Add distributed implementation for recommender system (#7810)

* Add distributed implementation for recommender system

* Addressing code review feedback

python/paddle/v2/fluid/tests/book_distribute/notest_recommender_system_dist.py

+#   Copyright (c) 2018 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.
+
+import numpy as np
+import os
+import paddle.v2 as paddle
+import paddle.v2.fluid as fluid
+import paddle.v2.fluid.core as core
+import paddle.v2.fluid.layers as layers
+import paddle.v2.fluid.nets as nets
+from paddle.v2.fluid.optimizer import SGDOptimizer
+
+IS_SPARSE = True
+BATCH_SIZE = 256
+PASS_NUM = 100
+
+
+def get_usr_combined_features():
+    USR_DICT_SIZE = paddle.dataset.movielens.max_user_id() + 1
+    uid = layers.data(name='user_id', shape=[1], dtype='int64')
+    usr_emb = layers.embedding(
+        input=uid,
+        dtype='float32',
+        size=[USR_DICT_SIZE, 32],
+        param_attr='user_table',
+        is_sparse=IS_SPARSE)
+    usr_fc = layers.fc(input=usr_emb, size=32)
+    USR_GENDER_DICT_SIZE = 2
+
+    usr_gender_id = layers.data(name='gender_id', shape=[1], dtype='int64')
+    usr_gender_emb = layers.embedding(
+        input=usr_gender_id,
+        size=[USR_GENDER_DICT_SIZE, 16],
+        param_attr='gender_table',
+        is_sparse=IS_SPARSE)
+    usr_gender_fc = layers.fc(input=usr_gender_emb, size=16)
+
+    USR_AGE_DICT_SIZE = len(paddle.dataset.movielens.age_table)
+    usr_age_id = layers.data(name='age_id', shape=[1], dtype="int64")
+    usr_age_emb = layers.embedding(
+        input=usr_age_id,
+        size=[USR_AGE_DICT_SIZE, 16],
+        is_sparse=IS_SPARSE,
+        param_attr='age_table')
+    usr_age_fc = layers.fc(input=usr_age_emb, size=16)
+
+    USR_JOB_DICT_SIZE = paddle.dataset.movielens.max_job_id() + 1
+    usr_job_id = layers.data(name='job_id', shape=[1], dtype="int64")
+    usr_job_emb = layers.embedding(
+        input=usr_job_id,
+        size=[USR_JOB_DICT_SIZE, 16],
+        param_attr='job_table',
+        is_sparse=IS_SPARSE)
+    usr_job_fc = layers.fc(input=usr_job_emb, size=16)
+
+    concat_embed = layers.concat(
+        input=[usr_fc, usr_gender_fc, usr_age_fc, usr_job_fc], axis=1)
+
+    usr_combined_features = layers.fc(input=concat_embed, size=200, act="tanh")
+    return usr_combined_features
+
+
+def get_mov_combined_features():
+    MOV_DICT_SIZE = paddle.dataset.movielens.max_movie_id() + 1
+    mov_id = layers.data(name='movie_id', shape=[1], dtype='int64')
+    mov_emb = layers.embedding(
+        input=mov_id,
+        dtype='float32',
+        size=[MOV_DICT_SIZE, 32],
+        param_attr='movie_table',
+        is_sparse=IS_SPARSE)
+    mov_fc = layers.fc(input=mov_emb, size=32)
+
+    CATEGORY_DICT_SIZE = len(paddle.dataset.movielens.movie_categories())
+    category_id = layers.data(name='category_id', shape=[1], dtype='int64')
+    mov_categories_emb = layers.embedding(
+        input=category_id, size=[CATEGORY_DICT_SIZE, 32], is_sparse=IS_SPARSE)
+    mov_categories_hidden = layers.sequence_pool(
+        input=mov_categories_emb, pool_type="sum")
+
+    MOV_TITLE_DICT_SIZE = len(paddle.dataset.movielens.get_movie_title_dict())
+    mov_title_id = layers.data(name='movie_title', shape=[1], dtype='int64')
+    mov_title_emb = layers.embedding(
+        input=mov_title_id, size=[MOV_TITLE_DICT_SIZE, 32], is_sparse=IS_SPARSE)
+    mov_title_conv = nets.sequence_conv_pool(
+        input=mov_title_emb,
+        num_filters=32,
+        filter_size=3,
+        act="tanh",
+        pool_type="sum")
+
+    concat_embed = layers.concat(
+        input=[mov_fc, mov_categories_hidden, mov_title_conv], axis=1)
+
+    mov_combined_features = layers.fc(input=concat_embed, size=200, act="tanh")
+    return mov_combined_features
+
+
