Merge pull request #11490 from seiriosPlus/ckpt_m2

Checkpoint M2: lookup table checkpoint

paddle/fluid/operators/CMakeLists.txt

@@ -195,7 +195,7 @@ if(WITH_DISTRIBUTE)
     endif()
 
     set(DISTRIBUTE_COMPILE_FLAGS "-Wno-non-virtual-dtor -Wno-error=non-virtual-dtor -Wno-error=delete-non-virtual-dtor")
-    foreach(dist_op "prefetch_op" "listen_and_serv_op" "send_op" "recv_op" "send_barrier_op" "fetch_barrier_op")
+    foreach(dist_op "prefetch_op" "checkpoint_notify_op" "listen_and_serv_op" "send_op" "recv_op" "send_barrier_op" "fetch_barrier_op")
         op_library(${dist_op} DEPS ${DISTRIBUTE_DEPS})
         set_source_files_properties(${dist_op}.cc PROPERTIES COMPILE_FLAGS ${DISTRIBUTE_COMPILE_FLAGS})
     endforeach()
@@ -216,7 +216,7 @@ if(WITH_DISTRIBUTE)
         set(DEPS_OPS ${DEPS_OPS} gen_nccl_id_op)
     endif()
 else()
-    set(DEPS_OPS ${DEPS_OPS}  prefetch_op recv_op listen_and_serv_op send_op send_barrier_op fetch_barrier_op gen_nccl_id_op)
+    set(DEPS_OPS ${DEPS_OPS}  checkpoint_notify_op prefetch_op recv_op listen_and_serv_op send_op send_barrier_op fetch_barrier_op gen_nccl_id_op)
 endif()
 
 op_library(cross_entropy_op DEPS cross_entropy)

paddle/fluid/operators/checkpoint_notify_op.cc

+/* Copyright (c) 2018 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 <future>  // NOLINT
+#include <ostream>
+
+#include "paddle/fluid/framework/data_type.h"
+#include "paddle/fluid/framework/lod_tensor.h"
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/detail/macros.h"
+#include "paddle/fluid/operators/send_recv_util.h"
+#include "paddle/fluid/string/printf.h"
+
+namespace paddle {
+namespace operators {
+
+class CheckpointNotifyOp : public framework::OperatorBase {
+ public:
+  CheckpointNotifyOp(const std::string& type,
+                     const framework::VariableNameMap& inputs,
+                     const framework::VariableNameMap& outputs,
+                     const framework::AttributeMap& attrs)
+      : OperatorBase(type, inputs, outputs, attrs) {}
+
+  void RunImpl(const framework::Scope& scope,
+               const platform::Place& place) const override {
+    std::vector<std::string> epmap = Attr<std::vector<std::string>>("epmap");
+    std::string dir = Attr<std::string>("dir");
+    std::string lookup_table_name = Attr<std::string>("lookup_table");
+
+    distributed::RPCClient* rpc_client =
+        distributed::RPCClient::GetInstance<RPCCLIENT_T>();
+    for (size_t i = 0; i < epmap.size(); i++) {
+      auto lookup_table_save_dir =
+          string::Sprintf("%s/%s_%d", dir, lookup_table_name, i);
+      rpc_client->AsyncCheckpointNotify(epmap[i], lookup_table_save_dir);
+      VLOG(3) << "checkpoint notify sending lookup table: " << lookup_table_name
+              << " and dir:" << dir << " to " << epmap[i];
+    }
+    rpc_client->Wait();
+  }
+};
+
+class CheckpointNotifyOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() {
+    AddAttr<std::vector<std::string>>("epmap",
+                                      "(string vector, default  127.0.0.1:6164)"
+                                      "Parameter Server endpoints in the order")
+        .SetDefault({"127.0.0.1:6164"});
+    AddAttr<std::string>(
+        "dir", "(string, default '') indicate the folder checkpoint will use");
+    AddAttr<std::string>("lookup_table",
+                         "(string, default '') the lookup table name");
+    AddComment(R"DOC(
+CheckpointNotify operator
+
+This operator will send lookup table and it's checkpoint direcoty to listen_and_serve op at
+the parameter server.
+)DOC");
+  }
+};
+
+class CheckpointNotifyOpShapeInference : public framework::InferShapeBase {
+ public:
+  void operator()(framework::InferShapeContext* ctx) const override {}
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+
+REGISTER_OPERATOR(checkpoint_notify, ops::CheckpointNotifyOp,
+                  paddle::framework::EmptyGradOpMaker,
+                  ops::CheckpointNotifyOpMaker,
+                  ops::CheckpointNotifyOpShapeInference);

paddle/fluid/operators/distributed/grpc_client.cc

@@ -239,6 +239,23 @@ void GRPCClient::AsyncSendComplete(const std::string& ep, int64_t time_out) {
   req_count_++;
 }
 
+void GRPCClient::AsyncCheckpointNotify(const std::string& ep,
+                                       const std::string& dir,
+                                       int64_t time_out) {
+  const auto ch = GetChannel(ep);
+
+  CheckpointNotifyProcessor* s = new CheckpointNotifyProcessor(ch);
+  s->Prepare(time_out);
+
+  sendrecv::VariableMessage req;
+  req.set_varname(CHECKPOINT_SAVE_MESSAGE);
+  req.set_out_varname(dir);
+
+  auto rpc = s->stub_->AsyncCheckpointNotify(s->context_.get(), req, &cq_);
+  rpc->Finish(&s->reply_, &s->status_, reinterpret_cast<void*>(s));
+  req_count_++;
+}
+
 void GRPCClient::Wait() {
   std::unique_lock<std::mutex> lk(sync_mutex_);
   sync_cond_.wait(lk, [this] { return req_count_ == 0; });

paddle/fluid/operators/distributed/grpc_client.h

@@ -171,6 +171,20 @@ class FetchBarrierProcessor : public BaseProcessor {
   std::unique_ptr<sendrecv::SendRecvService::Stub> stub_;
 };
 
+class CheckpointNotifyProcessor : public BaseProcessor {
+ public:
+  explicit CheckpointNotifyProcessor(std::shared_ptr<grpc::Channel> ch)
+      : BaseProcessor(ch) {
+    stub_ = sendrecv::SendRecvService::NewStub(ch);
+  }
+
+  virtual ~CheckpointNotifyProcessor() {}
+
+  virtual void Process() {}
+  sendrecv::VoidMessage reply_;
+  std::unique_ptr<sendrecv::SendRecvService::Stub> stub_;
+};
+
 class GRPCClient : public RPCClient {
  public:
   GRPCClient() {}
@@ -197,6 +211,9 @@ class GRPCClient : public RPCClient {
   void AsyncSendFetchBarrier(const std::string& ep,
                              int64_t time_out = FLAGS_rpc_deadline) override;
 
