diff --git a/doc/api/v2/config/layer.rst b/doc/api/v2/config/layer.rst
index f273474e6316d3af272acfbb9b5d6c089fe5f4bb..c7b017bc07b25bc606fd838a5fb9d3715f4faecb 100644
--- a/doc/api/v2/config/layer.rst
+++ b/doc/api/v2/config/layer.rst
@@ -453,6 +453,14 @@ eos
 ..  autoclass:: paddle.v2.layer.eos
     :noindex:
 
+Miscs
+=====
+
+dropout
+--------------
+..  autoclass:: paddle.v2.layer.dropout
+    :noindex:
+
 Activation with learnable parameter
 ===================================
 
@@ -460,4 +468,3 @@ prelu
 --------
 ..  autoclass:: paddle.v2.layer.prelu
     :noindex:
-
diff --git a/doc/api/v2/config/networks.rst b/doc/api/v2/config/networks.rst
index b2a617fff134035c04eeabbbaf6d9cbe2a525f1c..6e813ab1a820d068ea3e54cad6178f1cf928eadc 100644
--- a/doc/api/v2/config/networks.rst
+++ b/doc/api/v2/config/networks.rst
@@ -125,11 +125,3 @@ simple_attention
     :members: simple_attention
     :noindex:
 
-Miscs
-=====
-
-dropout_layer
---------------
-..  automodule:: paddle.v2.networks
-    :members: dropout_layer
-    :noindex:
diff --git a/paddle/CMakeLists.txt b/paddle/CMakeLists.txt
index 9898dc083ebb1783a0e2ddd12afaa9c3d5a79e98..47ca1833967ee705d6558b1dad06a6335b30f03a 100644
--- a/paddle/CMakeLists.txt
+++ b/paddle/CMakeLists.txt
@@ -8,6 +8,7 @@ add_subdirectory(gserver)
 add_subdirectory(pserver)
 add_subdirectory(trainer)
 add_subdirectory(scripts)
+add_subdirectory(strings)
 
 # Do not build go directory until go cmake is working smoothly.
 # if(CMAKE_Go_COMPILER)
diff --git a/paddle/api/CMakeLists.txt b/paddle/api/CMakeLists.txt
index e147659566dba6cfbfd677e3b616bdaa4a73485c..071bc36c2ded51ba977350aeae15f6d244cea5be 100644
--- a/paddle/api/CMakeLists.txt
+++ b/paddle/api/CMakeLists.txt
@@ -41,6 +41,7 @@ SET(SWIG_MODULE_swig_paddle_EXTRA_DEPS
     paddle_network
     paddle_proto
     ${external_project_dependencies}
+    ${RDMA_LIBS}
 )
 
 IF(APPLE)
@@ -73,6 +74,7 @@ SWIG_LINK_LIBRARIES(swig_paddle
     ${CMAKE_DL_LIBS}
     ${EXTERNAL_LIBS}
     ${CMAKE_THREAD_LIBS_INIT}
+    ${RDMA_LD_FLAGS}
     ${START_END}
 )
 