+def model():
+    usr_combined_features = get_usr_combined_features()
+    mov_combined_features = get_mov_combined_features()
+
+    # need cos sim
+    inference = layers.cos_sim(X=usr_combined_features, Y=mov_combined_features)
+    scale_infer = layers.scale(x=inference, scale=5.0)
+
+    label = layers.data(name='score', shape=[1], dtype='float32')
+    square_cost = layers.square_error_cost(input=scale_infer, label=label)
+    avg_cost = layers.mean(x=square_cost)
+
+    return avg_cost
+
+
+def func_feed(feeding, data, place):
+    feed_tensors = {}
+    for (key, idx) in feeding.iteritems():
+        tensor = core.LoDTensor()
+        if key != "category_id" and key != "movie_title":
+            if key == "score":
+                numpy_data = np.array(map(lambda x: x[idx], data)).astype(
+                    "float32")
+            else:
+                numpy_data = np.array(map(lambda x: x[idx], data)).astype(
+                    "int64")
+        else:
+            numpy_data = map(lambda x: np.array(x[idx]).astype("int64"), data)
+            lod_info = [len(item) for item in numpy_data]
+            offset = 0
+            lod = [offset]
+            for item in lod_info:
+                offset += item
+                lod.append(offset)
+            numpy_data = np.concatenate(numpy_data, axis=0)
+            tensor.set_lod([lod])
+
+        numpy_data = numpy_data.reshape([numpy_data.shape[0], 1])
+        tensor.set(numpy_data, place)
+        feed_tensors[key] = tensor
+    return feed_tensors
+
+
+def main():
+    cost = model()
+    optimizer = SGDOptimizer(learning_rate=0.2)
+    optimize_ops, params_grads = optimizer.minimize(cost)
+
+    train_reader = paddle.batch(
+        paddle.reader.shuffle(
+            paddle.dataset.movielens.train(), buf_size=8192),
+        batch_size=BATCH_SIZE)
+
+    place = fluid.CPUPlace()
+    exe = fluid.Executor(place)
+
+    t = fluid.DistributeTranspiler()
+
+    # all parameter server endpoints list for spliting parameters
+    pserver_endpoints = os.getenv("PSERVERS")
+    # server endpoint for current node
+    current_endpoint = os.getenv("SERVER_ENDPOINT")
+    # run as trainer or parameter server
+    training_role = os.getenv("TRAINING_ROLE", "TRAINER")
+    t.transpile(
+        optimize_ops, params_grads, pservers=pserver_endpoints, trainers=2)
+
+    if training_role == "PSERVER":
+        if not current_endpoint:
+            print("need env SERVER_ENDPOINT")
+            exit(1)
+        pserver_prog = t.get_pserver_program(current_endpoint)
+        pserver_startup = t.get_startup_program(current_endpoint, pserver_prog)
+        exe.run(pserver_startup)
+        exe.run(pserver_prog)
+    elif training_role == "TRAINER":
+        exe.run(fluid.default_startup_program())
+        trainer_prog = t.get_trainer_program()
+
+        feeding = {
+            'user_id': 0,
+            'gender_id': 1,
+            'age_id': 2,
+            'job_id': 3,
+            'movie_id': 4,
+            'category_id': 5,
+            'movie_title': 6,
+            'score': 7
+        }
+
+        for pass_id in range(PASS_NUM):
+            for data in train_reader():
+                outs = exe.run(trainer_prog,
+                               feed=func_feed(feeding, data, place),
+                               fetch_list=[cost])
+                out = np.array(outs[0])
+                print("cost=" + str(out[0]))
+                if out[0] < 6.0:
+                    print("Training complete. Average cost is less than 6.0.")
+                    # if avg cost less than 6.0, we think our code is good.
+                    exit(0)
+    else:
+        print("environment var TRAINER_ROLE should be TRAINER os PSERVER")
+
+
+if __name__ == '__main__':
+    main()