+  void AsyncCheckpointNotify(const std::string& ep, const std::string& dir,
+                             int64_t time_out = FLAGS_grpc_deadline) override;
+
   void Wait() override;
 
   void SendComplete() override;

paddle/fluid/operators/distributed/grpc_server.cc

@@ -200,6 +200,45 @@ class RequestPrefetch final : public RequestBase {
   framework::Scope* local_scope_;
 };
 
+class RequestCheckpointNotify final : public RequestBase {
+ public:
+  explicit RequestCheckpointNotify(GrpcService::AsyncService* service,
+                                   ::grpc::ServerCompletionQueue* cq,
+                                   RequestHandler* request_handler, int req_id)
+      : RequestBase(service, cq, request_handler, req_id), responder_(&ctx_) {
+    request_.reset(new VariableResponse(request_handler->scope(),
+                                        request_handler->dev_ctx()));
+    int method_id =
+        static_cast<int>(distributed::GrpcMethod::kCheckpointNotify);
+    service_->RequestAsyncUnary(
+        method_id, &ctx_, request_.get(), &responder_, cq_, cq_,
+        reinterpret_cast<void*>(static_cast<intptr_t>(req_id)));
+  }
+
+  virtual ~RequestCheckpointNotify() {}
+
+  std::string GetReqName() override { return request_->Varname(); }
+
+  void Process() override {
+    auto scope = request_->GetMutableLocalScope();
+
+    std::string checkpoint_notify = request_->Varname();
+    std::string checkpoint_dir = request_->OutVarname();
+
+    VLOG(4) << "RequestCheckpointNotify notify: " << checkpoint_notify
+            << ", dir: " << checkpoint_dir;
+
+    request_handler_->Handle(checkpoint_notify, scope, nullptr, nullptr,
+                             checkpoint_dir);
+    Finish(reply_, &responder_);
+  }
+
+ protected:
+  std::shared_ptr<VariableResponse> request_;
+  sendrecv::VoidMessage reply_;
+  ServerAsyncResponseWriter<sendrecv::VoidMessage> responder_;
+};
+
 void AsyncGRPCServer::WaitServerReady() {
   VLOG(4) << "AsyncGRPCServer is wait server ready";
   std::unique_lock<std::mutex> lock(this->mutex_ready_);
@@ -237,6 +276,7 @@ void AsyncGRPCServer::StartServer() {
     reqs.reserve(kRequestBufSize);
 
     for (int i = 0; i < kRequestBufSize; i++) {
+      VLOG(6) << "TryToRegisterNewOne on RPC NAME: " << rpc_name << " I: " << i;
       TryToRegisterNewOne(rpc_name, i);
     }
 
@@ -289,8 +329,8 @@ void AsyncGRPCServer::TryToRegisterNewOne(const std::string& rpc_name,
     return;
   }
 
-  VLOG(4) << "register send rpc_name:" << rpc_name
-          << ", handler:" << rpc_call_map_[kRequestSend];
+  VLOG(4) << "TryToRegisterNewOne on RPC NAME: " << rpc_name
+          << " REQ ID: " << req_id;
 
   auto& reqs = rpc_reqs_[rpc_name];
   auto& handler = rpc_call_map_[rpc_name];
@@ -303,6 +343,8 @@ void AsyncGRPCServer::TryToRegisterNewOne(const std::string& rpc_name,
     b = new RequestGet(&service_, cq.get(), handler, req_id);
   } else if (rpc_name == kRequestPrefetch) {
     b = new RequestPrefetch(&service_, cq.get(), handler, req_id);
+  } else if (rpc_name == kRequestCheckpoint) {
+    b = new RequestCheckpointNotify(&service_, cq.get(), handler, req_id);
   } else {
     PADDLE_ENFORCE(false, "not supported rpc");
   }
@@ -321,7 +363,7 @@ void AsyncGRPCServer::HandleRequest(
   while (true) {
     VLOG(4) << "HandleRequest " << rpc_name << " wait next";
     if (!cq->Next(&tag, &ok)) {
-      LOG(INFO) << "CompletionQueue " << rpc_name << " shutdown!";
+      VLOG(3) << "CompletionQueue " << rpc_name << " shutdown!";
       break;
     }
 

paddle/fluid/operators/distributed/grpc_service.h

@@ -80,10 +80,11 @@ enum class GrpcMethod {
   kSendVariable,
   kGetVariable,
   kPrefetchVariable,
+  kCheckpointNotify,
 };
 
 static const int kGrpcNumMethods =
-    static_cast<int>(GrpcMethod::kPrefetchVariable) + 1;
+    static_cast<int>(GrpcMethod::kCheckpointNotify) + 1;
 
 inline const char* GrpcMethodName(GrpcMethod id) {
   switch (id) {
@@ -93,6 +94,8 @@ inline const char* GrpcMethodName(GrpcMethod id) {
       return "/sendrecv.SendRecvService/GetVariable";
     case GrpcMethod::kPrefetchVariable:
       return "/sendrecv.SendRecvService/PrefetchVariable";
+    case GrpcMethod::kCheckpointNotify:
+      return "/sendrecv.SendRecvService/CheckpointNotify";
   }
 
   // Shouldn't be reached.

paddle/fluid/operators/distributed/request_handler.h

@@ -36,12 +36,16 @@ namespace distributed {
 constexpr char kRequestSend[] = "RequestSend";
 constexpr char kRequestGet[] = "RequestGet";
 constexpr char kRequestPrefetch[] = "RequestPrefetch";
+constexpr char kRequestCheckpoint[] = "RequestCheckpoint";
 
 #define LISTEN_TERMINATE_MESSAGE "TERMINATE@RECV"
 #define BATCH_BARRIER_MESSAGE "BATCH_BARRIER@RECV"
 #define FETCH_BARRIER_MESSAGE "FETCH_BARRIER@RECV"
 #define COMPLETE_MESSAGE "COMPLETE@RECV"
 
+#define CHECKPOINT_SAVE_MESSAGE "SAVE@CHECKPOINTNOTIFY"
+#define CHECKPOINT_LOAD_MESSAGE "LOAD@CHECKPOINTNOTIFY"
+
 class RPCServer;
 
 class RequestHandler {
@@ -69,6 +73,11 @@ class RequestHandler {
     prefetch_var_name_to_prepared_ctx_ = g;
   }
 
+  void SetCheckpointNotifyPreparedCtx(
+      std::shared_ptr<framework::ExecutorPrepareContext> g) {
+    checkpoint_prepared_ctx_ = g;
+  }
+
   // Used for async.
   void SetGradToPreparedCtx(
       std::unordered_map<
@@ -115,6 +124,8 @@ class RequestHandler {
   std::unordered_map<std::string,
                      std::shared_ptr<framework::ExecutorPrepareContext>>*
       prefetch_var_name_to_prepared_ctx_;
+  // used for checkpoint notify
+  std::shared_ptr<framework::ExecutorPrepareContext> checkpoint_prepared_ctx_;
 
