diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6c6173ccce4812b14dc66ddef93e98c82f8fdce8..7f0942698a48b85605cd2f5d8d498c770fd2303d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -72,7 +72,7 @@ add_executable(vl_test
         ${PROJECT_SOURCE_DIR}/visualdl/utils/concurrency.h
         ${PROJECT_SOURCE_DIR}/visualdl/utils/filesystem.h
         )
-target_link_libraries(vl_test sdk storage entry tablet im gtest glog protobuf gflags pthread eigen3)
+target_link_libraries(vl_test sdk storage binary_record entry tablet im gtest glog protobuf gflags pthread eigen3)
 enable_testing ()
 add_test(NAME vstest COMMAND ./vl_test)
 endif(NOT ON_RELEASE)
diff --git a/demo/pytorch/pytorch_cifar10.py b/demo/pytorch/pytorch_cifar10.py
index e68f1aed192dd0596babb0f91075b73a5afff3f8..4915a932ce792be5235de22856cb9e77500ee10a 100644
--- a/demo/pytorch/pytorch_cifar10.py
+++ b/demo/pytorch/pytorch_cifar10.py
@@ -43,7 +43,7 @@ def imshow(img):
     fig.savefig('out' + str(np.random.randint(0, 10000)) + '.pdf')
 
 
-logdir = "/workspace"
+logdir = "./workspace"
 logger = LogWriter(logdir, sync_cycle=100)
 
 # mark the components with 'train' label.
diff --git a/requirements.txt b/requirements.txt
index 927faa9026267ebabd40ab88664f8eb444ef52da..ba8ef6a7f34ed03da88e2587662c41a6306ef1c9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,5 @@ sphinx-rtd-theme==0.2.4
 flake8==3.5.0
 Pillow==5.0.0
 pre-commit==1.5.1
+flask==0.12.2
+protobuf==3.5.1
diff --git a/visualdl/logic/CMakeLists.txt b/visualdl/logic/CMakeLists.txt
index bcabd3b529eedd3ee3bd89898f1a286f18acc8c4..afb353153d524b3bb500bb92595ac9caff9b1f8d 100644
--- a/visualdl/logic/CMakeLists.txt
+++ b/visualdl/logic/CMakeLists.txt
@@ -15,7 +15,7 @@
 add_library(im ${PROJECT_SOURCE_DIR}/visualdl/logic/im.cc)
 add_library(sdk ${PROJECT_SOURCE_DIR}/visualdl/logic/sdk.cc ${PROJECT_SOURCE_DIR}/visualdl/utils/image.h)
 add_dependencies(im storage_proto)
-add_dependencies(sdk entry storage storage_proto eigen3)
+add_dependencies(sdk entry binary_record storage storage_proto eigen3)
 
 ## pybind
 set(OPTIONAL_LINK_FLAGS)
@@ -28,10 +28,10 @@ add_library(core SHARED ${PROJECT_SOURCE_DIR}/visualdl/logic/pybind.cc)
 
 if (NOT ON_RELEASE)
   add_dependencies(core pybind python im entry tablet storage sdk protobuf glog eigen3)
-  target_link_libraries(core PRIVATE pybind entry python im tablet storage sdk protobuf glog ${OPTIONAL_LINK_FLAGS})
+  target_link_libraries(core PRIVATE pybind entry binary_record python im tablet storage sdk protobuf glog ${OPTIONAL_LINK_FLAGS})
 else()
   add_dependencies(core pybind python im entry tablet storage sdk protobuf eigen3)
-  target_link_libraries(core PRIVATE pybind entry python im tablet storage sdk protobuf ${OPTIONAL_LINK_FLAGS})
+  target_link_libraries(core PRIVATE pybind entry binary_record python im tablet storage sdk protobuf ${OPTIONAL_LINK_FLAGS})
 endif()
 set_target_properties(core PROPERTIES PREFIX "" SUFFIX ".so")
 
diff --git a/visualdl/logic/sdk.cc b/visualdl/logic/sdk.cc
index 94dce5c2bad3e200d8d08bb7294d6614a9b11f20..3edc8c27666676fc911e621e66e293cf142eba2d 100644
--- a/visualdl/logic/sdk.cc
+++ b/visualdl/logic/sdk.cc
@@ -244,7 +244,7 @@ void Image::SetSample(int index,
     CHECK_EQ(std::remove(old_path.c_str()), 0) << "delete old binary record "
                                                << old_path << " failed";
   }
-  entry.SetRaw(brcd.hash());
+  entry.SetRaw(brcd.filename());
 
   static_assert(
       !is_same_type<value_t, shape_t>::value,
@@ -268,10 +268,10 @@ ImageReader::ImageRecord ImageReader::record(int offset, int index) {
   ImageRecord res;
   auto record = reader_.record(offset);
   auto entry = record.data(index);
-  auto data_hash = entry.GetRaw();
+  auto filename = entry.GetRaw();
   CHECK(!g_log_dir.empty())
       << "g_log_dir should be set in LogReader construction";
-  BinaryRecordReader brcd(GenBinaryRecordDir(g_log_dir), data_hash);
+  BinaryRecordReader brcd(GenBinaryRecordDir(g_log_dir), filename);
 
