openmpi python超过3个进程答案

【问题标题】：openmpi python more than 3 prcocessesopenmpi python超过3个进程
【发布时间】：2017-03-12 21:30:11
【问题描述】：

我运行了一个包含 3 个以上进程的简单 mpi python 程序。例如：

mpiexec -host master,w1,w2,w3 python code.py

显示有一些错误

ssh: Could not resolve hostname w3: Name or service not known
ORTE was unable to reliably start one or more daemons.

This usually is caused by:

* not finding the required libraries and/or binaries on
  one or more nodes. Please check your PATH and LD_LIBRARY_PATH
  settings, or configure OMPI with --enable-orterun-prefix-by-default

* lack of authority to execute on one or more specified nodes.
  Please verify your allocation and authorities.

* the inability to write startup files into /tmp (--tmpdir/orte_tmpdir_base).
  Please check with your sys admin to determine the correct location to use.

*  compilation of the orted with dynamic libraries when static are required
  (e.g., on Cray). Please check your configure cmd line and consider using
  one of the contrib/platform definitions for your system type.

* an inability to create a connection back to mpirun due to a
  lack of common network interfaces and/or no route found between
  them. Please check network connectivity (including firewalls
  and network routing requirements).

但是，如果我使用 w1、w2、w3 中的任意两个运行程序，它就可以工作。例如：

mpiexec -host master,w1,w3 python code.py

而且，这是代码

 import random
 import numpy as np
 from mpi4py import MPI

 comm = MPI.COMM_WORLD
 rank = comm.rank
 size = comm.size

 if rank ==0:
 print rank, 'worker'
 else:
 print rank, 'worker'

我该如何解决？谢谢。

【问题讨论】：

标签： linux networking ssh python

【解决方案1】：

根据输出：ssh: Could not resolve hostname w3: Name or service not known，问题很清楚：

您的主节点（机器）无法识别主机名w3。您可以将name-ip 映射添加到/etc/hosts，格式为ip name。例如： 255.255.255.0 the_name

【讨论】：