   // Used for async.
   std::unordered_map<std::string,

paddle/fluid/operators/distributed/request_handler_impl.cc

@@ -22,11 +22,16 @@
 #include "paddle/fluid/framework/selected_rows.h"
 #include "paddle/fluid/operators/distributed/request_handler_impl.h"
 #include "paddle/fluid/operators/distributed/rpc_server.h"
+#include "paddle/fluid/string/printf.h"
 
 namespace paddle {
 namespace operators {
 namespace distributed {
 
+// define LOOKUP_TABLE_PATH for checkpoint notify to save lookup table variables
+// to directory specified.
+constexpr char LOOKUP_TABLE_PATH[] = "kLookupTablePath";
+
 bool RequestSendHandler::Handle(const std::string& varname,
                                 framework::Scope* scope,
                                 framework::Variable* invar,
@@ -119,6 +124,24 @@ bool RequestPrefetchHandler::Handle(const std::string& varname,
   return true;
 }
 
+bool RequestCheckpointHandler::Handle(const std::string& varname,
+                                      framework::Scope* scope,
+                                      framework::Variable* invar,
+                                      framework::Variable** outvar,
+                                      const std::string& out_var_name) {
+  PADDLE_ENFORCE(
+      checkpoint_notify_id != -1,
+      "when checkpoint_notify_id = -1, there should be no RPC invoke.");
+
+  auto* lt_var = scope->FindVar(LOOKUP_TABLE_PATH)->GetMutable<std::string>();
+  lt_var->clear();
+  lt_var->append(out_var_name);
+  VLOG(4) << "RequestCheckpointHandler update var kLookupTablePath to: "
+          << out_var_name;
+  executor_->RunPreparedContext(checkpoint_prepared_ctx_.get(), scope);
+  return true;
+}
+
 }  // namespace distributed
 }  // namespace operators
 }  // namespace paddle

paddle/fluid/operators/distributed/request_handler_impl.h

@@ -66,6 +66,21 @@ class RequestPrefetchHandler final : public RequestHandler {
               const std::string& out_var_name = "") override;
 };
 
+class RequestCheckpointHandler final : public RequestHandler {
+ public:
+  explicit RequestCheckpointHandler(bool sync_mode, int checkpoint_notify_id)
+      : RequestHandler(sync_mode) {
+    this->checkpoint_notify_id = checkpoint_notify_id;
+  }
+  virtual ~RequestCheckpointHandler() {}
+  bool Handle(const std::string& varname, framework::Scope* scope,
+              framework::Variable* var, framework::Variable** outvar,
+              const std::string& out_var_name = "") override;
+
+ private:
+  int checkpoint_notify_id;
+};
+
 }  // namespace distributed
 }  // namespace operators
 }  // namespace paddle

paddle/fluid/operators/distributed/rpc_client.h

@@ -56,6 +56,10 @@ class RPCClient {
   virtual void AsyncSendFetchBarrier(const std::string& ep,
                                      int64_t time_out = FLAGS_rpc_deadline) = 0;
 
+  virtual void AsyncCheckpointNotify(
+      const std::string& ep, const std::string& dir,
+      int64_t time_out = FLAGS_grpc_deadline) = 0;
+
   // SendComplete tells all the server that current trainer have no more data
   // to train, so that the pserver can reduce it's barrier count, and continue
   // to train with other trainers.

paddle/fluid/operators/distributed/send_recv.proto

@@ -25,6 +25,8 @@ service SendRecvService {
   rpc GetVariable(VariableMessage) returns (VariableMessage) {}
   // pre-fetch variable by given variable name and Ids
   rpc PrefetchVariable(VariableMessage) returns (VariableMessage) {}
+
+  rpc CheckpointNotify(VariableMessage) returns (VoidMessage) {}
 }
 
 // VariableMessage is serialized paddle variable message.

paddle/fluid/operators/listen_and_serv_op.cc

@@ -99,7 +99,8 @@ static int64_t GetTimestamp() {
 void ListenAndServOp::RunSyncLoop(
     framework::Executor *executor, framework::ProgramDesc *program,
     framework::Scope *recv_scope,
-    const std::vector<int> &prefetch_block_id_list) const {
+    const std::vector<int> &prefetch_block_id_list,
+    const int checkpoint_point_block_id) const {
   size_t num_blocks = program->Size();
   auto optimize_blocks =
       Attr<std::vector<framework::BlockDesc *>>(kOptimizeBlocks);
@@ -208,7 +209,7 @@ void ListenAndServOp::RunAsyncLoop(framework::Executor *executor,
 
   while (true) {
     if (rpc_service_->IsExit()) {
-      LOG(INFO) << "get exit!rpc_processor break!";
+      VLOG(4) << "get exit!rpc_processor break!";
       break;
     }
 
@@ -223,6 +224,7 @@ static void FillRequestCtx(
     std::unordered_map<std::string,
                        std::shared_ptr<framework::ExecutorPrepareContext>>
         *prefetch_ctx,
+    std::shared_ptr<framework::ExecutorPrepareContext> checkpoint_ctx,
     distributed::RPCServer *rpc_server) {
   h->SetScope(scope);
   h->SetDevCtx(dev_ctx);
@@ -230,6 +232,7 @@ static void FillRequestCtx(
   h->SetProgram(program);
   h->SetPrefetchPreparedCtx(prefetch_ctx);
   h->SetRPCServer(rpc_server);
+  h->SetCheckpointNotifyPreparedCtx(checkpoint_ctx);
 }
 
 void ListenAndServOp::RunImpl(const framework::Scope &scope,
@@ -245,9 +248,11 @@ void ListenAndServOp::RunImpl(const framework::Scope &scope,
 
   PADDLE_ENFORCE(!rpc_service_);
   std::string endpoint = Attr<std::string>("endpoint");
+  int checkpoint_block_id = Attr<int>(kCheckpointBlockId);
 
-  LOG(INFO) << "sync_mode:" << sync_mode << ", fan_in:" << fan_in
-            << ", end_point:" << endpoint;
+  VLOG(4) << "sync_mode:" << sync_mode << ", fan_in:" << fan_in
+          << ", end_point:" << endpoint
+          << ", checkpoint_block_id: " << checkpoint_block_id;
 
   rpc_service_.reset(new RPCSERVER_T(endpoint, fan_in));
 
@@ -255,6 +260,8 @@ void ListenAndServOp::RunImpl(const framework::Scope &scope,
   request_get_handler_.reset(new distributed::RequestGetHandler(sync_mode));
   request_prefetch_handler_.reset(
       new distributed::RequestPrefetchHandler(sync_mode));
+  request_checkpoint_handler_.reset(new distributed::RequestCheckpointHandler(
+      sync_mode, checkpoint_block_id));
 
   rpc_service_->RegisterRPC(distributed::kRequestSend,
                             request_send_handler_.get());
@@ -262,6 +269,8 @@ void ListenAndServOp::RunImpl(const framework::Scope &scope,
                             request_get_handler_.get());
   rpc_service_->RegisterRPC(distributed::kRequestPrefetch,
                             request_prefetch_handler_.get());
+  rpc_service_->RegisterRPC(distributed::kRequestCheckpoint,
+                            request_checkpoint_handler_.get());
 
   auto optimize_blocks =
       Attr<std::vector<framework::BlockDesc *>>(kOptimizeBlocks);
@@ -270,6 +279,13 @@ void ListenAndServOp::RunImpl(const framework::Scope &scope,
   auto *program = optimize_blocks[0]->Program();
   framework::Executor executor(dev_place);
 
