clean whipe out all bundle data

[laeubi]

On the help page it says:

osgi.clean
if set to "true", any cached data used by the OSGi framework and eclipse runtime will be wiped clean. This will clean the caches used to store bundle dependency resolution and eclipse extension registry data. Using this option will force eclipse to reinitialize these caches.

In fact this does not really clear out only cached data but also the "persistent bundle area" a bundle get when calling org.osgi.framework.BundleContext.getDataFile(String) this is also where the configuration admin usually stores data, so also all user-configuration get wiped when using -clean

Currently this won't be noticed much as eclipse uses it own "preferences" that are stored in the workspace and Plugins are using Platform.getStateLocation(bundle), but this is of course not an option for "pure" OSGi components that don't want to bind to Eclipse specific things.

[laeubi]

Looking at https://docs.osgi.org/specification/osgi.core/8.0.0/framework.lifecycle.html#i1236436 I also can't find an indication that the data there is considered only a cache ("private persistent storage area").

[tjwatson]

The bundle data area lives with the installation of a bundle. When a bundle is no longer installed then its bundle data area must also be removed. When using -clean all bundles effectively are no longer installed. This is the same when you use the framework launch option https://docs.osgi.org/javadoc/osgi.core/8.0.0/org/osgi/framework/Constants.html#FRAMEWORK_STORAGE_CLEAN_ONFIRSTINIT

[laeubi]

Given that P2 / SimpleInstaller sometimes mess up things and we recommend to call clean it seems there might then be an option required to flush cached state but retain the bundle data (e.g. by only clear items that are really uninstalled, e.g. bundle location has changed or version or symbolic name) and better document that this not really clears cached data (what one usually reads as "data that can be recovered from other sources") but wipes out even persistent data.

[tjwatson]

Given that P2 / SimpleInstaller sometimes mess up things and we recommend to call clean it seems there might then be an option required to flush cached state but retain the bundle data (e.g. by only clear items that are really uninstalled, e.g. bundle location has changed or version or symbolic name) and better document that this not really clears cached data (what one usually reads as "data that can be recovered from other sources") but wipes out even persistent data.

This will not be how other compliant frameworks behave and I think it would violate the specification. Bundle data is associated with an installed bundle which has a location + bundle ID (long) value associated with it. When doing -clean we could have the same bundle locations, but the bundle ID may very likely change from the previous state we cleaned.

[laeubi]

So osgi.clean / -clean is effectively org.osgi.framework.storage.clean=onFirstInit, I'm just asking because I can't find osgi.clean in the spec, and at least the Eclipse doc seem to indicate a different purpose (cleaning cached data) that what org.osgi.framework.storage.clean indocates (clearing the persistent storage area).

[tjwatson]

osgi.clean is Equinox specific and predates the spec'ed onFirstInit. If onFirstInit is used we always end up setting osgi.clean to true:

equinox/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/framework/EquinoxConfiguration.java

Lines 334 to 337 in fa2001e

	// set other defaults
	if (FRAMEWORK_STORAGE_CLEAN_ONFIRSTINIT.equals(getConfiguration(FRAMEWORK_STORAGE_CLEAN))) {
	setConfiguration(PROP_CLEAN, "true"); //$NON-NLS-1$
	}

This is because other things in Eclipse pay attention to the osgi.clean value, like the extension registry.

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If this issue became irrelevant in the meantime please close it as completed. If it is still relevant and you think it should be fixed some possibilities are listed below.
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[github-actions]

This issue has been inactive for 180 days and is therefore labeled as stale.
If this issue became irrelevant in the meantime please close it as completed. If it is still relevant and you think it should be fixed some possibilities are listed below.
Please read https://github.com/eclipse-equinox/.github/blob/main/CONTRIBUTING.md#contributing-to-eclipse-equinox for ways to influence development.

[github-actions]

This issue has been inactive for 180 days and is therefore labeled as stale.
If this issue became irrelevant in the meantime please close it as completed. If it is still relevant and you think it should be fixed some possibilities are listed below.
Please read https://github.com/eclipse-equinox/.github/blob/main/CONTRIBUTING.md#contributing-to-eclipse-equinox for ways to influence development.