diff --git a/paddle/strings/CMakeLists.txt b/paddle/strings/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..4e55eecd484c0e218ecd51bbd19b3eb4f6f92a25
--- /dev/null
+++ b/paddle/strings/CMakeLists.txt
@@ -0,0 +1,2 @@
+cc_library(stringpiece SRCS stringpiece.cc)
+cc_test(stringpiece_test SRCS stringpiece_test.cc DEPS stringpiece glog gflags)
diff --git a/paddle/strings/stringpiece.cc b/paddle/strings/stringpiece.cc
new file mode 100644
index 0000000000000000000000000000000000000000..415b3558d5dfffde26275bcb16ea3922424ca9f3
--- /dev/null
+++ b/paddle/strings/stringpiece.cc
@@ -0,0 +1,141 @@
+/*
+  Copyright (c) 2016 PaddlePaddle 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 "paddle/strings/stringpiece.h"
+
+#include <string.h>
+
+#include <algorithm>
+#include <iosfwd>
+#include <stdexcept>
+
+namespace paddle {
+
+StringPiece::StringPiece() : data_(NULL), size_(0) {}
+
+StringPiece::StringPiece(const char* d, size_t n) : data_(d), size_(n) {
+  if (d == NULL && n != 0)
+    throw std::invalid_argument(
+        "StringPiece requires len to be 0 for NULL data");
+}
+
+StringPiece::StringPiece(const char* s) : data_(s) {
+  size_ = (s == NULL) ? 0 : strlen(s);
+}
+
+StringPiece::StringPiece(const std::string& s)
+    : data_(s.data()), size_(s.size()) {}
+
+char StringPiece::operator[](size_t n) const {
+  if (n >= len())
+    throw std::invalid_argument("index out of StringPiece length");
+  return data_[n];
+}
+
+int Compare(StringPiece a, StringPiece b) {
+  const size_t min_len = (a.len() < b.len()) ? a.len() : b.len();
+  int r = memcmp(a.data(), b.data(), min_len);
+  if (r == 0) {
+    if (a.len() < b.len())
+      return -1;
+    else if (a.len() > b.len())
+      return 1;
+  }
+  return r;
+}
+
+bool operator==(StringPiece x, StringPiece y) {
+  return ((x.len() == y.len()) &&
+          (x.data() == y.data() || memcmp(x.data(), y.data(), x.len()) == 0));
+}
+
+bool operator!=(StringPiece x, StringPiece y) { return !(x == y); }
+
+bool operator<(StringPiece x, StringPiece y) { return Compare(x, y) < 0; }
+bool operator>(StringPiece x, StringPiece y) { return Compare(x, y) > 0; }
+
+bool operator<=(StringPiece x, StringPiece y) { return Compare(x, y) <= 0; }
+bool operator>=(StringPiece x, StringPiece y) { return Compare(x, y) >= 0; }
+
+bool HasPrefix(StringPiece s, StringPiece x) {
+  return ((s.len() >= x.len()) && (memcmp(s.data(), x.data(), x.len()) == 0));
+}
+
+bool HasSuffix(StringPiece s, StringPiece x) {
+  return ((s.len() >= x.len()) &&
+          (memcmp(s.data() + (s.len() - x.len()), x.data(), x.len()) == 0));
+}
+
+StringPiece SkipPrefix(StringPiece s, size_t n) {
+  if (n > s.len())
+    throw std::invalid_argument("Skip distance larger than StringPiece length");
+  return StringPiece(s.data() + n, s.len() - n);
+}
+
+StringPiece SkipSuffix(StringPiece s, size_t n) {
+  if (n > s.len())
+    throw std::invalid_argument("Skip distance larger than StringPiece length");
+  return StringPiece(s.data(), s.len() - n);
+}
+
+StringPiece TrimPrefix(StringPiece s, StringPiece x) {
+  return HasPrefix(s, x) ? SkipPrefix(s, x.len()) : s;
+}
+
+StringPiece TrimSuffix(StringPiece s, StringPiece x) {
+  return HasSuffix(s, x) ? SkipSuffix(s, x.len()) : s;
+}
+
+bool Contains(StringPiece s, StringPiece sub) {
+  return std::search(s.begin(), s.end(), sub.begin(), sub.end()) != s.end();
+}
+
+size_t Index(StringPiece s, StringPiece sub) {
+  auto e = std::search(s.begin(), s.end(), sub.begin(), sub.end());
+  return e != s.end() ? e - s.data() : StringPiece::npos;
+}
+
+size_t Find(StringPiece s, char c, size_t pos) {
+  if (pos >= s.len()) {
+    return StringPiece::npos;
+  }
+  const char* result =
+      reinterpret_cast<const char*>(memchr(s.data() + pos, c, s.len() - pos));
+  return result != nullptr ? result - s.data() : StringPiece::npos;
+}
+
+size_t RFind(StringPiece s, char c, size_t pos) {