+  std::shared_ptr<framework::ExecutorPrepareContext> ckpt_pre_context = nullptr;
+  if (checkpoint_block_id != -1) {
+    auto ctx = executor.Prepare(*program, checkpoint_block_id);
+    // see: https://stackoverflow.com/a/14856553
+    ckpt_pre_context = std::move(ctx);
+  }
+
   // prepare for prefetch
   std::vector<int> prefetch_block_id_list;
   std::unordered_map<int, std::string> block_id_to_prefetch_var_name;
@@ -300,13 +316,15 @@ void ListenAndServOp::RunImpl(const framework::Scope &scope,
     prefetch_var_name_to_prepared_ctx[prefetch_var_name] = prefetch_prepared[i];
   }
 
-  auto f = std::bind(FillRequestCtx, std::placeholders::_1, &recv_scope,
-                     &dev_ctx, &executor, program,
-                     &prefetch_var_name_to_prepared_ctx, rpc_service_.get());
+  auto f =
+      std::bind(FillRequestCtx, std::placeholders::_1, &recv_scope, &dev_ctx,
+                &executor, program, &prefetch_var_name_to_prepared_ctx,
+                ckpt_pre_context, rpc_service_.get());
 
   f(request_send_handler_.get());
   f(request_get_handler_.get());
   f(request_prefetch_handler_.get());
+  f(request_checkpoint_handler_.get());
 
   // start the server listening after all member initialized.
   server_thread_.reset(new std::thread(RunServer, rpc_service_));
@@ -320,7 +338,8 @@ void ListenAndServOp::RunImpl(const framework::Scope &scope,
   // Write to a file of server selected port for python use.
   SavePort();
   if (sync_mode) {
-    RunSyncLoop(&executor, program, &recv_scope, prefetch_block_id_list);
+    RunSyncLoop(&executor, program, &recv_scope, prefetch_block_id_list,
+                checkpoint_block_id);
   } else {
     RunAsyncLoop(&executor, program, &recv_scope);
   }
@@ -352,6 +371,9 @@ class ListenAndServOpMaker : public framework::OpProtoAndCheckerMaker {
         .SetDefault({});
     AddAttr<int>("Fanin", "How many clients send to this server.")
         .SetDefault(1);
+    AddAttr<int>(kCheckpointBlockId,
+                 "BolckID to run save checkpoint on pserer.")
+        .SetDefault(-1);
   }
 };
 

paddle/fluid/operators/listen_and_serv_op.h

@@ -32,6 +32,7 @@ namespace operators {
 
 constexpr char kOptimizeBlocks[] = "optimize_blocks";
 constexpr char kPrefetchVarNameToBlockId[] = "prefetch_var_name_to_block_id";
+constexpr char kCheckpointBlockId[] = "checkpint_block_id";
 
 void RunServer(std::shared_ptr<distributed::RPCServer> service);
 
@@ -47,7 +48,8 @@ class ListenAndServOp : public framework::OperatorBase {
   void RunSyncLoop(framework::Executor* executor,
                    framework::ProgramDesc* program,
                    framework::Scope* recv_scope,
-                   const std::vector<int>& prefetch_block_id_list) const;
+                   const std::vector<int>& prefetch_block_id_list,
+                   const int checkpoint_point_block_id) const;
 
   void RunAsyncLoop(framework::Executor* executor,
                     framework::ProgramDesc* program,
@@ -68,6 +70,8 @@ class ListenAndServOp : public framework::OperatorBase {
   mutable std::shared_ptr<distributed::RequestHandler> request_get_handler_;
   mutable std::shared_ptr<distributed::RequestHandler>
       request_prefetch_handler_;
+  mutable std::shared_ptr<distributed::RequestHandler>
+      request_checkpoint_handler_;
 
   mutable std::shared_ptr<std::thread> server_thread_;
 };

paddle/fluid/operators/load_op.cc

@@ -34,6 +34,8 @@ class LoadOp : public framework::OperatorBase {
     auto *dev_ctx = platform::DeviceContextPool::Instance().Get(place);
     platform::RecordEvent record_event(Type(), dev_ctx);
 
+    // FIXME(yuyang18): We save variable to local file now, but we should change
+    // it to save an output stream.
     auto filename = Attr<std::string>("file_path");
     std::ifstream fin(filename);
     PADDLE_ENFORCE(static_cast<bool>(fin), "Cannot open file %s for load op",
@@ -44,9 +46,25 @@ class LoadOp : public framework::OperatorBase {
     PADDLE_ENFORCE(out_var != nullptr, "Output variable %s cannot be found",
                    out_var_name);
 
-    auto *tensor = out_var->GetMutable<framework::LoDTensor>();
+    if (out_var->IsType<framework::LoDTensor>()) {
+      LoadLodTensor(fin, place, out_var);
+    } else if (out_var->IsType<framework::SelectedRows>()) {
+      LoadSelectedRows(fin, place, out_var);
+    } else {
+      PADDLE_ENFORCE(
+          false,
+          "Load only support LoDTensor and SelectedRows, %s has wrong type",
+          out_var_name);
+    }
+  }
 
-    DeserializeFromStream(fin, tensor, *dev_ctx);
+  void LoadLodTensor(std::istream &fin, const platform::Place &place,
+                     framework::Variable *var) const {
+    // get device context from pool
+    platform::DeviceContextPool &pool = platform::DeviceContextPool::Instance();
+    auto &dev_ctx = *pool.Get(place);
+    auto *tensor = var->GetMutable<framework::LoDTensor>();
+    DeserializeFromStream(fin, tensor, dev_ctx);
 
     auto load_as_fp16 = Attr<bool>("load_as_fp16");
     auto in_dtype = framework::ToDataType(tensor->type());
@@ -63,18 +81,27 @@ class LoadOp : public framework::OperatorBase {
                                &fp16_tensor);
 
