I have two jobs defined that each build a specific branch (master and 0.0.1) within a github enterprise repo that I'm using for testing.   Build triggering is defined on each one to build when a push is done, and I have configured my github repo with the required webhook.   The webhook is in fact working as the jenkins server logs a message when the webhook POST is received.

The problem is that when I push a commit to either branch (0.0.1 or master), then BOTH jobs are kicked off.   When looking at the polling log info for each of the jobs that are kicked off I see something like this:

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Started on Apr 9, 2018 4:24:11 PM Started by event from 9.209.1.17 ⇒

https://wh-fhir-server-jenkins.swg-devops.com:8443/github-webhook/

on Mon Apr 09 16:24:11 UTC 2018 Workspace is offline. Scheduling a new build to get a workspace. (nonexisting_workspace) Done. Took 0 ms Changes found

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This looks like the git plugin is performing the non-remote polling which requires a workspace, rather than remote polling which would not.  I have not configured the "Force polling using workspace" additional behavior for either of these jobs.

One additional detail...  Build agents are allocated from a docker swarm using a docker container/image which is wiped clean after each build is finished, so each new build effectively gets assigned to a "clean" agent.   For this reason, we cannot use the workspace-based polling and must use the remote polling.

How can I ensure that remote polling is performed by default?   Is there a way to enable additional logging on the Jenkins server to try to determine why the default remote polling is apparently not performed or is perhaps encountering an error?