+  if (s.len() == 0) return StringPiece::npos;
+  for (const char* p = s.data() + std::min(pos, s.len() - 1); p >= s.data();
+       p--) {
+    if (*p == c) {
+      return p - s.data();
+    }
+  }
+  return StringPiece::npos;
+}
+
+StringPiece SubStr(StringPiece s, size_t pos, size_t n) {
+  if (pos > s.len()) pos = s.len();
+  if (n > s.len() - pos) n = s.len() - pos;
+  return StringPiece(s.data() + pos, n);
+}
+
+std::ostream& operator<<(std::ostream& o, StringPiece piece) {
+  return o << piece.ToString();
+}
+
+}  // namespace paddle
diff --git a/paddle/strings/stringpiece.h b/paddle/strings/stringpiece.h
new file mode 100644
index 0000000000000000000000000000000000000000..89aa084a2920c6f372b771e0e407b64728ea69e4
--- /dev/null
+++ b/paddle/strings/stringpiece.h
@@ -0,0 +1,104 @@
+/*
+  Copyright (c) 2016 PaddlePaddle 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.
+*/
+
+#pragma once
+
+#include <string>
+
+namespace paddle {
+
+// StringPiece points into a std::string object but doesn't own the
+// string.  It is for efficient access to strings.  Like Go's string
+// type.  Not that StringPiece doesn't mutate the underlying string,
+// so it is thread-safe given that the underlying string doesn't
+// change.  Because StringPiece contains a little data members, and
+// its syntax is simple as it doesn't own/manage the string, it is
+// cheap to construct StringPieces and pass them around.
+class StringPiece {
+public:
+  static const size_t npos = static_cast<size_t>(-1);
+
+  // We provide non-explicit singleton constructors so users can
+  // pass in a "const char*" or a "string" wherever a "StringPiece"
+  // is expected.  These contructors ensure that if data_ is NULL,
+  // size_ is 0.
+  StringPiece();
+  StringPiece(const char* d, size_t n);
+  StringPiece(const char* d);
+  StringPiece(const std::string& s);
+
+  const char* data() const { return data_; }
+  size_t len() const { return size_; }
+
+  char operator[](size_t n) const;
+
+  // StringPiece doesn't own the string, so both iterator and const
+  // iterator are const char* indeed.
+  typedef const char* const_iterator;
+  typedef const char* iterator;
+  iterator begin() const { return data_; }
+  iterator end() const { return data_ + size_; }
+
+  // Return a string that contains the copy of the referenced data.
+  std::string ToString() const { return std::string(data_, size_); }
+
+private:
+  const char* data_;
+  size_t size_;
+
+  // Intentionally copyable
+};
+
+int Compare(StringPiece a, StringPiece b);
+
+bool operator==(StringPiece x, StringPiece y);
+bool operator!=(StringPiece x, StringPiece y);
+bool operator<(StringPiece x, StringPiece y);
+bool operator>(StringPiece x, StringPiece y);
+bool operator<=(StringPiece x, StringPiece y);
+bool operator>=(StringPiece x, StringPiece y);
+
+bool HasPrefix(StringPiece s, StringPiece prefix);
+bool HasSuffix(StringPiece s, StringPiece suffix);
+
+StringPiece SkipPrefix(StringPiece s, size_t n);
+StringPiece SkipSuffix(StringPiece s, size_t n);
+
+// Skip the prefix (or suffix) if it matches with the string.
+StringPiece TrimPrefix(StringPiece s, StringPiece prefix);
+StringPiece TrimSuffix(StringPiece s, StringPiece suffix);
+
+// Returns if s contains sub.  Any s except for empty s contains an
+// empty sub.
+bool Contains(StringPiece s, StringPiece sub);
+
+// Return the first occurrence of sub in s, or npos.  If both s and
+// sub is empty, it returns npos; otherwise, if only sub is empty, it
+// returns 0.
+size_t Index(StringPiece s, StringPiece sub);
+
+// Return the first occurrence of c in s[pos:end], or npos.
+size_t Find(StringPiece s, char c, size_t pos);
+
+// Search range is [0..pos] inclusive.  If pos == npos, search everything.
+size_t RFind(StringPiece s, char c, size_t pos);
+
+StringPiece SubStr(StringPiece s, size_t pos, size_t n);
+
+// allow StringPiece to be logged