       // reset output tensor
-      out_var->Clear();
-      tensor = out_var->GetMutable<framework::LoDTensor>();
+      var->Clear();
+      tensor = var->GetMutable<framework::LoDTensor>();
       tensor->set_lod(fp16_tensor.lod());
       tensor->ShareDataWith(fp16_tensor);
     }
   }
+
+  void LoadSelectedRows(std::istream &fin, const platform::Place &place,
+                        framework::Variable *var) const {
+    auto *selectedRows = var->GetMutable<framework::SelectedRows>();
+    // get device context from pool
+    platform::DeviceContextPool &pool = platform::DeviceContextPool::Instance();
+    auto &dev_ctx = *pool.Get(place);
+    framework::DeserializeFromStream(fin, selectedRows, dev_ctx);
+  }
 };
 
 class LoadOpProtoMaker : public framework::OpProtoAndCheckerMaker {
  public:
   void Make() override {
-    AddOutput("Out", "The tensor need to be loaded");
+    AddOutput("Out", "The LoDTensor / SelectedRows need to be loaded");
     AddAttr<bool>(
         "load_as_fp16",
         "If true, the tensor will be first loaded and then "
@@ -85,7 +112,9 @@ class LoadOpProtoMaker : public framework::OpProtoAndCheckerMaker {
                          R"(Variable will be loaded from "file_path")")
         .AddCustomChecker(
             [](const std::string &path) { return !path.empty(); });
-    AddComment("Load operator will load a tensor variable from disk file.");
+    AddComment(
+        "Load operator will load a LoDTensor / SelectedRows variable from disk "
+        "file.");
   }
 };
 }  // namespace operators

paddle/fluid/operators/save_load_op_test.cc

@@ -139,6 +139,7 @@ TEST(LoadFP16Op, CPU) {
   save_op->Run(scope, place);
 
   auto load_var = scope.Var("out_var");
+  load_var->GetMutable<paddle::framework::LoDTensor>();
   auto load_op = paddle::framework::OpRegistry::CreateOp(
       "load", {}, {{"Out", {"out_var"}}}, attrs);
   load_op->Run(scope, place);

paddle/fluid/operators/save_op.cc

@@ -22,11 +22,17 @@ limitations under the License. */
 #include "paddle/fluid/framework/framework.pb.h"
 #include "paddle/fluid/framework/lod_tensor.h"
 #include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/framework/selected_rows.h"
+#include "paddle/fluid/framework/variable.h"
 #include "paddle/fluid/platform/device_context.h"
 
 namespace paddle {
 namespace operators {
 
+// define LOOKUP_TABLE_PATH for checkpoint notify to save lookup table variables
+// to directory specified.
+constexpr char LOOKUP_TABLE_PATH[] = "kLookupTablePath";
+
 // TODO(yuyang18): If the functions below are needed by other files, move them
 // to paddle::filesystem namespace.
 constexpr char kSEP = '/';
@@ -67,9 +73,27 @@ class SaveOp : public framework::OperatorBase {
  private:
   void RunImpl(const framework::Scope &scope,
                const platform::Place &place) const override {
+    auto iname = Input("X");
+    auto *var = scope.FindVar(iname);
+    PADDLE_ENFORCE(var != nullptr, "Cannot find variable %s for save_op",
+                   iname);
+
+    if (var->IsType<framework::LoDTensor>()) {
+      SaveLodTensor(place, var);
+    } else if (var->IsType<framework::SelectedRows>()) {
+      SaveSelectedRows(scope, place, var);
+    } else {
+      PADDLE_ENFORCE(
+          false,
+          "SaveOp only support LoDTensor and SelectedRows, %s has wrong type",
+          iname);
+    }
+  }
+
+  void SaveLodTensor(const platform::Place &place,
+                     framework::Variable *var) const {
     auto filename = Attr<std::string>("file_path");
     auto overwrite = Attr<bool>("overwrite");
-    auto save_as_fp16 = Attr<bool>("save_as_fp16");
 
     if (FileExists(filename) && !overwrite) {
       PADDLE_THROW("%s is existed, cannot save to it when overwrite=false",
@@ -78,26 +102,19 @@ class SaveOp : public framework::OperatorBase {
 
     MkDirRecursively(DirName(filename).c_str());
 
-    // FIXME(yuyang18): We save variable to local file now, but we should change
-    // it to save an output stream.
-    std::ofstream fout(filename);
-    PADDLE_ENFORCE(static_cast<bool>(fout), "Cannot open %s to write",
-                   filename);
-
-    auto iname = Input("X");
-    auto *var = scope.FindVar(iname);
-    PADDLE_ENFORCE(var != nullptr, "Cannot find variable %s for save_op",
-                   iname);
-
-    PADDLE_ENFORCE(var->IsType<framework::LoDTensor>(),
-                   "SaveOp only support LoDTensor, %s has wrong type", iname);
-
     auto &tensor = var->Get<framework::LoDTensor>();
 
     // get device context from pool
     platform::DeviceContextPool &pool = platform::DeviceContextPool::Instance();
     auto &dev_ctx = *pool.Get(place);
 
+    // FIXME(yuyang18): We save variable to local file now, but we should change
+    // it to save an output stream.
+    std::ofstream fout(filename);
+    PADDLE_ENFORCE(static_cast<bool>(fout), "Cannot open %s to write",
+                   filename);
+
+    auto save_as_fp16 = Attr<bool>("save_as_fp16");
     auto in_dtype = framework::ToDataType(tensor.type());
     auto out_dtype = save_as_fp16 ? framework::proto::VarType::FP16 : in_dtype;
 
@@ -112,17 +129,43 @@ class SaveOp : public framework::OperatorBase {
     } else {
       framework::SerializeToStream(fout, tensor, dev_ctx);
     }
+    fout.close();
+  }
+
+  void SaveSelectedRows(const framework::Scope &scope,
+                        const platform::Place &place,
+                        framework::Variable *var) const {
+    auto *lt_var = scope.FindVar(LOOKUP_TABLE_PATH)->GetMutable<std::string>();
+    PADDLE_ENFORCE(
+        lt_var != nullptr,
+        "Can not find variable kLookupTablePath for SaveSelectedRows");
+    std::string filename = lt_var->data();
+    VLOG(4) << "SaveSelectedRows get File name: " << filename;
+
+    auto &selectedRows = var->Get<framework::SelectedRows>();
+
+    // get device context from pool
+    platform::DeviceContextPool &pool = platform::DeviceContextPool::Instance();
+    auto &dev_ctx = *pool.Get(place);
+
+    // FIXME(yuyang18): We save variable to local file now, but we should change
+    // it to save an output stream.
+    std::ofstream fout(filename);
+    PADDLE_ENFORCE(static_cast<bool>(fout), "Cannot open %s to write",
+                   filename);
+    framework::SerializeToStream(fout, selectedRows, dev_ctx);
+    fout.close();
   }
 };
 
 class SaveOpProtoMaker : public framework::OpProtoAndCheckerMaker {
  public:
   void Make() override {
-    AddInput("X", "(Tensor ) Input tensor to be saved");
+    AddInput("X", "(Tensor ) Input LoDTensor and SelectedRows to be saved");
     AddComment(R"DOC(
 Save operator
 
