线程、分布式环境下，恢复Model时的Tensor Graph和生成Model时不同,预测报错

TensorFlow相关学习

https://blog.csdn.net/xierhacker/article/details/53860379

Not An Element Of Tensor Graph

错误:TypeError: Cannot interpret feed_dict key as Tensor: Tensor Tensor(“Placeholder_2:0”, shape=(500, 500), dtype=float32) is not an element of this graph.

Exception in thread Thread-2:                                                   
Traceback (most recent call last):
  File "/home/ubuntu/anaconda2/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/home/ubuntu/anaconda2/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/distkeras/job_deployment.py", line 281, in run
    self.read_trained_model()
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/distkeras/job_deployment.py", line 207, in read_trained_model
    self.trained_model = deserialize_keras_model(unpickle_object(f.read()))
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/distkeras/utils.py", line 127, in deserialize_keras_model
    model.set_weights(weights)
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/keras/models.py", line 700, in set_weights
    self.model.set_weights(weights)
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/keras/engine/topology.py", line 1973, in set_weights
    K.batch_set_value(tuples)
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/keras/backend/tensorflow_backend.py", line 2153, in batch_set_value
    get_session().run(assign_ops, feed_dict=feed_dict)
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 778, in run
    run_metadata_ptr)
  File "/home/ubuntu/anaconda2/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 933, in _run
    + e.args[0])
TypeError: Cannot interpret feed_dict key as Tensor: Tensor Tensor("Placeholder_2:0", shape=(500, 500), dtype=float32) is not an element of this graph.

错误原因：多线程、分布式环境下，恢复Model时的Tensor Graph和生成Model时不同。

解决方法：将生成Model的Tesor Graph复制到恢复线程(或者DataNode)中。

Env:Ubuntu 16.4
spark
keras
Solution:

1.Right after loading or constructing your model, save the TensorFlow graph:

获得默认图

graph = tf.get_default_graph()

2.In the other thread (or perhaps in an asynchronous event handler), do:

global graph

使用图

with graph.as_default():

(... do inference here ...)

I learned about this from https://github.com/fchollet/keras/issues/2397

具体操作如下:

main.py 预加载模型

m keras.models import Sequential

model = Sequential()
model.add(Dense(500, input_shape=(nb_features,)))
model.add(Activation('relu'))
model.add(Dropout(0.4))
model.add(Dense(500))
model.add(Activation('relu'))
model.add(Dense(nb_classes))
model.add(Activation('softmax'))
model.summary()

获得默认图，将预加载的模型 加入graph

from deployment import graph
  graph.append(tf.get_default_graph())

deployment.py

graph = []
class Job(object):
    ...
    def run(self):
        time.sleep(1)
        while not self.is_finished():
            time.sleep(10)
        global graph
## 使用模型
       with graph[0].as_default():        
              (... do inference here ...)

实际应用示例

image.png