MirrorStrategy doesn't see GPU - INFO:tensorflow:Not using Distribute Coordinator

[Nicolabo]

Hi,
Thanks for your clear example. I was trying to replicate your solution to see how MirrorStrategy works.

However once I run the code:

distribution = tf.contrib.distribute.MirroredStrategy()
config = tf.estimator.RunConfig(train_distribute= distribution,
                                model_dir="/tmp/mnist_convnet_model")

I get a warning:

INFO:tensorflow:Initializing RunConfig with distribution strategies.
INFO:tensorflow:Not using Distribute Coordinator.

I turn on GPU on Colab. I also tested it on EC2 instance with several GPUs. Do you know what wrong with this stuff?

Thanks,