---
layout: default
navsection: api
navmenu: API Methods
title: "jobs"

...



Required arguments are displayed in %{background:#ccffcc}green%.


h2. cancel

cancel jobs

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
{background:#ccffcc}.|uuid|string||path||

h2(#create). create

Create a new Job.

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
{background:#ccffcc}.|job|object|See "Job resource":{{site.baseurl}}/schema/Job.html|request body||
|minimum_script_version |string     |Git branch, tag, or commit hash specifying the minimum acceptable script version (earliest ancestor) to consider when deciding whether to re-use a past job.|query|@c3e86c9@|
|exclude_script_versions|array of strings|Git commit branches, tags, or hashes to exclude when deciding whether to re-use a past job.|query|@["8f03c71","8f03c71"]@|
|find_or_create         |boolean    |Before creating, look for an existing job that has identical script, script_version, and script_parameters to those in the present job, has nondeterministic=false, and did not fail (it could be queued, running, or completed). If such a job exists, respond with the existing job instead of submitting a new one.|query|@false@|

When a job is executed, the 'script_version' field is resolved to an exact Git revision and the Git hash for that revision is recorded in 'script_version'.  If 'script_version' can't be resolved, the job submission will be rejected.

h3. Reusing jobs

Because Arvados records the exact version of the script, input parameters, and runtime environment [1] that was used to run the job, if the script is deterministic (meaning that the same code version is guaranteed to produce the same outputs from the same inputs) then it is possible to re-use the results of past jobs, and avoid re-running the computation to save time.  Arvados uses the following algorithm to determine if a past job can be re-used:

notextile. <div class="spaced-out">

# If 'find_or_create' is false or omitted, create a new job and skip the rest of these steps.
# Find a list of acceptable values for 'script_version'.  If 'minimum_script_version' is specified, this is the set of all revisions in the Git commit graph between 'minimum_script_version' and 'script_version' (inclusive) [2].  If 'minimum_script_version' is not specified, only 'script_version' is added to the list.  If 'exclude_script_versions' is specified, the listed versions are excluded from the list.
# Select jobs whose 'script' and 'script_parameters' attributes match the submitted job, and whose 'script_version' attribute is in the list of acceptable versions.  Exclude jobs that failed or set 'nondeterministic' to true.
# If more than one of candidate jobs has finished, check that all such jobs actually did produce the same output.
# If existing jobs exist and do not disagree with one another about the correct output, re-use one of the selected past jobs. If there is more than one match, which job will be returned is undefined.
# If an existing job could not be chosen this way, create a new job.

fn1. As of this writing, versioning the runtime environment is still under development.

fn2. This may include parallel branches if there is more than one path between 'minimum_script_version' and 'script_version' in the Git commit graph.  Use 'exclude_script_versions' to blacklist specific versions.

</div>

h3. Examples

Run the script "crunch_scripts/hash.py" in the repository "you" using the "master" commit.  Arvados should re-use a previous job if the script_version of the previous job is the same as the current "master" commit. This works irrespective of whether the previous job was submitted using the name "master", a different branch name or tag indicating the same commit, a SHA-1 commit hash, etc.

<notextile><pre>
{
  "job": {
    "script": "hash.py",
    "repository": "<b>you</b>",
    "script_version": "master",
    "script_parameters": {
      "input": "c1bad4b39ca5a924e481008009d94e32+210"
    }
  },
  "find_or_create": true
}
</pre></notextile>

Run using exactly the version "d00220fb38d4b85ca8fc28a8151702a2b9d1dec5". Arvados should re-use a previous job if the "script_version" of that job is also "d00220fb38d4b85ca8fc28a8151702a2b9d1dec5".

<notextile><pre>
{
  "job": {
    "script": "hash.py",
    "repository": "<b>you</b>",
    "script_version": "d00220fb38d4b85ca8fc28a8151702a2b9d1dec5",
    "script_parameters": {
      "input": "c1bad4b39ca5a924e481008009d94e32+210"
    }
  },
  "find_or_create": true
}
</pre></notextile>

Arvados should re-use a previous job if the "script_version" of the previous job is between "earlier_version_tag" and the "master" commit (inclusive), but not the commit indicated by "blacklisted_version_tag". If there are no previous jobs matching these criteria, run the job using the "master" commit.

<notextile><pre>
{
  "job": {
    "script": "hash.py",
    "repository": "<b>you</b>",
    "script_version": "master",
    "script_parameters": {
      "input": "c1bad4b39ca5a924e481008009d94e32+210"
    }
  },
  "minimum_script_version": "earlier_version_tag",
  "exclude_script_versions": ["blacklisted_version_tag"],
  "find_or_create": true
}
</pre></notextile>

Run the script "crunch_scripts/monte-carlo.py" in the repository "you" using the current "master" commit. Because it is marked as "nondeterministic", this job will not be considered as a suitable candidate for future job submissions that use the "find_or_create" feature.

<notextile><pre>
{
  "job": {
    "script": "monte-carlo.py",
    "repository": "<b>you</b>",
    "script_version": "master",
    "nondeterministic": true,
    "script_parameters": {
      "input": "c1bad4b39ca5a924e481008009d94e32+210"
    }
  }
}
</pre></notextile>

h2. delete

Delete an existing Job.

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
{background:#ccffcc}.|uuid|string|The UUID of the Job in question.|path||

h2. get

Gets a Job's metadata by UUID.

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
{background:#ccffcc}.|uuid|string|The UUID of the Job in question.|path||

h2. list

List jobs.

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
|limit|integer (default 100)|Maximum number of jobs to return.|query||
|order|string|Order in which to return matching jobs.|query||
|filters|array|Conditions for filtering jobs.|query||

h2. log_tail_follow

log_tail_follow jobs

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
{background:#ccffcc}.|uuid|string||path||
|buffer_size|integer (default 8192)||query||

h2. queue

queue jobs

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
|order|string||query||
|filters|array||query||

h2. update

Update attributes of an existing Job.

Arguments:

table(table table-bordered table-condensed).
|_. Argument |_. Type |_. Description |_. Location |_. Example |
{background:#ccffcc}.|uuid|string|The UUID of the Job in question.|path||
|job|object||query||