Rundeck multiple job executions, queued or discarded? - rundeck

Question

Rundeck docs for creating a job,
https://docs.rundeck.com/docs/manual/creating-jobs.html#creating-a-job
says:
Multiple Executions
By default, a job runs as a "Single Execution" -- it can only have a single execution running at a time. This is useful if the steps the Job performs might be interfered with if another separate process was also performing them on the same Node(s).
However, in some cases it is useful to allow a Job to be executed more than once simultaneously.
You can make a job allow "Multiple Executions" by toggling the value to Yes in the Job editor field shown below:
my questions:
For the default "Single Execution" mode, what happens to subsequent simultaneous job runs? Are they discarded or queued?
For "Multiple Execution" mode, what happens to subsequent simultaneous job runs that exceed the "Max number of multiple executions"? Are they discarded or queued?
Thanks for any guidance.

Answer 1

You can test with a simple job definition like this:
<joblist>
<job>
<defaultTab>nodes</defaultTab>
<description></description>
<executionEnabled>true</executionEnabled>
<id>72fe54d5-26da-4cd4-a487-0955bd3b7f67</id>
<loglevel>INFO</loglevel>
<name>HelloWorld</name>
<nodeFilterEditable>false</nodeFilterEditable>
<plugins />
<scheduleEnabled>true</scheduleEnabled>
<sequence keepgoing='false' strategy='node-first'>
<command>
<exec>sleep 15; echo "hello"</exec>
</command>
</sequence>
<uuid>72fe54d5-26da-4cd4-a487-0955bd3b7f67</uuid>
</job>
</joblist>
In case of execute again the job you can see this error.
So, if you modify the job to allowing "two multiple execution" you can see that works normally with 2 executions of the same job:
<joblist>
<job>
<defaultTab>nodes</defaultTab>
<description></description>
<executionEnabled>true</executionEnabled>
<id>72fe54d5-26da-4cd4-a487-0955bd3b7f67</id>
<loglevel>INFO</loglevel>
<maxMultipleExecutions>2</maxMultipleExecutions>
<multipleExecutions>true</multipleExecutions>
<name>HelloWorld</name>
<nodeFilterEditable>false</nodeFilterEditable>
<plugins />
<scheduleEnabled>true</scheduleEnabled>
<sequence keepgoing='false' strategy='node-first'>
<command>
<exec>sleep 15; echo "hello"</exec>
</command>
</sequence>
<uuid>72fe54d5-26da-4cd4-a487-0955bd3b7f67</uuid>
</job>
</joblist>
But if you execute three times the same job, you can see the same error of first scenario.
Short answer: if you exceed the default value or defined value, the execution is discarded.