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https://issues.apache.org/jira/browse/SLING-3386?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13898791#comment-13898791
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Chetan Mehrotra commented on SLING-3386:
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bq. treat logging specially in that we define a new "folder" which is handled
first by the bootstrap installer
The patch takes a bit different route but aim is same i.e. enable influencing
the order in which bootstrap installer would install bundle files
bq. move all non-logging bundles from startlevel 1 to startlevel 2
That would be the proper and stable fix. However it would cause issue in case
of upgrades as we would have to change the bundle start levels. Such a change
would require lot more effort and we would need to ensure that all cases are
handled properly. Thats the reason I am taking the proposed approach as it is a
small change in current startup process. And yes this fix would also not handle
the upgrade scenario
bq. The BundleStartLevelSorter.parseStartOrder may throw an exception if the
header happens to not be an Integer.
I thought about that but then I preferred to have a fail fast approach where if
there is a problem in value then it gets noticed right away.
bq. Also every reference to start order (or even start level in that method)
would have to be rephrased to install order. Also, I would call the header
"X-Sling-Bootstrap-Install-Order" to indicate it is just the bootstrap
installer respecting this as the installation order.
Ack. Would change that.
> Enable support starting bundle in custom oreder at start level 1
> ----------------------------------------------------------------
>
> Key: SLING-3386
> URL: https://issues.apache.org/jira/browse/SLING-3386
> Project: Sling
> Issue Type: Improvement
> Components: Launchpad
> Affects Versions: Launchpad Base 2.5.0
> Reporter: Chetan Mehrotra
> Priority: Minor
> Attachments: SLING-3386.patch
>
>
> By default OSGi framework does not define the order in which bundles would be
> started in a given start level. The only way is to use to use start level.
> However in case of bundle like Logging its desriable that Log bundle is the
> first bundle to start in the system such that it does not miss any log
> message. The problem is described in more details at SLING-3340.
> As Sling uses Felix framework by default it is possible to control the start
> order by controlling the order in which bundles are installed on the
> framework. As per current Felix Framework implementation [1] bundle within
> same start level are started in the order of bundleId.
> The way patch works is
> 1. Bundle which start at start level 1 can define a header
> 'X-Sling-Start-Order' to provide a start order hint. Lower the level then
> earlier the bundle would be started
> 2. BootstrapInstaller would sort the files obtained from directly listing
> based on this header.
> 3. Sorted list would be used to install the bundles
> I understand that this is a very much implementation specific fix and might
> not work if Felix changes the internal logic. But then the feature is meant
> to be used in best effort basis!!.
> [1]
> https://github.com/apache/felix/blob/trunk/framework/src/main/java/org/apache/felix/framework/Felix.java#L4873
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