-This operator will serialize and write a tensor variable to file on disk.
+This operator will serialize and write LoDTensor / SelectedRows variable to file on disk.
 )DOC");
     AddAttr<bool>("overwrite",
                   "(boolean, default true)"
@@ -142,9 +185,26 @@ This operator will serialize and write a tensor variable to file on disk.
   }
 };
 
+class SaveOpVarTypeInference : public framework::VarTypeInference {
+ public:
+  void operator()(const framework::OpDesc &op_desc,
+                  framework::BlockDesc *block) const override {
+    auto out_var_name = op_desc.Output(LOOKUP_TABLE_PATH).front();
+    auto &out_var = block->FindRecursiveOrCreateVar(out_var_name);
+    auto var_type = framework::proto::VarType::RAW;
+    out_var.SetType(var_type);
+  }
+};
+
+class SaveOpShapeInference : public framework::InferShapeBase {
+ public:
+  void operator()(framework::InferShapeContext *ctx) const override {}
+};
 }  // namespace operators
 }  // namespace paddle
 
 namespace ops = paddle::operators;
 
-REGISTER_OPERATOR(save, ops::SaveOp, ops::SaveOpProtoMaker);
+REGISTER_OPERATOR(save, ops::SaveOp, paddle::framework::EmptyGradOpMaker,
+                  ops::SaveOpProtoMaker, ops::SaveOpVarTypeInference,
+                  ops::SaveOpShapeInference);

python/paddle/fluid/framework.py

@@ -454,7 +454,7 @@ class Operator(object):
         'rnn_memory_helper_grad', 'conditional_block', 'while', 'send', 'recv',
         'listen_and_serv', 'parallel_do', 'save_combine', 'load_combine',
         'ncclInit', 'channel_create', 'channel_close', 'channel_send',
-        'channel_recv', 'select', 'gen_nccl_id'
+        'channel_recv', 'select', 'checkpoint_notify', 'gen_nccl_id'
     }
 
     def __init__(self,
@@ -1214,6 +1214,9 @@ class Block(object):
         if var.type == core.VarDesc.VarType.STEP_SCOPES:
             ret_var = self.create_var(
                 name=var.name, persistable=var.persistable, type=var.type)
+        elif var.type == core.VarDesc.VarType.RAW:
+            ret_var = self.create_var(
+                name=var.name, persistable=var.persistable, type=var.type)
         elif var.type == core.VarDesc.VarType.SELECTED_ROWS:
             ret_var = self.create_var(
                 name=var.name,
@@ -1923,7 +1926,7 @@ def get_var(name, program=None):
     Args:
         name(str): name of the variable
         program(Program|None): program object.
-             If None, default_global_program() will be used.
+        If None, default_global_program() will be used.
 
     Returns:
         Variable

python/paddle/fluid/io.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import os
+import errno
 import time
 import shutil
 
@@ -25,7 +26,8 @@ __all__ = [
     'load_persistables', 'save_inference_model', 'load_inference_model',
     'get_inference_program', 'save_checkpoint', 'load_checkpoint',
     'clean_checkpoint', 'load_persist_vars_without_grad',
-    'save_persist_vars_without_grad', 'get_latest_checkpoint_serial'
+    'load_lookup_table_vars', 'save_persist_vars_without_grad',
+    'get_latest_checkpoint_serial'
 ]
 
 
@@ -795,6 +797,7 @@ def get_parameter_value_by_name(name, executor, program=None):
 SUCCESS_MARK_FILENAME = "_SUCCESS"
 CHECKPOINT_PREFIX = "checkpoint"
 MODEL_DIR = "__model__"
+LOOKUP_TABLE_DIR = "__lookup_table__"
 TRAINER_PREFIX = "trainer"
 CHECKPOINT_SEPARATOR = "_"
 
@@ -804,7 +807,9 @@ def save_checkpoint(executor,
                     trainer_id,
                     trainer_args=None,
                     main_program=None,
-                    max_num_checkpoints=3):
+                    max_num_checkpoints=3,
+                    lookup_table=None,
+                    ps_endpoint_list=None):
     """
     This function filters out all checkpoint variables from the give
     main_program and then saves these variables to the `checkpoint_dir` 
@@ -836,6 +841,12 @@ def save_checkpoint(executor,
         max_num_checkpoints(int): The max number of total number of existing 
             checkpoints.
             Default: 3
+        lookup_table(string|None): the lookup table name, when use distribute
+            lookup table, we can get lookup table name by DistributeTranspiler.
+            table_name 
+        ps_endpoint_list(list|None): the parameter server ip:port list.  
+            when use distribute lookup table, we can get ps_endpoint_list by 
+            distribute arguments.
 
     Returns:
         None
@@ -852,30 +863,40 @@ def save_checkpoint(executor,
             prog = fluid.default_main_program()
             trainer_args = {"epoch_id": 200,
                             "step_id": 20} # just an example
+            table_name = "share_w"
+            ps_endpoints = ["127.0.0.1:6000","127.0.0.1:6001"]
+
             fluid.io.save_checkpoint(executor=exe,
                                      checkpoint_dir=path,
                                      trainer_id=0,
                                      trainer_args=trainer_args,
                                      main_program=prog,
-                                     max_num_checkpoints=3)
+                                     max_num_checkpoints=3,
+                                     lookup_table=table_name,
+                                     ps_endpoint_list = ps_endpoints)
     """
     if checkpoint_dir is None:
         raise ValueError("'checkpoint_dir' should not be None")
+    assert checkpoint_dir
 
     if trainer_args:
         assert isinstance(trainer_args, dict)
 
-    if not os.path.isdir(checkpoint_dir):
-        os.makedirs(checkpoint_dir)
+    is_chief = trainer_id == 0
 
+    _make_chekcpoint_dirs(checkpoint_dir)
     serial = get_latest_checkpoint_serial(checkpoint_dir) + 1
     cur_dir = _get_serial_dir(checkpoint_dir, serial)
 
     save_trainer_args(cur_dir, trainer_id, trainer_args)
 
-    if trainer_id == 0:
+    if is_chief:
         save_persist_vars_without_grad(executor, cur_dir, main_program)
 
+    if is_chief and lookup_table and ps_endpoint_list:
+        save_pserver_vars_by_notify(executor, cur_dir, lookup_table,
+                                    ps_endpoint_list)
+
     _scroll_delete(checkpoint_dir, max_num_checkpoints)
 
 
@@ -942,8 +963,9 @@ def load_checkpoint(executor, checkpoint_dir, serial, main_program):
 
 def clean_checkpoint(checkpoint_dir, delete_dir=False):
     """
-    clean the checkpoint dir, when the train exits normally, the trainer will call clean_checkpoint to delete checkpoint directory saved before.
-    delete_dir only works when the directory is empty, otherwise, OSError is raised.
+    clean the checkpoint dir, when the train exits normally, 
+    the trainer will call clean_checkpoint to delete checkpoint directory saved before.
+    delete_dir only works when the directory is empty, otherwise, OSError is raised.  
 
