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layout: default
navsection: installguide
title: Test SLURM dispatch
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{% comment %}
Copyright (C) The Arvados Authors. All rights reserved.

SPDX-License-Identifier: CC-BY-SA-3.0
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{% include 'notebox_begin_warning' %}
crunch-dispatch-slurm is only relevant for on premise clusters that will spool jobs to Slurm. Skip this section if you are installing a cloud cluster.
{% include 'notebox_end' %}

h2. Test compute node setup

You should now be able to submit SLURM jobs that run in Docker containers.  On the node where you're running the dispatcher, you can test this by running:

<notextile>
<pre><code>~$ <span class="userinput">sudo -u <b>crunch</b> srun -N1 docker run busybox echo OK
</code></pre>
</notextile>

If it works, this command should print @OK@ (it may also show some status messages from SLURM and/or Docker).  If it does not print @OK@, double-check your compute node setup, and that the @crunch@ user can submit SLURM jobs.

h2. Test the dispatcher

On the dispatch node, start monitoring the crunch-dispatch-slurm logs:

<notextile>
<pre><code>~$ <span class="userinput">sudo journalctl -o cat -fu crunch-dispatch-slurm.service</span>
</code></pre>
</notextile>

Submit a simple container request:

<notextile>
<pre><code>shell:~$ <span class="userinput">arv container_request create --container-request '{
  "name":            "test",
  "state":           "Committed",
  "priority":        1,
  "container_image": "arvados/jobs:latest",
  "command":         ["echo", "Hello, Crunch!"],
  "output_path":     "/out",
  "mounts": {
    "/out": {
      "kind":        "tmp",
      "capacity":    1000
    }
  },
  "runtime_constraints": {
    "vcpus": 1,
    "ram": 8388608
  }
}'</span>
</code></pre>
</notextile>

This command should return a record with a @container_uuid@ field.  Once @crunch-dispatch-slurm@ polls the API server for new containers to run, you should see it dispatch that same container.  It will log messages like:

<notextile>
<pre><code>2016/08/05 13:52:54 Monitoring container zzzzz-dz642-hdp2vpu9nq14tx0 started
2016/08/05 13:53:04 About to submit queued container zzzzz-dz642-hdp2vpu9nq14tx0
2016/08/05 13:53:04 sbatch succeeded: Submitted batch job 8102
</code></pre>
</notextile>

Before the container finishes, SLURM's @squeue@ command will show the new job in the list of queued and running jobs.  For example, you might see:

<notextile>
<pre><code>~$ <span class="userinput">squeue --long</span>
Fri Aug  5 13:57:50 2016
  JOBID PARTITION     NAME     USER    STATE       TIME TIMELIMIT  NODES NODELIST(REASON)
   8103   compute zzzzz-dz   crunch  RUNNING       1:56 UNLIMITED      1 compute0
</code></pre>
</notextile>

The job's name corresponds to the container's UUID.  You can get more information about it by running, e.g., <notextile><code>scontrol show job Name=<b>UUID</b></code></notextile>.

When the container finishes, the dispatcher will log that, with the final result:

<notextile>
<pre><code>2016/08/05 13:53:14 Container zzzzz-dz642-hdp2vpu9nq14tx0 now in state "Complete" with locked_by_uuid ""
2016/08/05 13:53:14 Monitoring container zzzzz-dz642-hdp2vpu9nq14tx0 finished
</code></pre>
</notextile>

After the container finishes, you can get the container record by UUID *from a shell server* to see its results:

<notextile>
<pre><code>shell:~$ <span class="userinput">arv get <b>zzzzz-dz642-hdp2vpu9nq14tx0</b></span>
{
 ...
 "exit_code":0,
 "log":"a01df2f7e5bc1c2ad59c60a837e90dc6+166",
 "output":"d41d8cd98f00b204e9800998ecf8427e+0",
 "state":"Complete",
 ...
}
</code></pre>
</notextile>

You can use standard Keep tools to view the container's output and logs from their corresponding fields.  For example, to see the logs from the collection referenced in the @log@ field:

<notextile>
<pre><code>~$ <span class="userinput">arv keep ls <b>a01df2f7e5bc1c2ad59c60a837e90dc6+166</b></span>
./crunch-run.txt
./stderr.txt
./stdout.txt
~$ <span class="userinput">arv-get <b>a01df2f7e5bc1c2ad59c60a837e90dc6+166</b>/stdout.txt</span>
2016-08-05T13:53:06.201011Z Hello, Crunch!
</code></pre>
</notextile>

If the container does not dispatch successfully, refer to the @crunch-dispatch-slurm@ logs for information about why it failed.