Crunch2 installation » History » Revision 11
Revision 10 (Tom Clegg, 06/17/2016 08:26 PM) → Revision 11/18 (Tom Clegg, 06/20/2016 09:29 PM)
h1. Crunch2 installation
(DRAFT -- when ready, this will move to doc.arvados.org→install)
{{toc}}
h2. Set up a crunch-dispatch service
Currently, dispatching containers via SLURM is supported.
Install crunch-dispatch-slurm on a node that can submit SLURM jobs. This can be any node appropriately configured to connect to the SLURM controller node.
<pre><code class="shell">
sudo apt-get install crunch-dispatch-slurm
</code></pre>
Create a privileged Arvados API token for use by the dispatcher. If you have multiple dispatch processes, you should give each one a different token.
<pre><code class="shell">
apiserver:~$ cd /var/www/arvados-api/current
apiserver:/var/www/arvados-api/current$ sudo -u webserver-user RAILS_ENV=production bundle exec script/create_superuser_token.rb
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
</code></pre>
Save the token on the dispatch node, in <code>/etc/sv/crunch-dispatch-slurm/env/ARVADOS_API_TOKEN</code>
Example runit script (@/etc/sv/crunch-dispatch-slurm/run@):
<pre><code class="shell">
#!/bin/sh
set -e
exec 2>&1
export ARVADOS_API_HOST=uuid_prefix.your.domain
exec chpst -e ./env -u crunch crunch-dispatch-slurm
</code></pre>
Example runit logging script (@/etc/sv/crunch-dispatch-slurm/log/run@):
<pre><code class="shell">
#!/bin/sh
set -e
[ -d main ] || mkdir main
exec svlogd -tt ./main
</code></pre>
Ensure the @crunch@ user on the dispatch node can run Docker containers on SLURM compute nodes via @srun@ or @sbatch@. Depending on your SLURM installation, this may require that the @crunch@ user exist -- and have the same UID, GID, and home directory -- on the dispatch node and all SLURM compute nodes.
For example, this should print "OK" (possibly after some extra status/debug messages from SLURM and docker):
<pre>
crunch@dispatch:~$ srun -N1 docker run busybox echo OK
</pre>
h2. Install crunch-run on all compute nodes
<pre><code class="shell">
sudo apt-get install crunch-run
</code></pre>
h2. Enable cgroup accounting on all compute nodes
(This requirement isn't new for crunch2/containers, but it seems to be a FAQ. The Docker install guide mentions it's optional and performance-degrading, so it's not too surprising if people skip it. Perhaps we should say why/when it's a good idea to enable it?)
Check https://docs.docker.com/engine/installation/linux/ for instructions specific to your distribution.
For example, on Ubuntu:
# Update @/etc/default/grub@ to include: <pre>
GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"
</pre>
# @sudo update-grub@
# Reboot
h2. Configure Docker
Unchanged from current docs.
h2. Test the dispatcher
On the dispatch node, monitor the crunch-dispatch logs.
<pre><code class="shell">
dispatch-node$ tail -F /etc/sv/crunch-dispatch-slurm/log/main/current
</code></pre>
(TODO: Add example startup logs from crunch-dispatch-slurm)
On a shell VM, install a Docker image for testing.
<pre><code class="shell">
user@shellvm:~$ arv keep docker busybox
</code></pre>
(TODO: Add example log/debug messages)
On a shell VM, run a trivial container.
<pre><code class="shell">
user@shellvm:~$ arv container_request create --container-request '{
"name": "test",
"state": "Committed",
"priority": 1,
"container_image": "busybox",
"command": ["true"],
"output_path": "/out",
"mounts": {
"/out": {
"kind": "tmp",
"capacity": 1000
}
}
}'
</code></pre>
Measures of success:
* Dispatcher log entries will indicate it has submitted a SLURM job. (TODO: Add example logs.)
* Before the container finishes, SLURM's @squeue@ command will show the new job in the list of queued/running jobs. (TODO: Add squeue output, showing how containers look there.)
* After the container finishes, @arv container list --limit 1@ will indicate the outcome: <pre>
{
...
"exit_code":0,
...
"state":"Complete",
...
}
</pre>