Tensorflow is a commonly used Python package for deep learning.

Basic usage

First, check the tutorials up to and including GPU computing.

With tensorflow, you have to decide at install time if you want a version that runs on CPUs or GPUs. This means that we can’t install it for everyone and expect it to work everywhere - you have to load something different if you want it to run on login node/regular nodes (probably for testing) or GPU nodes. You probably want to use GPUs.

The basic way to use is via the Python in the anaconda3 module (or anaconda2) - but these modules have the GPU version installed, so you can’t run or test on the login node.

If you module spider anaconda3 (or 2), you can see several versions ending in -cpu or -gpu. These have respectively the CPU and GPU versions of tensorflow installed.

If you use GPUs, you need --constraint='kepler|pascal|volta' in order to select a GPU new enough to run tensorflow. (Note that as we get never cards, this will need further updating).



[email protected]@login2:~$ module load anaconda3

[email protected]:~$ srun --pty --gres=gpu --constraint='kepler|pascal|volta' bash
srun: job 33637511 queued and waiting for resources
srun: job 33637511 has been allocated resources

[email protected]:~$ python
Python 3.6.6 |Anaconda custom (64-bit)| (default, Jun 28 2018,
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import tensorflow

As a batch script (submit with sbatch):

#!/bin/bash -l
#SBATCH --gres=gpu
#SBATCH --constraint='kepler|pascal|volta'

module load anaconda3
python my_script.py

Example 2 (older)


You no longer need to manually install tensorflow, so the first part of this example is not relevant anymore.

This chapter gives a step-by-step guide how to run the tensorflow cifar10 example on 4 gpu’s. All commands below are typed on the login node, it is not necessary to ssh to a gpu node first.

First load anaconda (python), CUDA and cudnn

$ module load anaconda2 CUDA/7.5.18 cudnn/4

After that create a conda environment to install tensorflow in:

$ conda create -n tensorflow python=2.7

$ source activate tensorflow
$ pip install --ignore-installed --upgrade https://storage.googleapis.com/tensorflow/linux/gpu/tensorflow-0.8.0-cp27-none-linux_x86_64.whl
$ pip install --upgrade https://storage.googleapis.com/tensorflow/linux/gpu/tensorflow-0.8.0-cp27-none-linux_x86_64.whl

For some (unclear) reason you have to run the pip command twice, first with --ignore-installed and second time without to make the conda environment work.

Now we can create a batch script (submit_cifar.sh) that runs this code on 4 gpus


#Request 4 gpus
#SBATCH --gres=gpu:4 --constraint='kepler|pascal|volta'
#SBATCH --mem-per-cpu 10G
#SBATCH -t 4:00:00

module load anaconda2 CUDA/7.5.18 cudnn/4
source activate tensorflow

python -m tensorflow.models.image.cifar10.cifar10_multi_gpu_train --num-gpus 4

You can submit this job with

$ sbatch submit_cifar.sh

and you’ll be able to find the results in the slurm log file.