+std::ostream& operator<<(std::ostream& o, StringPiece piece);
+
+}  // namespace paddle
diff --git a/paddle/strings/stringpiece_test.cc b/paddle/strings/stringpiece_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2ba66a04f641c3457efa713383484491a213668f
--- /dev/null
+++ b/paddle/strings/stringpiece_test.cc
@@ -0,0 +1,293 @@
+/*
+  Copyright (c) 2016 PaddlePaddle 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 "paddle/strings/stringpiece.h"
+
+#include <sstream>
+
+#include "gtest/gtest.h"
+
+TEST(StringPiece, Construct) {
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ(NULL, s.data());
+    EXPECT_EQ(0U, s.len());
+  }
+  { EXPECT_THROW(paddle::StringPiece s(NULL, 10000U), std::invalid_argument); }
+  {
+    paddle::StringPiece s(NULL);
+    EXPECT_EQ(0U, s.len());
+  }
+  {
+    std::string a;
+    EXPECT_EQ(0U, a.size());
+    paddle::StringPiece s(a);
+    EXPECT_EQ(0U, s.len());
+  }
+}
+
+TEST(StringPiece, CopyAndAssign) {
+  paddle::StringPiece empty;
+  EXPECT_EQ(0U, empty.len());
+
+  paddle::StringPiece a("hello");
+  paddle::StringPiece b = a;
+  EXPECT_EQ(b.len(), strlen("hello"));
+  EXPECT_EQ(a, b);
+
+  std::string storage("hello");
+  paddle::StringPiece c(storage);
+  EXPECT_EQ(a, c);
+  EXPECT_NE(a.data(), c.data());
+}
+
+TEST(StringPiece, Compare) {
+  {
+    paddle::StringPiece a("hello");
+    paddle::StringPiece b("world");
+    EXPECT_TRUE(a != b);
+    EXPECT_FALSE(a == b);
+    EXPECT_TRUE(a < b);
+    EXPECT_TRUE(a <= b);
+    EXPECT_FALSE(a > b);
+    EXPECT_FALSE(a >= b);
+    EXPECT_LT(Compare(a, b), 0);
+    EXPECT_GT(Compare(b, a), 0);
+  }
+  {
+    paddle::StringPiece a, b;
+    EXPECT_TRUE(a == b);
+    EXPECT_FALSE(a != b);
+    EXPECT_FALSE(a < b);
+    EXPECT_FALSE(a > b);
+    EXPECT_TRUE(a <= b);
+    EXPECT_TRUE(a >= b);
+    EXPECT_EQ(0, Compare(a, b));
+    EXPECT_EQ(0, Compare(b, a));
+  }
+}
+
+TEST(StringPiece, ToString) {
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ(std::string(""), s.ToString());
+  }
+  {
+    paddle::StringPiece s(NULL);
+    EXPECT_EQ(std::string(""), s.ToString());
+  }
+  {
+    paddle::StringPiece s("hello");
+    EXPECT_EQ(std::string("hello"), s.ToString());
+  }
+}
+
+TEST(StringPiece, HasPrefixSuffix) {
+  using paddle::HasPrefix;
+  using paddle::HasSuffix;
+  {
+    paddle::StringPiece s;
+    EXPECT_FALSE(HasPrefix(s, "something"));
+    EXPECT_TRUE(HasPrefix(s, ""));
+    EXPECT_FALSE(HasSuffix(s, "something"));
+    EXPECT_TRUE(HasSuffix(s, ""));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_TRUE(HasPrefix(s, ""));
+    EXPECT_TRUE(HasPrefix(s, "a"));
+    EXPECT_TRUE(HasPrefix(s, "ap"));
+    EXPECT_TRUE(HasPrefix(s, "app"));
+
+    EXPECT_TRUE(HasSuffix(s, ""));
+    EXPECT_TRUE(HasSuffix(s, "p"));
+    EXPECT_TRUE(HasSuffix(s, "pp"));
+    EXPECT_TRUE(HasSuffix(s, "app"));
+  }
+}
+
+TEST(StringPiece, SkipPrefixSuffix) {
+  using paddle::SkipPrefix;
+  using paddle::SkipSuffix;
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ("", SkipPrefix(s, 0));
+    EXPECT_THROW(SkipPrefix(s, 1), std::invalid_argument);
+
+    EXPECT_EQ("", SkipSuffix(s, 0));
+    EXPECT_THROW(SkipSuffix(s, 1), std::invalid_argument);
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_EQ("app", SkipPrefix(s, 0));
+    EXPECT_EQ("pp", SkipPrefix(s, 1));
+    EXPECT_EQ("p", SkipPrefix(s, 2));
+    EXPECT_EQ("", SkipPrefix(s, 3));
+    EXPECT_THROW(SkipPrefix(s, 4), std::invalid_argument);
+
+    EXPECT_EQ("app", SkipSuffix(s, 0));
+    EXPECT_EQ("ap", SkipSuffix(s, 1));
+    EXPECT_EQ("a", SkipSuffix(s, 2));
+    EXPECT_EQ("", SkipSuffix(s, 3));
+    EXPECT_THROW(SkipSuffix(s, 4), std::invalid_argument);
+  }
+}
+
+TEST(StringPiece, TrimPrefixSuffix) {
+  using paddle::TrimPrefix;
+  using paddle::TrimSuffix;
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ("", TrimPrefix(s, ""));
+    EXPECT_EQ("", TrimPrefix(s, "something"));
+
