Python 关于分布张量流的几个问题

我对分布式张量流有疑问。为了理解它的行为，我在下面的link（）中编写了代码。有两个问题

对于上面的代码，有时我会出错，有时它会工作。当它不工作时，我收到以下错误消息：

回溯（最近一次呼叫最后一次）： 文件“main.py”，第39行，在 _，step=sess.run（[assign\u op，global\u step]） 文件“/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site packages/tensorflow/python/client/session.py”，第767行，正在运行 运行_元数据_ptr） 文件“/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site packages/tensorflow/python/client/session.py”，第965行，正在运行 提要（dict字符串、选项、运行元数据） 文件“/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site packages/tensorflow/python/client/session.py”，第1015行，运行 目标\u列表、选项、运行\u元数据） 文件“/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site packages/tensorflow/python/client/session.py”，第1035行，在 提升类型（e）（节点定义、操作、消息） tensorflow.python.framework.errors\u impl.InvalidArgumentError:/job:worker/replica:0/task:0/gpu:0未知设备。 [[Node:local/add_S3=\u Recv[client_terminated=false，Recv_device=“/job:ps/replica:0/task:0/cpu:0”，send_device=“/job:worker/replica:0/task:0/gpu:0”，send_device_化身=4764918041242746699，tensor_name=“edge_7_local/add”，tensor_type=DT_INT32，_device=“/job:ps/replica:0/task:0/cpu:0”（）] 我不明白为什么会发生这种情况

我使用了两个“工人”作为全局计数器。然而，我发现有些数字是重复的。我怎样才能解决这个问题

Traceback (most recent call last): File "main.py", line 39, in _, step = sess.run([assign_op, global_step]) File "/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 767, in run run_metadata_ptr) File "/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 965, in _run feed_dict_string, options, run_metadata) File "/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 1015, in _do_run target_list, options, run_metadata) File "/home/wsjeon/anaconda2/envs/tensorflow/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 1035, in _do_call raise type(e)(node_def, op, message) tensorflow.python.framework.errors_impl.InvalidArgumentError: /job:worker/replica:0/task:0/gpu:0 unknown device. [[Node: local/add_S3 = _Recv[client_terminated=false, recv_device="/job:ps/replica:0/task:0/cpu:0", send_device="/job:worker/replica:0/task:0/gpu:0", send_device_incarnation=4764918041242746699, tensor_name="edge_7_local/add", tensor_type=DT_INT32, _device="/job:ps/replica:0/task:0/cpu:0"]()]]