Merge branch 'master' into 3219-further-docker-improvements

[arvados.git] / doc / user / topics / tutorial-parallel.html.textile.liquid

diff --git a/doc/user/topics/tutorial-parallel.html.textile.liquid b/doc/user/topics/tutorial-parallel.html.textile.liquid
index 6dbdb8af23a74176e4d8767031e88c4bdbd857ac..d7a093a245085bf650cd6ee9b0ae1896e7313939 100644 (file)
--- a/doc/user/topics/tutorial-parallel.html.textile.liquid
+++ b/doc/user/topics/tutorial-parallel.html.textile.liquid
@@ -6,7 +6,7 @@ title: "Parallel Crunch tasks"
 
 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.
 
-Start by entering the @crunch_scripts@ directory of your git repository:
+Start by entering the @crunch_scripts@ directory of your Git repository:
 
 <notextile>
 <pre><code>~$ <span class="userinput">cd <b>you</b>/crunch_scripts</span>
@@ -17,7 +17,7 @@ Next, using @nano@ or your favorite Unix text editor, create a new file called @
 
 notextile. <pre>~/<b>you</b>/crunch_scripts$ <code class="userinput">nano parallel-hash.py</code></pre>
 
-Add the following code to compute the md5 hash of each file in a 
+Add the following code to compute the MD5 hash of each file in a collection:
 
 <notextile> {% code 'parallel_hash_script_py' as python %} </notextile>
 
@@ -25,7 +25,7 @@ Make the file executable:
 
 notextile. <pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">chmod +x parallel-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>
@@ -40,7 +40,7 @@ You should now be able to run your new script using Crunch, with "script" referr
 <pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">cat &gt;~/the_job &lt;&lt;EOF
 {
  "script": "parallel-hash.py",
- "repository": "<b>you</b>",
+ "repository": "$USER",
  "script_version": "master",
  "script_parameters":
  {
@@ -63,13 +63,13 @@ EOF</span>
 </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.)
+
 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:
 
 <notextile>
 <pre><code>~/<b>you</b>/crunch_scripts$ <span class="userinput">arv keep ls e2ccd204bca37c77c0ba59fc470cd0f7+162</span>
-md5sum.txt
-md5sum.txt
-md5sum.txt
+./md5sum.txt
 ~/<b>you</b>/crunch_scripts$ <span class="userinput">arv keep get e2ccd204bca37c77c0ba59fc470cd0f7+162/md5sum.txt</span>
 0f1d6bcf55c34bed7f92a805d2d89bbf alice.txt
 504938460ef369cd275e4ef58994cffe bob.txt