+    EXPECT_EQ("", TrimSuffix(s, ""));
+    EXPECT_EQ("", TrimSuffix(s, "something"));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_EQ("app", TrimPrefix(s, ""));
+    EXPECT_EQ("pp", TrimPrefix(s, "a"));
+    EXPECT_EQ("p", TrimPrefix(s, "ap"));
+    EXPECT_EQ("", TrimPrefix(s, "app"));
+    EXPECT_EQ("app", TrimPrefix(s, "something"));
+
+    EXPECT_EQ("app", TrimSuffix(s, ""));
+    EXPECT_EQ("ap", TrimSuffix(s, "p"));
+    EXPECT_EQ("a", TrimSuffix(s, "pp"));
+    EXPECT_EQ("", TrimSuffix(s, "app"));
+    EXPECT_EQ("app", TrimSuffix(s, "something"));
+  }
+}
+
+TEST(StringPiece, Contains) {
+  using paddle::Contains;
+  {
+    paddle::StringPiece s;
+    EXPECT_FALSE(Contains(s, ""));
+    EXPECT_FALSE(Contains(s, "something"));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_TRUE(Contains(s, ""));
+    EXPECT_TRUE(Contains(s, "a"));
+    EXPECT_TRUE(Contains(s, "p"));
+    EXPECT_TRUE(Contains(s, "ap"));
+    EXPECT_TRUE(Contains(s, "pp"));
+    EXPECT_TRUE(Contains(s, "app"));
+    EXPECT_FALSE(Contains(s, "something"));
+  }
+}
+
+TEST(StringPiece, Index) {
+  using paddle::Index;
+  auto npos = paddle::StringPiece::npos;
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ(npos, Index(s, ""));
+    EXPECT_EQ(npos, Index(s, "something"));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_EQ(0U, Index(s, ""));
+    EXPECT_EQ(0U, Index(s, "a"));
+    EXPECT_EQ(1U, Index(s, "p"));
+    EXPECT_EQ(0U, Index(s, "ap"));
+    EXPECT_EQ(1U, Index(s, "pp"));
+    EXPECT_EQ(0U, Index(s, "app"));
+    EXPECT_EQ(npos, Index(s, "something"));
+  }
+}
+
+TEST(StringPiece, Find) {
+  using paddle::Find;
+  auto npos = paddle::StringPiece::npos;
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ(npos, Find(s, 'a', 0U));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_EQ(0U, Find(s, 'a', 0U));
+    EXPECT_EQ(1U, Find(s, 'p', 0U));
+    EXPECT_EQ(1U, Find(s, 'p', 1U));
+    EXPECT_EQ(2U, Find(s, 'p', 2U));
+    EXPECT_EQ(npos, Find(s, 'z', 2U));
+  }
+}
+
+TEST(StringPiece, RFind) {
+  using paddle::RFind;
+  auto npos = paddle::StringPiece::npos;
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ(npos, RFind(s, 'a', 0U));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_EQ(2U, RFind(s, 'p', 2U));
+    EXPECT_EQ(0U, RFind(s, 'a', 2U));
+    EXPECT_EQ(1U, RFind(s, 'p', 1U));
+    EXPECT_EQ(0U, RFind(s, 'a', 0));
+    EXPECT_EQ(npos, RFind(s, 'z', 2U));
+  }
+}
+
+TEST(StringPiece, SubStr) {
+  using paddle::SubStr;
+  {
+    paddle::StringPiece s;
+    EXPECT_EQ("", SubStr(s, 0, 0));
+    EXPECT_EQ("", SubStr(s, 0, 1));
+    EXPECT_EQ("", SubStr(s, 1, 0));
+  }
+  {
+    paddle::StringPiece s("app");
+    EXPECT_EQ("", SubStr(s, 0, 0));
+    EXPECT_EQ("", SubStr(s, 1, 0));
+    EXPECT_EQ("", SubStr(s, 2, 0));
+    EXPECT_EQ("", SubStr(s, 3, 0));
+
+    EXPECT_EQ("a", SubStr(s, 0, 1));
+    EXPECT_EQ("p", SubStr(s, 1, 1));
+    EXPECT_EQ("p", SubStr(s, 2, 1));
+    EXPECT_EQ("", SubStr(s, 3, 1));
+
+    EXPECT_EQ("ap", SubStr(s, 0, 2));
+    EXPECT_EQ("pp", SubStr(s, 1, 2));
+    EXPECT_EQ("p", SubStr(s, 2, 2));
+    EXPECT_EQ("", SubStr(s, 3, 2));
+
+    EXPECT_EQ("app", SubStr(s, 0, 3));
+    EXPECT_EQ("pp", SubStr(s, 1, 3));
+    EXPECT_EQ("p", SubStr(s, 2, 3));
+    EXPECT_EQ("", SubStr(s, 3, 3));
+  }
+}
+
+TEST(StringPiece, StreamOutput) {
+  using paddle::StringPiece;
+
+  std::stringstream o;
+  o << StringPiece();
+  EXPECT_EQ("", o.str());
+
+  o << StringPiece("hello");
+  EXPECT_EQ("hello", o.str());
+
+  o << StringPiece();
+  EXPECT_EQ("hello", o.str());
+}
diff --git a/python/paddle/trainer/config_parser.py b/python/paddle/trainer/config_parser.py
index dd72be8fd510c813d134a53d54ef226e709fca92..0792e2d40b43f5fb2de8d6bb43a62cfa23f77082 100644
--- a/python/paddle/trainer/config_parser.py
+++ b/python/paddle/trainer/config_parser.py
@@ -3563,11 +3563,7 @@ def update_g_config():
     return g_config
 
