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https://issues.apache.org/jira/browse/OAK-1159?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13830151#comment-13830151
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Jukka Zitting commented on OAK-1159:
------------------------------------
Blob copying fixed in revision 1544610.
There should be no need for the {{SegmentNodeStore}} around the {{FileStore}}
instance. For the initial backup you'd just need to add the extra initial state
argument as discussed. And for incremental backup the following piece of code
should be enough:
{code}
NodeState before = store.retrieve(checkpoint);
checkpoint = store.checkpoint(...);
NodeState after = store.retrieve(checkpoint);
FileStore backup = new FileStore(...);
Journal root = backup.getJournal("root");
SegmentNodeState state = new SegmentNodeState(
backup.getWriter().getDummySegment(), root.getHead());
SegmentRootBuilder builder = state.builder();
after.compareAgainstBaseState(before, new ApplyDiff(builder));
root.setHead(builder.getNodeState().getRecordId());
backup.close();
{code}
The idea is that we keep track of the checkpoint that was last backed up, and
then use the {{ApplyDiff}} class to copy all the changes since then to the
backup.
> Backup and restore
> ------------------
>
> Key: OAK-1159
> URL: https://issues.apache.org/jira/browse/OAK-1159
> Project: Jackrabbit Oak
> Issue Type: New Feature
> Components: core, mk
> Reporter: Michael Marth
> Assignee: Alex Parvulescu
>
> We need a way to backup and restore a repository. I was thinking that the MK
> impl could expose an interface for this, as the actual implementation would
> differ quite a bit between e.g. TarMK and MongoMK.
> Also, I think we could leverage the MVCC nature of the MKs and mark a
> specific revision as "the revision to backup" (regardless of ongoing writes).
> That would allow us to prevent the ugly situation in JR2, that we need to
> stop writes for a while to produce a consistent backup.
> The restore in such a scenario would discard revisions that happened after
> said marker (but still made it into the backup).
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