How to install horovod

refer
refer
cuda 는 알아서 설치 요망
prerequisit: NCCL for Multi-GPU, gcc compllier, anaconda gxx complier, tensorflow-gpu, openmpi

1. install nccl
2. install gcc version 4.9
3. if you use anaconda virtual environment, install anaconda g++ complier
4. install tensorflow-gpu
5. install openmpi
6. install horovod with tensorflow

1. install nccl
   refer
   Download Network Installer for Ubuntu16.04

   $ sudo dpkg -i nvidia-machine-learning-repo-<version>.deb
   $ sudo apt update
   $ sudo apt install libnccl2=2.5.6-1+cuda10.0 libnccl-dev=2.5.6-1+cuda10.0
   

   version = 2.5.6
   version check

2. locate nccl| grep "libnccl.so" | tail -n1 | sed -r 's/^.*\.so\.//'

3. install gcc version 4.9
   GCC, G++ 버전관리
   refer

   sudo update-alternatives --display  gcc
   sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 40 --slave /usr/bin/g++ g++ /usr/bin/g++-7
   sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 20 --slave /usr/bin/g++ g++ /usr/bin/g++-5 
   sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.9 
       
   gcc --version
   

4. if you use anaconda virtual environment, install anaconda g++ complier

   conda install -c anaconda gxx\_linux-64
   

5. install tensorflow-gpu

   conda install -c anaconda tensorflow-gpu=2.0.0
   

6. install openmpi

   conda install -c conda-forge openmpi
   

7. install horovod with tensorflow
   NCCL 헤더와 라이브러리 파일 경로, cuda 경로를 잘 넣어주어야 한다.

     HOROVOD\_NCCL\_INCLUDE=/usr/include HOROVOD\_NCCL\_LIB=/usr/lib/x86\_64-linux-gnu HOROVOD\_CUDA\_HOME=/usr/local/cuda-10.0 HOROVOD\_WITH\_TENSORFLOW=1 pip install --force-reinstall --no-deps --no-cache-dir horovod==0.18.1