 
-def begin_parse(config_arg_str=''):
-    '''
-    @param config_arg_str: a string of the form var1=val1,var2=val2. It will be
-    passed to config script as a dictionary CONFIG_ARGS
-    '''
+def begin_parse():
     init_config_environment()
     for hook in _parse_config_hooks:
         hook()
@@ -3585,8 +3581,12 @@ def begin_parse(config_arg_str=''):
 
 
 def parse_config(trainer_config, config_arg_str):
-    begin_parse(config_arg_str)
+    '''
+    @param config_arg_str: a string of the form var1=val1,var2=val2. It will be
+    passed to config script as a dictionary CONFIG_ARGS
+    '''
 
+    begin_parse()
     config_args = {}
 
     if config_arg_str:
diff --git a/python/paddle/trainer_config_helpers/layers.py b/python/paddle/trainer_config_helpers/layers.py
index 1c3d776a4f36870ba1fb1128da863dffc29debd9..2d8ddbb9007b241eb1986887d8ea6c2de8235c29 100755
--- a/python/paddle/trainer_config_helpers/layers.py
+++ b/python/paddle/trainer_config_helpers/layers.py
@@ -122,6 +122,7 @@ __all__ = [
     'layer_support',
     'multiplex_layer',
     'row_conv_layer',
+    'dropout_layer',
     'prelu_layer',
 ]
 
@@ -3773,7 +3774,6 @@ def beam_search(step,
     assert generated_input_index != -1
 
     gipt = input[generated_input_index]
-    assert isinstance(gipt, BaseGeneratedInput)
 
     gipt.bos_id = bos_id
     gipt.eos_id = eos_id
@@ -3793,7 +3793,6 @@ def beam_search(step,
         predict = gipt.after_real_step(step(*args))
 
         eos_layer(input=predict, eos_id=eos_id, name=eos_name)
-
         return predict
 
     tmp = recurrent_group(
@@ -5569,6 +5568,24 @@ def multiplex_layer(input, name=None, layer_attr=None):
         size=l.config.size)
 
