# Use KNIME to run remote jobs

**URL:** <https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836>\
**Category:** BioInformatics\
**Created:** [August 16, 2018, 3:24pm UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836 "2018-08-16T15:24:43Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![gugy](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/g/dec6dc/32.png) [@gugy](https://forum.knime.com/u/gugy)\
**Post date:** [August 16, 2018, 3:24pm UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/1 "2018-08-16T15:24:43Z")

</div>

I am a complete newbie to KNIME, but would like to use it for a very specific task:  
I want to use a KNIME workflow to submit Molecular Dynamics simulations to a supercomputer. The simulations will be run with GROMACS, and submitted via simple bash/unix scripts, GROMACS is running on the supercomputer itself.

Any pointers to how to do this are very much appreciated - I have no clue where to start.

Cheers  
Gudrun

---

<div class="post-metadata">

**Author:** ![Iris](https://forum-cdn.knime.com/user_avatar/forum.knime.com/iris/32/14_2.png) [@Iris](https://forum.knime.com/u/Iris)\
**Post date:** [August 20, 2018, 6:55am UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/2 "2018-08-20T06:55:34Z")

</div>

Hi Gugy,

you should be able to do this with the external tools node.

> **[External Tool — NodePit](https://nodepit.com/node/org.knime.ext.exttool.ExtToolNodeFactory)**
>
> Executes an external tool.

Cheers, Iris

---

<div class="post-metadata">

**Author:** ![gugy](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/g/dec6dc/32.png) [@gugy](https://forum.knime.com/u/gugy)\
**Post date:** [August 24, 2018, 1:26pm UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/3 "2018-08-24T13:26:20Z")

</div>

Hi Iris,  
thanks for the reply. I am having trouble understanding how the different external tool nodes work…

From what I understand, the External ssh tool is suitable for me: I want to execute scripts on a remote server (I can do that with ‘remote command’). What I do not understand is what the temporary in and out files are supposed to do, they get deleted after executing the node, but have to be present before executing it???

To debug, I am manually creating empty files so that the node runs… Surely, this is not how it is supposed to work, and I am totally clueless.

My remote command to test is just:  
ls -ltr \> test  
In the end, I would like to either do sth like this (file read, file saved):  
grep ‘ALA’ protein.pdb \>out.txt  
or  
./script  
with script containing the lines  
#!/bin/bash  
grep ‘ALA’ protein.pdb \>out.txt

I cannot find a MWE with an external ssh node, maybe you can provide one?

Cheers  
Gudrun

---

<div class="post-metadata">

**Author:** ![gab1one](https://forum-cdn.knime.com/user_avatar/forum.knime.com/gab1one/32/461_2.png) [@gab1one](https://forum.knime.com/u/gab1one)\
**Post date:** [September 3, 2018, 2:14pm UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/4 "2018-09-03T14:14:07Z")

</div>

Hi @gugy,  
Please excuse the late response, I just discovered this post.  
You do not need to create the temporary input file, but you need to fill the output file with some content. The easiest way to ensure this is done correctly is to use the `$outFile` variable in your command and specifying full paths to input and output files. If you do not need the input table at all, you can connect for example an **Empty Table Creator** node and set the input file to `/dev/null`:

 ![Selection_020](https://forum-cdn.knime.com/uploads/default/original/2X/9/9fa7cd8e980999ffad1e48dc46c91b4aeb2a2483.png)

best,  
Gabriel

---

<div class="post-metadata">

**Author:** ![RTommasi](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/r/6de8d8/32.png) [@RTommasi](https://forum.knime.com/u/RTommasi)\
**Post date:** [July 1, 2021, 4:52pm UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/5 "2021-07-01T16:52:40Z")

</div>

Hi,  
I realize this is an older post, but there’s still some logic i don’t understand here. If you can pass a null variable to the input, why can’t that also be done for the output? I am trying to use External SSH to start a script that takes care of the output in a different manner. Whenever there is a failed run, the blank output file i am using gets erased. Is there a way to circumvent this?  
thanks  
Ruben

---

<div class="post-metadata">

**Author:** ![gab1one](https://forum-cdn.knime.com/user_avatar/forum.knime.com/gab1one/32/461_2.png) [@gab1one](https://forum.knime.com/u/gab1one)\
**Post date:** [July 2, 2021, 8:07am UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/6 "2021-07-02T08:07:35Z")

</div>

Hi @RTommasi,

just a quick idea, how about running a command like  
`touch /tmp/fakeoutput && your_command ` and set `/tmp/faekoutput` as your remote output file?

best,  
Gabriel

---

<div class="post-metadata">

**Author:** ![system](https://forum-cdn.knime.com/uploads/default/original/1X/ab3ccf34482a0329361734a18199390177204f15.png) [@system](https://forum.knime.com/u/system)\
**Post date:** [June 23, 2023, 8:30pm UTC](https://forum.knime.com/t/use-knime-to-run-remote-jobs/11836/7 "2023-06-23T20:30:33Z")

</div>


