Windows - IntelMPI 2021.8 unable to stop 4 processes by killing mpiexec

[DanSilva]

Hi,

I came across a potential issue with launching 4 processes for notepad using IntelMPI 2021.8. 

I can launch the processes using Windows PowerShell and navigating to the folder where IntelMPI 2021.8 (and mpiexec.exe) is installed and run the following command form Windows PowerShell:

• .\mpiexec.exe -np 4 "C:\Windows\System32\notepad.exe"

It launches 4 notepad processes and mpiexec.exe (from which I can see in task manager). However when I kill mpiexec.exe in task manager I would expect the 4 notepad processes to die as well but they do not. They hang.

In tried with IntelMPI 2018.3.210. When I run the same command as above using IntelMPI 2018.3.210 I get 4 notepad processes and when I kill mpiexec.exe it automatically kills the 4 processes as well.

So I was wondering about this difference in behaviour between MPI versions. By killing mpiexec.exe should it not kill all attached processes (as seen in version 2018.3.210)?

Thanks in advance.

[AishwaryaCV_Intel · Accepted solution]

Hi,

Thank you for posting in Intel Community.

Please set the following environment variable.

I_MPI_HYDRA_BSTRAP_KEEP_ALIVE

Set this variable to keep hydra_bstrap_proxy alive after launching hydra_pmi_proxy.

Syntax

I_MPI_HYDRA_BSTRAP_KEEP_ALIVE=<arg>

Argument

<arg>	Binary indicator
enable | yes | on | 1	Do not close hydra_bstrap_proxy.
disable | no | off | 0	Close hydra_bstrap_proxy. This is the default value.

Description

Set this variable to keep hydra_bstrap_proxy alive after launching hydra_pmi_proxy. It allows you to keep full process tree (mpiexec —> hydra_bstrap_proxy —> hydra_pmi_proxy —> app) connected on localhost. The default value closes hydra_bstrap_proxy to reduce the number of running processes.

Please refer this link 

Thanks and regards,

Aishwarya

[DanSilva]

Thanks Aishwarya for the information.

I have set the environment variable to I_MPI_HYDRA_BSTRAP_KEEP_ALIVE = yes. I can clearly see all my processes (mpiexec —> hydra_bstrap_proxy —> hydra_pmi_proxy —> app) in task manager. However, I would expect that killing mpiexec.exe should kill all the remain processes including the app (notepad.exe in here).  Is this not the case? If I kill mpiexec.exe all the remain processes stay alive (I would expect them to die as well). I observe this in 2021.8.

In version 2018.3.210 if I kill mpiexec.exe, notepad.exe dies as well.

Thanks again,

Dan

[DanSilva]

Just wanted to say that this has solved my problem in my original application.

Thanks once again

Dan

[AishwaryaCV_Intel]

Hi,

Thanks for accepting our solution. If you need any additional information, please post a new question as this thread will no longer be monitored by Intel.

Thanks and regards,

Aishwarya