     : param checkpoint_dir
     : param delete_dir
@@ -1009,6 +1031,56 @@ def load_persist_vars_without_grad(executor,
         filename=None)
 
 
+def load_lookup_table_vars(executor, dirname, program, pserver_id, table_name):
+    """
+    The parameter server will load lookup table's local file in 
+    selectedrows variable.
+
+    Args:
+        executor(Executor): The executor to run for loading persistable variables
+        dirname(str): The directory path
+        main_program(Program): Find the variable named table_name in main_program
+        pserver_id(int): the serial number in pserver_endpoints list
+        table_name(str): lookup table name
+
+    Returns:
+        None
+
+    Examples:
+        .. code-block:: python
+
+            exe = fluid.Executor(fluid.CPUPlace())
+            dirname = "./checkpoints/checkpoint_9/__model__"
+            prog = fluid.default_main_program()
+            pserver_id = 1
+            table_name = "share_w"
+            fluid.io.load_lookup_table_vars(executor=exe,
+                    dirname=dirname, program=prog, pserver_id=pserver_id,
+                    table_name=table_name)
+    """
+
+    for var in program.list_vars():
+        if var.name == table_name:
+            lookup_table_var = var
+            break
+
+    assert lookup_table_var is not None
+
+    lookup_table_dir = os.path.join(dirname, LOOKUP_TABLE_DIR)
+    table_file = table_name + CHECKPOINT_SEPARATOR + str(pserver_id)
+
+    load_prog = Program()
+    load_block = load_prog.global_block()
+
+    load_block.append_op(
+        type='load',
+        inputs={},
+        outputs={'Out': [lookup_table_var]},
+        attrs={'file_path': os.path.join(lookup_table_dir, table_file)})
+
+    executor.run(load_prog)
+
+
 def save_persist_vars_without_grad(executor, dirname, program):
     """
     This function filters out all checkpoint variables from the give
@@ -1055,6 +1127,54 @@ def save_persist_vars_without_grad(executor, dirname, program):
     _write_success(cur_dir)
 
 
+def save_pserver_vars_by_notify(executor, dirname, lookup_table,
+                                ps_endpoint_list):
+    """
+    This function will send checkpoint notify message from Trainer 0
+    to all the pservers.
+    The checkpoint notify message contains lookup table name, 
+    the absolute path on pserver to save lookup_table.
+
+    Args:
+        executor(Executor): The executor to run for send checkpoint notify.
+        dirname(str): The folder where to save checkpoints.
+        lookup_table(string): the lookup table name, when use distribute
+            lookup table, we can get lookup table name by DistributeTranspiler.
+            table_name 
+        ps_endpoint_list(list): the parameter server ip:port list.  
+            when use distribute lookup table, we can get ps_endpoint_list by 
+            distribute arguments.
+    Return:
+        None
+    
+    Examples:
+        .. code-block:: python
+
+            exe = fluid.Executor(fluid.CPUPlace())
+            param_path = "./my_paddle_model"
+            prog = fluid.default_main_program()
+            table_name = "share_w"
+            ps_endpoints = ["127.0.0.1:6000","127.0.0.1:6001"]
+
+            fluid.io.save_pserver_vars_by_notify(executor=exe,
+                    dirname=param_path, lookup_table=table_name, 
+                    ps_endpoint_list=ps_endpoints)
+    """
+    cur_dir = _get_lookuptable_dir(dirname)
+
+    checkpoint_notify_program = Program()
+    checkpoint_notify_block = checkpoint_notify_program.global_block()
+
+    attrs = {}
+    attrs['epmap'] = ps_endpoint_list
+    attrs['dir'] = cur_dir
+    attrs['lookup_table'] = lookup_table
+
+    checkpoint_notify_block.append_op(
+        type='checkpoint_notify', inputs={}, outputs={}, attrs=attrs)
+    executor.run(checkpoint_notify_program)
+
+
 def save_trainer_args(dirname, trainer_id, trainer_args):
     assert isinstance(trainer_args, dict)
 
@@ -1068,6 +1188,29 @@ def save_trainer_args(dirname, trainer_id, trainer_args):
 
 
 def load_trainer_args(checkpoint_dir, serial, trainer_id, trainer_args):
+    """
+    trainer will load some args from it's independent directory, 
+    such as epoch_id and step_id.
+
+    Args:
+        checkpoint_dir(str): The folder where all checkpoints are.
+        serial(int): The serial of checkpoint you would like to load.
+        trainer_id(int): current trainer id.
+        trainer_args(list): list about load trainer args
+    Return:
+        None
+
+    Examples:
+        .. code-block:: python
+
+            param_path = "./checkpoint/"
+            serial = 7
+            trainer_id = 2
+            trainer_args = ["epoch_id", "step_id"]
+
+            fluid.io.load_trainer_args(checkpoint_dir=param_path, serial=serial,
+            trainer_id=trainer_id, trainer_args=trainer_args)
+    """
     assert isinstance(trainer_args, list)
 
     cur_dir = _get_serial_dir(checkpoint_dir, serial)
@@ -1088,7 +1231,7 @@ def _is_checkpoint_var(var):
     the checkpoint will not save or load all the variables.
     var type is FEED_MINIBATCH/FETCH_LIST/RAW or var name ends with @GRAD are discarded.
 
-    : param var
+    : param var(Variable)
     """
     if var.desc.type() == core.VarDesc.VarType.FEED_MINIBATCH or \
             var.desc.type() == core.VarDesc.VarType.FETCH_LIST or \
@@ -1108,6 +1251,23 @@ def _is_checkpoint_var(var):
     return var.persistable
 
 
+def _make_chekcpoint_dirs(dirs):
+    """
+    _make_chekcpoint_dirs will makdir local directory directly, when the directory is exist, it will igore it.
+    """
+    assert dirs is not None
+
+    if os.path.isfile(dirs):
+        raise OSError(errno.ENOTDIR, "dirs path shoule be a Directory.", dirs)
+
+    if not os.path.isdir(dirs):
+        try:
+            os.makedirs(dirs)
+        except OSError as err:
+            if err.errno != errno.EEXIST:
+                raise err
+
+
 def _get_dir_serial(dirname):
     _, serial = dirname.split(CHECKPOINT_SEPARATOR)
 
@@ -1121,29 +1281,27 @@ def _get_dir_serial(dirname):
 def _get_serial_dir(dirname, serial):
     serial_folder = CHECKPOINT_PREFIX + CHECKPOINT_SEPARATOR + str(serial)
     serial_dir = os.path.join(dirname, serial_folder)
-
-    if not os.path.isdir(serial_dir):
-        os.makedirs(serial_dir)
+    _make_chekcpoint_dirs(serial_dir)
 
     return serial_dir
 
 
 def _get_model_dir(dirname):
     model_dir = os.path.join(dirname, MODEL_DIR)
+    _make_chekcpoint_dirs(model_dir)
+    return model_dir
 
