Required retention policy for Y-build artifacts

[HannesWell]

In the context of unifying the clean-up jobs in the RelEng Jenkins instance (#3322) and generally refining the preparation of a new release cycle I stumbled upon the question for how long Y-builds, i.e. the drops and the corresponding p2 repos are actually required and should be retained.

The release notes explain that the Y-builds should be retained if a new release happens shortly after the Eclipse release (usually for odd versions):

eclipse.platform.releng.aggregator/RELEASE.md

Lines 122 to 123 in c9fd1cc

	- For the Y and P build parameters it's important to know whether or not Y and P builds were run during the release. Since they correspond to java releases on a 6 month cycle, typically they are built in odd-numbered releases.
	The existing builds are kept for one release, then cleaned up before the next stream that will have Y and P builds. it's convoluted and I dont want to type it out. Remove Y builds on even releases.

Which matches what has been explained in #3273 (comment).
And given that P-builds are now handled by JDT directly in the JDT JIPP and download space, I think we can disregard P-builds from further discussions.

This leads me to the following more specific questions:

• For how long should are the Y-build drops at the download page are needed and should be retained?
  For I-builds only all the drops younger than five days are retained and for older I-builds of the current release, only one per week (roughly summarized). Would something similar also fit for Y-build drops? At the moment I cannot tell what actually cleans-up the Y-build drops (but it could be aligned with [Build] Unify clean-ups jobs as Jenkins pipelines and inline scripts #3322).

  • https://download.eclipse.org/eclipse/downloads/YIndex.php
  • https://download.eclipse.org/eclipse/downloads/drops4/Y20250909-1000/

• How long should the Y-build p2-repos be retained?

  • According to the doc linked above and my understand of the process, generally some time after the Java-release (i.e. the composite)
  • But are all p2 repos of all builds required until after the release or are you just interested in the latest build's repos anyways (e.g. the last five or so)? Especially as you keep the relevant bundles in the jdt/P-builds repo any ways.
  • And for how long are they required after the release?
    In the past the Y-build repos have been deleted a year later.

• Are the Y-build drops for Equinox actually interesting for anybody or can they be removed?

  • https://download.eclipse.org/equinox/drops/Y20250911-1000/

And besides the general questions above, I wonder specifically if the old 4.XX-Y-builds, 4.XX-P-builds or 4.XX-P-builds-old directories/composite repositories are still required in the Eclipse downloads area or can be deleted?
I assume the eclipse/updates/P-builds composite can be deleted too?

@stephan-herrmann, @mpalat, @jarthana could you help me by answering these questions? I'm trying to find elegant solutions to clean up Y-builds automatically as far as possible while respecting JDT's demands for releasing the ECJ-patches when new Java versions are released.

[mpalat]

• For how long should are the Y-build drops at the download page are needed and should be retained?

I think older Y builds can be removed after the next milestone. if a P build is for 4.x for a Java Version "100", then 4.x+1 will contain that code for Java Version 100 support. I think its reasonable to remove all Y builds after the 4.x+1 release. ie, all Y builds for Java 25 can be removed after Eclipse 4.38 release.

For I-builds only all the drops younger than five days are retained and for older I-builds of the current release, only one per week (roughly summarized). Would something similar also fit for Y-build drops? At the moment I cannot tell what actually cleans-up the Y-build drops (but it could be aligned with [Build] Unify clean-ups jobs as Jenkins pipelines and inline scripts #3322).

• https://download.eclipse.org/eclipse/downloads/YIndex.php

• https://download.eclipse.org/eclipse/downloads/drops4/Y20250909-1000/

• How long should the Y-build p2-repos be retained?

  • According to the doc linked above and my understand of the process, generally some time after the Java-release (i.e. the composite)

Same formula of 4.x+1 should be ok here unless @stephan-herrmann / @jarthana have other inputs.

• But are all p2 repos of all builds required until after the release or are you just interested in the latest build's repos anyways (e.g. the last five or so)? Especially as you keep the relevant bundles in the jdt/P-builds repo any ways.

• And for how long are they required after the release?
  In the past the Y-build repos have been deleted a year later.

• Are the Y-build drops for Equinox actually interesting for anybody or can they be removed?

  • https://download.eclipse.org/equinox/drops/Y20250911-1000/

And besides the general questions above, I wonder specifically if the old 4.XX-Y-builds, 4.XX-P-builds or 4.XX-P-builds-old directories/composite repositories are still required in the Eclipse downloads area or can be deleted?

same as above - am fine to remove after 4.x+1

@stephan-herrmann, @mpalat, @jarthana could you help me by answering these questions? I'm trying to find elegant solutions to clean up Y-builds automatically as far as possible while respecting JDT's demands for releasing the ECJ-patches when new Java versions are released.

@HannesWell - Please find my thoughts on some of the questions above inlined.

[HannesWell]

Thank you for your answers, that already helps, but I have still have some follow-up question.

• For how long should are the Y-build drops at the download page are needed and should be retained?

I think older Y builds can be removed after the next milestone. if a P build is for 4.x for a Java Version "100", then 4.x+1 will contain that code for Java Version 100 support. I think its reasonable to remove all Y builds after the 4.x+1 release. ie, all Y builds for Java 25 can be removed after Eclipse 4.38 release.

Just for clarification, I'm talking about the build pages/drops at the download page that are e.g. listed at https://download.eclipse.org/eclipse/downloads/YIndex.php.
For example: https://download.eclipse.org/eclipse/downloads/drops4/Y20250916-1440/
At the moment I'm not talking about the Y-build p2 repos, e.g. within https://download.eclipse.org/eclipse/updates/4.37-Y-builds/

Would it also be fine for you to keep only the drops/pages of a limited number of the latest Y-builds (e.g. the last five or if you need more ten)?
These pages are quite large, about 6GB per build (while the p2-repo is only a bit below 600MB). Therefore for I-builds we also just keep the most recent five builds plus the drop of the first stable build. But as Y-builds have different due-dates when a java release is about to happen it would complicate the automated clean-up (e.g. in #3322) a lot when the same logic would be implemented for Y-builds.

I cannot tell if old Y-build pages (like https://download.eclipse.org/eclipse/downloads/drops4/Y20250909-1000/) are of interest for you? When developing ECJ for a new Java version are you only interested in the latest test results (and check them regularly) or also in results of older builds?

Currently all Y-build drops/download pages that were created before an Eclipse release are deleted shortly after the Eclipse release (in the clean-up of release artifacts), regardless of if a java release is about to happen or not. Since I'm not aware of any complaint about this practice I have the impression you are generally not interested in older download pages/drops.

And besides the general questions above, I wonder specifically if the old 4.XX-Y-builds, 4.XX-P-builds or 4.XX-P-builds-old directories/composite repositories are still required in the Eclipse downloads area or can be deleted?

same as above - am fine to remove after 4.x+1

OK, thanks then I will delete the older ones now.

Are the Y-build drops for Equinox actually interesting for anybody or can they be removed?

* https://download.eclipse.org/equinox/drops/Y20250911-1000/

I'm not sure if this has been answered, but I don't think there is any value for Y-builds of Equinox? Therefore I believe the Equinox drops for Y-builds are useless.

[HannesWell]

Just for clarification, I'm talking about the build pages/drops at the download page that are e.g. listed at https://download.eclipse.org/eclipse/downloads/YIndex.php.
Would it also be fine for you to keep only the drops/pages of a limited number of the latest Y-builds (e.g. the last five or if you need more ten)?

@mpalat, @jarthana or @stephan-herrmann any objections or would you be fine with a fixed number of Y-build download drops (not p2 repos).