[JENKINS-16490] New versions of Remoting should be automatically pushed to Java Web Start agents

[timja]

As described in JENKINS-9679, merely updating the version of slave.jar served from Jenkins master does not cause JNLP agents to use the new version; they persist in using the JNLP cache. This makes debugging changes difficult, and can result in bug fixes seeming to not take effect in user deployments.

We do set an immediate Expires header on /jnlpJars/slave.jar but apparently this does not suffice.

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Originally reported by jglick, imported from: New versions of Remoting should be automatically pushed to Java Web Start agents

• status: Open
• priority: Major
• resolution: Unresolved
• imported: 2022/01/10

[timja]

jglick:

There should also be a NodeMonitor for slaves running an old version of slave.jar.

[timja]

danielbeck:

Jesse: It's called VersionColumn Plugin

[timja]

jglick:

Ah, how about that!

[timja]

oleg_nenashev:

I also think that Jenkins should have an extension point, which allows to provide custom slave.jar version to users.

Use-cases:

• Apply a patch for client-side without the master's restart
• Use custom builds with modified default values, etc. (our users don't like following internal guides)

[timja]

cobexer:

I remember reading in another thread that jenkins-slave.exe is updated automatically, couldn't it take care of updating the slave.jar too?

Another idea: would a redirect of the /jnlpJars/slave.jar to /jnlpJars/slave-vx.xxx.x.jar help?

Last time the slave.jar had to be updated i had to learn powershell and write a script that deployed the new slave.jar across all our windows slaves - that was frustrating and took way too long for something that ought to be built in.

[timja]

heymjo:

Arriving here after installing Version Column Plugin because it was featured in Plugin Spotlight on the jenkins homepage. After jenkins restart all our windows nodes were marked offline because of outdated slave.jar, fun times clicking on all of them to mark them back online Anyone found a way to force an update on JNLP slaves somehow ?

[timja]

oleg_nenashev:

heymjo, are you using Windows service on Windows? If yes, I'm working on such feature for WinSW

[timja]

heymjo:

Yes we are using windows service.

[timja]

oleg_nenashev:

Created JENKINS-39237 as a follow-up for Windows slaves. I hope to deliver it shortly

[timja]

oleg_nenashev:

The feature for Windows service agents has been delivered in Jenkins 2.50.
Regarding the pure agents, it is still TODO

[timja]

oleg_nenashev:

WinSW changes are not the LTS candidate. Whatever needs to be done for other agent types, it won't be an LTS candidate as well. And this issue is actually not a bug anyway. It's architecture flaw, but still an improvement/new feature

[timja]

[Originally duplicated by: JENKINS-21642]

[timja]

[Originally duplicated by: JENKINS-22454]

[timja]

[Originally duplicated by: JENKINS-23880]

[timja]

[Epic: JENKINS-44099]