   std::transform(brcd.data.begin(),
                  brcd.data.end(),
diff --git a/visualdl/storage/CMakeLists.txt b/visualdl/storage/CMakeLists.txt
index 51a0b415d968a29b69777ba64c2c705d7b8192d8..0a788ae7ebb7eeececbfd2985f21bf8feee847ec 100644
--- a/visualdl/storage/CMakeLists.txt
+++ b/visualdl/storage/CMakeLists.txt
@@ -7,9 +7,10 @@ add_dependencies(storage_proto protobuf)
 add_library(entry entry.cc entry.h ${PROTO_SRCS} ${PROTO_HDRS})
 add_library(tablet tablet.cc tablet.h ${PROTO_SRCS} ${PROTO_HDRS})
 add_library(record record.cc record.h ${PROTO_SRCS} ${PROTO_HDRS})
+add_library(binary_record binary_record.cc binary_record.h ${PROTO_SRCS} ${PROTO_HDRS})
 add_library(storage storage.cc storage.h ${PROTO_SRCS} ${PROTO_HDRS})
 
 add_dependencies(entry storage_proto im)
 add_dependencies(record storage_proto entry)
 add_dependencies(tablet storage_proto)
-add_dependencies(storage storage_proto record tablet entry)
+add_dependencies(storage storage_proto record binary_record tablet entry)
diff --git a/visualdl/storage/binary_record.cc b/visualdl/storage/binary_record.cc
new file mode 100644
index 0000000000000000000000000000000000000000..29e3bdd6cf16795680efd8c5dfc667562c324dab
--- /dev/null
+++ b/visualdl/storage/binary_record.cc
@@ -0,0 +1,21 @@
+/* Copyright (c) 2017 VisualDL Authors. All Rights Reserve.
+
+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 "visualdl/storage/binary_record.h"
+
+namespace visualdl {
+
+int BinaryRecord::counter_ = 0;
+
+}  // namespace visualdl
diff --git a/visualdl/storage/binary_record.h b/visualdl/storage/binary_record.h
index 529bd95e96b528f93bd4a7fb2de4f61a5c9498f7..8b8c42c6b5760b5b0c7bb983fec05df71ec87526 100644
--- a/visualdl/storage/binary_record.h
+++ b/visualdl/storage/binary_record.h
@@ -17,6 +17,7 @@ limitations under the License. */
 
 #include <fstream>
 #include <functional>
+#include <sstream>
 
 #include "visualdl/utils/filesystem.h"
 
@@ -32,12 +33,10 @@ static std::string GenBinaryRecordDir(const std::string& dir) {
 // directly in protobuf. So a simple binary storage is used to serialize images
 // to disk.
 struct BinaryRecord {
-  std::hash<std::string> hasher;
-
   BinaryRecord(const std::string dir, std::string&& data)
       : data_(data), dir_(dir) {
-    hash_ = std::to_string(hasher(data));
-    path_ = dir + "/" + hash();
+    filename_ = GenerateFileName();
+    path_ = dir + "/" + filename_;
   }
 
   const std::string& path() { return path_; }
@@ -52,42 +51,58 @@ struct BinaryRecord {
     file.write(data_.data(), data_.size());
   }
 
-  const std::string& hash() { return hash_; }
+  static std::string GenerateFileName() {
+    std::stringstream ss;
+    ss << counter_++;
+    return ss.str();
+  }
+
+  const std::string& filename() { return filename_; }
 
 private:
   std::string dir_;
   std::string path_;
   std::string data_;
-  std::string hash_;
+  std::string filename_;
+  static int counter_;
 };
 
 struct BinaryRecordReader {
   std::string data;
-  std::hash<std::string> hasher;
 
-  BinaryRecordReader(const std::string& dir, const std::string& hash)
-      : dir_(dir), hash_(hash) {
+  BinaryRecordReader(const std::string& dir, const std::string& filename)
+      : dir_(dir), filename_(filename) {
     fromfile();
   }
-  std::string hash() { return std::to_string(hasher(data)); }
+
+  const std::string& filename() { return filename_; }
 
 protected:
   void fromfile() {
-    std::string path = dir_ + "/" + hash_;
-    std::ifstream file(path, file.binary);
-    CHECK(file.is_open()) << " failed to open file " << path;
-
-    size_t size;
-    file.read(reinterpret_cast<char*>(&size), sizeof(size_t));
-    data.resize(size);
-    file.read(&data[0], size);
-
-    CHECK_EQ(hash(), hash_) << "data broken: " << path;
+    // filename_ can be empty if a user stops training abruptly.  In that case,
+    // we shouldn't load the file. The server will hang if we try to load the
+    // empty file. For now we don't throw an assert since it causes performance
+    // problems on the server.
+    // TODO(thuan): Update SDK.cc to not add image record if user stops training
+    // abruptly and no filename_ is set.
+    // TODO(thuan): Optimize visualDL server retry logic when a request fails.
+    // Currently if SDK call fails, server will issue multiple retries,
+    // which impacts performance.
+    if (!filename_.empty()) {
+      std::string path = dir_ + "/" + filename_;
+      std::ifstream file(path, file.binary);
+      CHECK(file.is_open()) << " failed to open file " << path;
+
+      size_t size;
+      file.read(reinterpret_cast<char*>(&size), sizeof(size_t));
+      data.resize(size);
+      file.read(&data[0], size);
+    }
   }
 
 private:
   std::string dir_;
-  std::string hash_;
+  std::string filename_;
 };
 
 }  // namespace visualdl
diff --git a/visualdl/storage/test_binary_record.cc b/visualdl/storage/test_binary_record.cc
index c51dcbeea909161ae61e34bf516598d52a5d9194..52ea6cbb3102603819a9f258561d6163748482cc 100644
--- a/visualdl/storage/test_binary_record.cc
+++ b/visualdl/storage/test_binary_record.cc
@@ -23,7 +23,7 @@ TEST(BinaryRecord, init) {
   BinaryRecord rcd("./", std::move(message));
   rcd.tofile();
 
-  BinaryRecordReader reader("./", rcd.hash());
+  BinaryRecordReader reader("./", rcd.filename());
   LOG(INFO) << reader.data;
   ASSERT_EQ(reader.data, "hello world");
 }