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https://issues.apache.org/jira/browse/OAK-5046?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15629467#comment-15629467
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Alex Parvulescu edited comment on OAK-5046 at 11/2/16 4:47 PM:
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The provided patch has 2 problems:
* first setting the {{gainThreshold}} to {{0}} will disable estimation
completely [0]. not good.
* second it doesn't switch the default estimation impl over to the new
estimation approach.
have you tested what estimation method (if any) is used with this patch?
To further clarify, removing this default means that the size based estimation
must be used, so take care of updating the defaults to sensible values, ie.
{{GAIN_THRESHOLD_DEFAULT}} to {{-1}} and {{SIZE_DELTA_ESTIMATION_DEFAULT}} to a
few gigs, not sure how much. [~mduerig] you are welcome to chime in for default
values here!
One of the goals of this issue is also that if nothing is set (threshold or
size), the size based compaction must be used. Also, skip estimation if the
size value is {{0}} to keep existing way to switch off estimation if needed [0].
[0]
https://github.com/apache/jackrabbit-oak/blob/trunk/oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java#L742
was (Author: alex.parvulescu):
The provided patch has 2 problems:
* first setting the {{gainThreshold}} to {{0}} will disable estimation
completely. not good.
* second it doesn't switch the default estimation impl over to the new
estimation approach.
have you tested what estimation method (if any) is used with this patch?
> Remove the old estimation OSGi setting (compaction.gainThreshold)
> -----------------------------------------------------------------
>
> Key: OAK-5046
> URL: https://issues.apache.org/jira/browse/OAK-5046
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: segment-tar
> Affects Versions: 1.5.12
> Reporter: Andrei Dulceanu
> Assignee: Andrei Dulceanu
> Priority: Minor
> Labels: osgi-config
> Fix For: 1.5.13
>
> Attachments: OAK-5046-01.patch
>
>
> Currently, there are two implementations for finding out the gain in
> repository size after running compaction: the old one,
> {{CompactionGainEstimate}} and the new one, {{SizeDeltaGcEstimation}}.
> Similarly, there are also two configurations for customising them, in
> {{SegmentNodeStoreService}}, {{compaction.gainThreshold}} and
> {{compaction.sizeDeltaEstimation}}.
> At the moment both of them are exposed as OSGi configurations, but only the
> new one should be exposed (e.g. {{compaction.sizeDeltaEstimation}}).
> It must be evaluated whether it makes sense to keep the logic associated with
> the old implementation.
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