 
+@wrap_name_default("dropout")
+def dropout_layer(input, dropout_rate, name=None):
+    """
+    @TODO(yuyang18): Add comments.
+
+    :param name:
+    :param input:
+    :param dropout_rate:
+    :return:
+    """
+    return addto_layer(
+        name=name,
+        input=input,
+        act=LinearActivation(),
+        bias_attr=False,
+        layer_attr=ExtraAttr(drop_rate=dropout_rate))
+
+
 @wrap_name_default()
 @wrap_act_default(act=LinearActivation())
 @wrap_param_attr_default()
diff --git a/python/paddle/trainer_config_helpers/networks.py b/python/paddle/trainer_config_helpers/networks.py
index fb533a47e0b0585be6f0e019086993f8b3aa7f38..1bf59ed4840ae69afc5bce49c86a08b60e9603ee 100755
--- a/python/paddle/trainer_config_helpers/networks.py
+++ b/python/paddle/trainer_config_helpers/networks.py
@@ -26,10 +26,10 @@ from paddle.trainer.config_parser import *
 
 __all__ = [
     'sequence_conv_pool', 'simple_lstm', "simple_img_conv_pool",
-    "img_conv_bn_pool", 'dropout_layer', 'lstmemory_group', 'lstmemory_unit',
-    'small_vgg', 'img_conv_group', 'vgg_16_network', 'gru_unit', 'gru_group',
-    'simple_gru', 'simple_attention', 'simple_gru2', 'bidirectional_gru',
-    'text_conv_pool', 'bidirectional_lstm', 'inputs', 'outputs'
+    "img_conv_bn_pool", 'lstmemory_group', 'lstmemory_unit', 'small_vgg',
+    'img_conv_group', 'vgg_16_network', 'gru_unit', 'gru_group', 'simple_gru',
+    'simple_attention', 'simple_gru2', 'bidirectional_gru', 'text_conv_pool',
+    'bidirectional_lstm', 'inputs', 'outputs'
 ]
 
 ######################################################
@@ -1366,29 +1366,6 @@ def simple_attention(encoded_sequence,
         input=scaled, pooling_type=SumPooling(), name="%s_pooling" % name)
 
 
-############################################################################
-#                         Miscs                                            #
-############################################################################
-
-
-@wrap_name_default("dropout")
-def dropout_layer(input, dropout_rate, name=None):
-    """
-    @TODO(yuyang18): Add comments.
-
-    :param name:
-    :param input:
-    :param dropout_rate:
-    :return:
-    """
-    return addto_layer(
-        name=name,
-        input=input,
-        act=LinearActivation(),
-        bias_attr=False,
-        layer_attr=ExtraAttr(drop_rate=dropout_rate))
-
-
 def inputs(layers, *args):
     """
     Declare the inputs of network. The order of input should be as same as
diff --git a/python/paddle/v2/layer.py b/python/paddle/v2/layer.py
index 815635f5dd4654fe3a31a9244e6e4473c397dd2f..aeed9ebd7d4d64efa5d0bf1638742a485c0fa44a 100644
--- a/python/paddle/v2/layer.py
+++ b/python/paddle/v2/layer.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 """
 `paddle.v2.layer` is a part of model config packages in paddle.v2. In API v2,
-we want to make Paddle a plain Python package. The model config package defined
+we want to make Paddle a plain Python package. The model config package defines
 the way how to configure a neural network topology in Paddle Python code.
 
 The primary usage shows below.
@@ -30,7 +30,6 @@ The primary usage shows below.
     # use prediction instance where needed.
     parameters = paddle.parameters.create(cost)
 """
-
 import collections
 import copy
 import re
@@ -44,9 +43,10 @@ __all__ = ['data', 'parse_network']
 
 
 def __need_to_keep__(name):
-    if name in ['StaticInput', 'LayerType', 'layer_support']:
-        return False
-    return True
+    return name in [
+        'StaticInput', 'SubsequenceInput', 'GeneratedInput', 'LayerType',
+        'layer_support'
+    ]
 
 
 def __need_to_wrap__(name):
@@ -54,6 +54,8 @@ def __need_to_wrap__(name):
 
