t node_num = request.params(0).size() / sizeof(uint64_t);
  uint64_t *node_data = (uint64_t *)(request.params(0).c_str());
  std::vector<uint64_t> node_ids(node_data, node_data + node_num);

  std::vector<std::string> feature_names =
      paddle::string::split_string<std::string>(request.params(1), "\t");

  std::vector<std::vector<std::string>> feature(
      feature_names.size(), std::vector<std::string>(node_num));

  ((GraphTable *)table)->get_node_feat(node_ids, feature_names, feature);

  for (size_t feat_idx = 0; feat_idx < feature_names.size(); ++feat_idx) {
    for (size_t node_idx = 0; node_idx < node_num; ++node_idx) {
      size_t feat_len = feature[feat_idx][node_idx].size();
      cntl->response_attachment().append(&feat_len, sizeof(size_t));
      cntl->response_attachment().append(feature[feat_idx][node_idx].data(),
                                         feat_len);
    }
  }

  return 0;
}
int32_t GraphBrpcService::sample_neighbors_across_multi_servers(
    Table *table, const PsRequestMessage &request, PsResponseMessage &response,
    brpc::Controller *cntl) {
  // sleep(5);
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 2) {
    set_response_code(
        response, -1,
        "graph_random_neighbors_sample request requires at least 2 arguments");
    return 0;
  }
  size_t node_num = request.params(0).size() / sizeof(uint64_t),
         size_of_size_t = sizeof(size_t);
  uint64_t *node_data = (uint64_t *)(request.params(0).c_str());
  int sample_size = *(uint64_t *)(request.params(1).c_str());
  // std::vector<uint64_t> res = ((GraphTable
  // *)table).filter_out_non_exist_nodes(node_data, sample_size);
  std::vector<int> request2server;
  std::vector<int> server2request(server_size, -1);
  std::vector<uint64_t> local_id;
  std::vector<int> local_query_idx;
  size_t rank = get_rank();
  for (int query_idx = 0; query_idx < node_num; ++query_idx) {
    int server_index =
        ((GraphTable *)table)->get_server_index_by_id(node_data[query_idx]);
    if (server2request[server_index] == -1) {
      server2request[server_index] = request2server.size();
      request2server.push_back(server_index);
    }
  }
  if (server2request[rank] != -1) {
    auto pos = server2request[rank];
    std::swap(request2server[pos],
              request2server[(int)request2server.size() - 1]);
    server2request[request2server[pos]] = pos;
    server2request[request2server[(int)request2server.size() - 1]] =
        request2server.size() - 1;
  }
  size_t request_call_num = request2server.size();
  std::vector<std::shared_ptr<char>> local_buffers;
  std::vector<int> local_actual_sizes;
  std::vector<size_t> seq;
  std::vector<std::vector<uint64_t>> node_id_buckets(request_call_num);
  std::vector<std::vector<int>> query_idx_buckets(request_call_num);
  for (int query_idx = 0; query_idx < node_num; ++query_idx) {
    int server_index =
        ((GraphTable *)table)->get_server_index_by_id(node_data[query_idx]);
    int request_idx = server2request[server_index];
    node_id_buckets[request_idx].push_back(node_data[query_idx]);
    query_idx_buckets[request_idx].push_back(query_idx);
    seq.push_back(request_idx);
  }
  size_t remote_call_num = request_call_num;
  if (request2server.size() != 0 && request2server.back() == rank) {
    remote_call_num--;
    local_buffers.resize(node_id_buckets.back().size());
    local_actual_sizes.resize(node_id_buckets.back().size());
  }
  cntl->response_attachment().append(&node_num, sizeof(size_t));
  auto local_promise = std::make_shared<std::promise<int32_t>>();
  std::future<int> local_fut = local_promise->get_future();
  std::vector<bool> failed(server_size, false);
  std::function<void(void *)> func = [&, node_id_buckets, query_idx_buckets,
                                      request_call_num](void *done) {
    local_fut.get();
    std::vector<int> actual_size;
    auto *closure = (DownpourBrpcClosure *)done;
    std::vector<std::unique_ptr<butil::IOBufBytesIterator>> res(
        remote_call_num);
    size_t fail_num = 0;
    for (size_t request_idx = 0; request_idx < remote_call_num; ++request_idx) {
      if (closure->check_response(request_idx, PS_GRAPH_SAMPLE_NEIGHBORS) !=
          0) {
        ++fail_num;
        failed[request2server[request_idx]] = true;
      } else {
        auto &res_io_buffer = closure->cntl(request_idx)->response_attachment();
        size_t node_size;
        res[request_idx].reset(new butil::IOBufBytesIterator(res_io_buffer));
        size_t num;
        res[request_idx]->copy_and_forward(&num, sizeof(size_t));
      }
    }
    int size;
    int local_index = 0;
    for (size_t i = 0; i < node_num; i++) {
      if (fail_num > 0 && failed[seq[i]]) {
        size = 0;
      } else if (request2server[seq[i]] != rank) {
        res[seq[i]]->copy_and_forward(&size, sizeof(int));
      } else {
        size = local_actual_sizes[local_index++];
      }
      actual_size.push_back(size);
    }
    cntl->response_attachment().append(actual_size.data(),
                                       actual_size.size() * sizeof(int));

