[
https://issues.apache.org/jira/browse/OAK-4293?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15399257#comment-15399257
]
Alex Parvulescu edited comment on OAK-4293 at 8/8/16 2:49 PM:
--------------------------------------------------------------
I started implementing a persisted gc journal that would contain the size
post-cleanup which can be used as a reference for growth estimation:
https://github.com/stillalex/jackrabbit-oak/commit/eb7d4c17a352cc837d8d441c8ddc490fab95c3e2
not completely tied to the compaction estimation, this can also be used by the
upper layers (JMX bindings perhaps) to surface the compaction history (and repo
sizes delta since last compaction) and possibly allow someone to manually
trigger compaction if they think necessary.
patch only contains the journal persisting bits, the info is not used yet.
[~mduerig] thoughts?
was (Author: alex.parvulescu):
I started implementing a persisted gc journal that would contain the size
post-cleanup which can be used as a reference for growth estimation:
https://github.com/stillalex/jackrabbit-oak/commit/d8a9a756df9c3e1414cfb554264122216fb6e73e
not completely tied to the compaction estimation, this can also be used by the
upper layers (JMX bindings perhaps) to surface the compaction history (and repo
sizes delta since last compaction) and possibly allow someone to manually
trigger compaction if they think necessary.
patch only contains the journal persisting bits, the info is not used yet.
[~mduerig] thoughts?
> Refactor / rework compaction gain estimation
> ---------------------------------------------
>
> Key: OAK-4293
> URL: https://issues.apache.org/jira/browse/OAK-4293
> Project: Jackrabbit Oak
> Issue Type: Task
> Components: segment-tar
> Reporter: Michael Dürig
> Assignee: Alex Parvulescu
> Labels: gc
> Fix For: Segment Tar 0.0.10
>
> Attachments: size-estimation.patch
>
>
> I think we have to take another look at {{CompactionGainEstimate}} and see
> whether we can up with a more efficient way to estimate the compaction gain.
> The current implementation is expensive wrt. IO, CPU and cache coherence. If
> we want to keep an estimation step we need IMO come up with a cheap way (at
> least 2 orders of magnitude cheaper than compaction). Otherwise I would
> actually propose to remove the current estimation approach entirely
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
