---
layout: default
navsection: userguide
-title: "Parallel Crunch tasks"
+title: "Concurrent Crunch tasks"
...
+{% comment %}
+Copyright (C) The Arvados Authors. All rights reserved.
-In the previous tutorials, we used @arvados.job_setup.one_task_per_input_file()@ to automatically parallelize our jobs by creating a separate task per file. For some types of jobs, you may need to split the work up differently, for example creating tasks to process different segments of a single large file. In this this tutorial will demonstrate how to create Crunch tasks directly.
+SPDX-License-Identifier: CC-BY-SA-3.0
+{% endcomment %}
-Start by entering the @crunch_scripts@ directory of your git repository:
+{% include 'pipeline_deprecation_notice' %}
+
+In the previous tutorials, we used @arvados.job_setup.one_task_per_input_file()@ to automatically create concurrent jobs by creating a separate task per file. For some types of jobs, you may need to split the work up differently, for example creating tasks to process different segments of a single large file. This tutorial will demonstrate how to create Crunch tasks directly.
+
+Start by entering the @crunch_scripts@ directory of your Git repository:
<notextile>
-<pre><code>~$ <span class="userinput">cd <b>you</b>/crunch_scripts</span>
+<pre><code>~$ <span class="userinput">cd $USER/crunch_scripts</span>
</code></pre>
</notextile>
-Next, using @nano@ or your favorite Unix text editor, create a new file called @parallel-hash.py@ in the @crunch_scripts@ directory.
+Next, using @nano@ or your favorite Unix text editor, create a new file called @concurrent-hash.py@ in the @crunch_scripts@ directory.
-notextile. <pre>~/<b>you</b>/crunch_scripts$ <code class="userinput">nano parallel-hash.py</code></pre>
+notextile. <pre>~/$USER/crunch_scripts$ <code class="userinput">nano concurrent-hash.py</code></pre>
-Add the following code to compute the md5 hash of each file in a collection:
+Add the following code to compute the MD5 hash of each file in a collection:
-<notextile> {% code 'parallel_hash_script_py' as python %} </notextile>
+<notextile> {% code 'concurrent_hash_script_py' as python %} </notextile>
Make the file executable:
-notextile. <pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">chmod +x parallel-hash.py</span></code></pre>
+notextile. <pre><code>~/$USER/crunch_scripts$ <span class="userinput">chmod +x concurrent-hash.py</span></code></pre>
-Next, add the file to @git@ staging, commit and push:
+Add the file to the Git staging area, commit, and push:
<notextile>
-<pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">git add parallel-hash.py</span>
-~/<b>you</b>/crunch_scripts$ <span class="userinput">git commit -m"parallel hash"</span>
-~/<b>you</b>/crunch_scripts$ <span class="userinput">git push origin master</span>
+<pre><code>~/$USER/crunch_scripts$ <span class="userinput">git add concurrent-hash.py</span>
+~/$USER/crunch_scripts$ <span class="userinput">git commit -m"concurrent hash"</span>
+~/$USER/crunch_scripts$ <span class="userinput">git push origin master</span>
</code></pre>
</notextile>
-You should now be able to run your new script using Crunch, with "script" referring to our new "parallel-hash.py" script. We will use a different input from our previous examples. We will use @887cd41e9c613463eab2f0d885c6dd96+83@ which consists of three files, "alice.txt", "bob.txt" and "carol.txt" (the example collection used previously in "fetching data from Arvados using Keep":{{site.baseurl}}/user/tutorials/tutorial-keep.html#dir).
+You should now be able to run your new script using Crunch, with "script" referring to our new "concurrent-hash.py" script. We will use a different input from our previous examples. We will use @887cd41e9c613463eab2f0d885c6dd96+83@ which consists of three files, "alice.txt", "bob.txt" and "carol.txt" (the example collection used previously in "fetching data from Arvados using Keep":{{site.baseurl}}/user/tutorials/tutorial-keep.html#dir).
<notextile>
-<pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">cat >~/the_job <<EOF
+<pre><code>~/$USER/crunch_scripts$ <span class="userinput">cat >~/the_job <<EOF
{
- "script": "parallel-hash.py",
- "repository": "$USER",
+ "script": "concurrent-hash.py",
+ "repository": "$USER/$USER",
"script_version": "master",
"script_parameters":
{
}
}
EOF</span>
-~/<b>you</b>/crunch_scripts$ <span class="userinput">arv job create --job "$(cat ~/the_job)"</span>
+~/$USER/crunch_scripts$ <span class="userinput">arv job create --job "$(cat ~/the_job)"</span>
{
...
"uuid":"qr1hi-xxxxx-xxxxxxxxxxxxxxx"
...
}
-~/<b>you</b>/crunch_scripts$ <span class="userinput">arv job get --uuid qr1hi-xxxxx-xxxxxxxxxxxxxxx</span>
+~/$USER/crunch_scripts$ <span class="userinput">arv job get --uuid qr1hi-xxxxx-xxxxxxxxxxxxxxx</span>
{
...
"output":"e2ccd204bca37c77c0ba59fc470cd0f7+162",
</code></pre>
</notextile>
-(Your shell should automatically fill in @$USER@ with your login name. The job JSON that gets saved should have @"repository"@ pointed at your personal git repository.)
+(Your shell should automatically fill in @$USER@ with your login name. The job JSON that gets saved should have @"repository"@ pointed at your personal Git repository.)
-Because the job ran in parallel, each instance of parallel-hash creates a separate @md5sum.txt@ as output. Arvados automatically collates theses files into a single collection, which is the output of the job:
+Because the job ran in concurrent, each instance of concurrent-hash creates a separate @md5sum.txt@ as output. Arvados automatically collates theses files into a single collection, which is the output of the job:
<notextile>
-<pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">arv keep ls e2ccd204bca37c77c0ba59fc470cd0f7+162</span>
+<pre><code>~/$USER/crunch_scripts$ <span class="userinput">arv keep ls e2ccd204bca37c77c0ba59fc470cd0f7+162</span>
./md5sum.txt
-~/<b>you</b>/crunch_scripts$ <span class="userinput">arv keep get e2ccd204bca37c77c0ba59fc470cd0f7+162/md5sum.txt</span>
+~/$USER/crunch_scripts$ <span class="userinput">arv keep get e2ccd204bca37c77c0ba59fc470cd0f7+162/md5sum.txt</span>
0f1d6bcf55c34bed7f92a805d2d89bbf alice.txt
504938460ef369cd275e4ef58994cffe bob.txt
8f3b36aff310e06f3c5b9e95678ff77a carol.txt
</code></pre>
</notextile>
-
-
projects / arvados.git / blobdiff