    local_index = 0;
    for (size_t i = 0; i < node_num; i++) {
      if (fail_num > 0 && failed[seq[i]]) {
        continue;
      } else if (request2server[seq[i]] != rank) {
        char temp[actual_size[i] + 1];
        res[seq[i]]->copy_and_forward(temp, actual_size[i]);
        cntl->response_attachment().append(temp, actual_size[i]);
      } else {
        char *temp = local_buffers[local_index++].get();
        cntl->response_attachment().append(temp, actual_size[i]);
      }
    }
    closure->set_promise_value(0);
  };

  DownpourBrpcClosure *closure = new DownpourBrpcClosure(remote_call_num, func);

  auto promise = std::make_shared<std::promise<int32_t>>();
  closure->add_promise(promise);
  std::future<int> fut = promise->get_future();

  for (int request_idx = 0; request_idx < remote_call_num; ++request_idx) {
    int server_index = request2server[request_idx];
    closure->request(request_idx)->set_cmd_id(PS_GRAPH_SAMPLE_NEIGHBORS);
    closure->request(request_idx)->set_table_id(request.table_id());
    closure->request(request_idx)->set_client_id(rank);
    size_t node_num = node_id_buckets[request_idx].size();

    closure->request(request_idx)
        ->add_params((char *)node_id_buckets[request_idx].data(),
                     sizeof(uint64_t) * node_num);
    closure->request(request_idx)
        ->add_params((char *)&sample_size, sizeof(int));
    PsService_Stub rpc_stub(
        ((GraphBrpcServer *)get_server())->get_cmd_channel(server_index));
    // GraphPsService_Stub rpc_stub =
    //     getServiceStub(get_cmd_channel(server_index));
    closure->cntl(request_idx)->set_log_id(butil::gettimeofday_ms());
    rpc_stub.service(closure->cntl(request_idx), closure->request(request_idx),
                     closure->response(request_idx), closure);
  }
  if (server2request[rank] != -1) {
    ((GraphTable *)table)
        ->random_sample_neighbors(node_id_buckets.back().data(), sample_size,
                                  local_buffers, local_actual_sizes);
  }
  local_promise.get()->set_value(0);
  if (remote_call_num == 0) func(closure);
  fut.get();
  return 0;
}
int32_t GraphBrpcService::graph_set_node_feat(Table *table,
                                              const PsRequestMessage &request,
                                              PsResponseMessage &response,
                                              brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 3) {
    set_response_code(
        response, -1,
        "graph_set_node_feat request requires at least 3 arguments");
    return 0;
  }
  size_t node_num = request.params(0).size() / sizeof(uint64_t);
  uint64_t *node_data = (uint64_t *)(request.params(0).c_str());
  std::vector<uint64_t> node_ids(node_data, node_data + node_num);

  std::vector<std::string> feature_names =
      paddle::string::split_string<std::string>(request.params(1), "\t");

  std::vector<std::vector<std::string>> features(
      feature_names.size(), std::vector<std::string>(node_num));

  const char *buffer = request.params(2).c_str();

  for (size_t feat_idx = 0; feat_idx < feature_names.size(); ++feat_idx) {
    for (size_t node_idx = 0; node_idx < node_num; ++node_idx) {
      size_t feat_len = *(size_t *)(buffer);
      buffer += sizeof(size_t);
      auto feat = std::string(buffer, feat_len);
      features[feat_idx][node_idx] = feat;
      buffer += feat_len;
    }
  }

  ((GraphTable *)table)->set_node_feat(node_ids, feature_names, features);

  return 0;
}

int32_t GraphBrpcService::use_neighbors_sample_cache(
    Table *table, const PsRequestMessage &request, PsResponseMessage &response,
    brpc::Controller *cntl) {
  CHECK_TABLE_EXIST(table, request, response)
  if (request.params_size() < 2) {
    set_response_code(response, -1,
                      "use_neighbors_sample_cache request requires at least 2 "
                      "arguments[cache_size, ttl]");
    return 0;
  }
  size_t size_limit = *(size_t *)(request.params(0).c_str());
  size_t ttl = *(size_t *)(request.params(1).c_str());
  ((GraphTable *)table)->make_neighbor_sample_cache(size_limit, ttl);
  return 0;
}
}  // namespace distributed
}  // namespace paddle