-    if not os.path.isdir(model_dir):
-        os.makedirs(model_dir)
 
-    return model_dir
+def _get_lookuptable_dir(dirname):
+    lookuptable_dir = os.path.join(dirname, LOOKUP_TABLE_DIR)
+    _make_chekcpoint_dirs(lookuptable_dir)
+    return lookuptable_dir
 
 
 def _get_trainer_dir(dirname, trainer_id):
     trainer_folder = TRAINER_PREFIX + CHECKPOINT_SEPARATOR + str(trainer_id)
     trainer_dir = os.path.join(dirname, trainer_folder)
-
-    if not os.path.isdir(trainer_dir):
-        os.makedirs(trainer_dir)
-
+    _make_chekcpoint_dirs(trainer_dir)
     return trainer_dir
 
 
@@ -1162,7 +1320,11 @@ def _scroll_delete(dirname, max_num_checkpoints=3):
     serials = serials[max_num_checkpoints:]
     for serial in serials:
         cur_dir = _get_serial_dir(dirname, serial)
-        shutil.rmtree(cur_dir)
+        try:
+            shutil.rmtree(cur_dir)
+        except OSError as err:
+            if err.errno != errno.ENOENT:
+                raise err
 
 
 def _write_success(dirname):

python/paddle/fluid/trainer.py

@@ -119,27 +119,20 @@ class CheckpointConfig(object):
                  max_num_checkpoints=3,
                  epoch_interval=1,
                  step_interval=10):
-        if checkpoint_dir is None:
-            self.checkpoint_dir = os.getcwd()
-        else:
-            self.checkpoint_dir = checkpoint_dir
-
-        self.max_num_checkpoints = max_num_checkpoints
-
-        if epoch_interval < 1:
-            self.epoch_interval = 1
-        else:
-            self.epoch_interval = epoch_interval
 
-        if step_interval < 1:
-            self.step_interval = 10
-        else:
-            self.step_interval = step_interval
+        assert epoch_interval >= 1
+        assert step_interval >= 1
 
+        self.checkpoint_dir = checkpoint_dir \
+            if checkpoint_dir is not None else os.getcwd()
+        self.max_num_checkpoints = max_num_checkpoints
+        self.epoch_interval = epoch_interval
+        self.step_interval = step_interval
         self.epoch_id = 0
         self.step_id = 0
         self.load_serial = None
-        self.is_pserver = False
+        self.pserver_id = None
+        self.lookup_table_name = None
 
 
 def check_and_get_place(place):
@@ -290,13 +283,20 @@ class Trainer(object):
                                    self.checkpoint_cfg.load_serial,
                                    self.startup_program)
 
-            if not self.checkpoint_cfg.is_pserver:
-                epoch_id, step_id = io.load_trainer_args(
-                    self.checkpoint_cfg.checkpoint_dir,
-                    self.checkpoint_cfg.load_serial, self.trainer_id,
-                    self._get_checkpoint_load_args())
-                self.checkpoint_cfg.epoch_id = int(epoch_id)
-                self.checkpoint_cfg.step_id = int(step_id)
+                if not self.checkpoint_cfg.pserver_id:
+                    epoch_id, step_id = io.load_trainer_args(
+                        self.checkpoint_cfg.checkpoint_dir,
+                        self.checkpoint_cfg.load_serial, self.trainer_id,
+                        self._get_checkpoint_load_args())
+                    self.checkpoint_cfg.epoch_id = int(epoch_id)
+                    self.checkpoint_cfg.step_id = int(step_id)
+                else:
+                    if self.checkpoint_cfg.lookup_table_name:
+                        io.load_lookup_table_vars(
+                            exe, self.checkpoint_cfg.checkpoint_dir,
+                            self.startup_program,
+                            self.checkpoint_cfg.pserver_id,
+                            self.checkpoint_cfg.lookup_table_name)
 
         if param_path and os.path.isdir(param_path):
             # load params from param_path into scope
@@ -366,7 +366,10 @@ class Trainer(object):
                 self.trainer_id, pservers=pserver_endpoints, trainers=trainers)
             if training_role == "PSERVER":
                 if self.checkpoint_cfg:
-                    self.is_pserver = True
+                    pserver_id = eplist.index(current_endpoint)
+                    self.checkpoint_cfg.pserver_id = pserver_id
+                    if t.has_distributed_lookup_table:
+                        self.checkpoint_cfg.lookup_table_name = t.table_name
 
                 self.train_program = t.get_pserver_program(current_endpoint)
                 self.startup_program = t.get_startup_program(current_endpoint,
@@ -566,7 +569,8 @@ class Trainer(object):
     def _save_checkpoint(self, epoch_id, step_id):
         assert self.checkpoint_cfg
 
-        if epoch_id % self.checkpoint_cfg.epoch_interval == 0 and step_id % self.checkpoint_cfg.step_interval == 0:
+        if epoch_id % self.checkpoint_cfg.epoch_interval == 0 \
+            and step_id % self.checkpoint_cfg.step_interval == 0:
             exe = executor.Executor(self.place)
             io.save_checkpoint(
                 executor=exe,

python/paddle/fluid/transpiler/distribute_transpiler.py

@@ -471,6 +471,8 @@ class DistributeTranspiler(object):
                 pserver_index, pserver_program, pre_block_idx, grad_to_block_id)
             prefetch_var_name_to_block_id = self._create_prefetch_block(
                 pserver_index, pserver_program, table_opt_block)
+            checkpoint_block_id = self._create_checkpoint_save_block(
+                pserver_program, table_opt_block.idx)
 
         # NOTE: if has_distributed_lookup_table is False, then prefetch_block will
         # not be executed, so it's safe to use optimize_block to hold the place
@@ -489,6 +491,7 @@ class DistributeTranspiler(object):
         if len(prefetch_var_name_to_block_id) > 0:
             attrs['prefetch_var_name_to_block_id'] \
                 = prefetch_var_name_to_block_id
+            attrs['checkpint_block_id'] = checkpoint_block_id
 
         # step5 append the listen_and_serv op
         pserver_program.global_block().append_op(
@@ -910,6 +913,27 @@ class DistributeTranspiler(object):
 
         return table_opt_block
 
+    def _create_checkpoint_save_block(self, pserver_program, pre_block_idx):
+        """
+        create a new block to handle save checkpoint.
+        """
+        import os
+
+        pserver_program.global_block().create_var(
+            name="kLookupTablePath",
+            persistable=True,
+            type=core.VarDesc.VarType.RAW)
+
+        checkpoint_save_block = pserver_program.create_block(pre_block_idx)
+        # this 'file_path' do not be used in save lookup table variable
+        checkpoint_save_block.append_op(
+            type='save',
+            inputs={'X': [self.table_name]},
+            outputs={},
+            attrs={'file_path': "none"})
+
+        return checkpoint_save_block.idx
+
     def _create_vars_from_blocklist(self,
                                     program,
                                     block_list,