 
 def __convert_name__(inname):
+    if __need_to_keep__(inname):
+        return inname
     if inname == 'maxid_layer':
         return 'max_id'
     elif inname.endswith('memory') or inname.endswith(
@@ -74,8 +76,6 @@ def __convert_name__(inname):
 
 for name in v1_layers.__all__:
     obj = getattr(v1_layers, name)
-    if not __need_to_keep__(name):
-        continue
     new_name = __convert_name__(name)
     if callable(obj) and __need_to_wrap__(name):
         globals()[new_name] = __convert_to_v2__(obj, new_name, __name__)
@@ -107,7 +107,7 @@ __data_layer__.__doc__ = __map_data_docstr__(v1_layers.data_layer.__doc__)
 data = __convert_to_v2__(__data_layer__, 'name', __name__)
 
 
-def __get_used_layers__(output_layers, extra_layers=None):
+def __get_used_layers__(output_layers):
     layer_names = set()
     parents = {}
 
@@ -132,6 +132,13 @@ def __get_used_layers__(output_layers, extra_layers=None):
                     add_parent(mem.layer_name, mem.boot_layer_name)
                 add_parent(mem.link_name, mem.layer_name)
 
+            if sub_model.HasField('generator'):
+                # according to the implementation of text generation
+                # in recurrent layer group, the generated word must be
+                # the first out link
+                add_parent(sub_model.out_links[0].layer_name,
+                           sub_model.generator.eos_layer_name)
+
     def dfs_travel(layer_name):
         if layer_name in layer_names:
             return
@@ -247,9 +254,9 @@ def __trim_submodel__(old_submodel, layer_names, input_layer_names,
 def parse_network(output_layers, extra_layers=None):
     if not isinstance(output_layers, collections.Sequence):
         output_layers = [output_layers]
-    if extra_layers is not None and not isinstance(extra_layers,
-                                                   collections.Sequence):
-        extra_layers = [extra_layers]
+    if extra_layers is not None:
+        if not isinstance(extra_layers, collections.Sequence):
+            extra_layers = [extra_layers]
     else:
         extra_layers = []
 
@@ -262,18 +269,29 @@ def parse_network(output_layers, extra_layers=None):
 
     model_config = ModelConfig()
     model_config.type = cp.g_config.model_config.type
+
+    for layer in output_layers:
+        model_config.output_layer_names.append(layer.full_name)
+        output_layer_names.add(layer.full_name)
+
     for l in cp.g_config.model_config.layers:
         if l.name not in layer_names:
             continue
         model_config.layers.extend([l])
         if l.type == 'data':
+            if l.name in model_config.output_layer_names:
+                """
+                In text generation, the outlink to save the generated word
+                indices is a data_layer defined in recurrent_group. This
+                data_layer is sure to be the output of the network in text
+                generation task, so this statement excludes such a special
+                data_layer from being inputs of the network, otherwise an error
+                will occur during data feeding.
+                """
+                continue
             model_config.input_layer_names.append(l.name)
             input_layer_names.add(l.name)
 
-    for layer in output_layers:
-        model_config.output_layer_names.append(layer.full_name)
-        output_layer_names.add(layer.full_name)
-
     for e in cp.g_config.model_config.evaluators:
         if e.name in evaluator_names:
             model_config.evaluators.extend([e])
diff --git a/python/paddle/v2/topology.py b/python/paddle/v2/topology.py
index f3bb4d5f10dd6c5b220161e32dfc3a94642ac7a2..a20e878d0817d0a75e9c47a44f8765deca99225c 100644
--- a/python/paddle/v2/topology.py
+++ b/python/paddle/v2/topology.py
@@ -31,7 +31,6 @@ class Topology(object):
     def __init__(self, layers, extra_layers=None):
         def __check__(layers):
             if not isinstance(layers, collections.Sequence):
-                __check_layer_type__(layers)
                 layers = [layers]
             for layer in layers:
                 __check_layer_type__(layer)
@@ -91,6 +90,7 @@ class Topology(object):
         [('image', dense_vector(768)), ('label', integer_value(10))]
         """
         data_layers = self.data_layers()
+
         return [(nm, data_layers[nm].data_type)
                 for nm in self.proto().input_layer_names]