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https://issues.apache.org/jira/browse/OAK-2472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15059679#comment-15059679
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Davide Giannella commented on OAK-2472:
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[~lbyrum]
bq. So we have a couple of use cases where it is highly expected that we can
have multiple threads updating the same count
It should not be an issue at all. Our ITs cover an update of the same counter
from 100 concurrent threads. There should not be any failures and no need to
deal with locks that would not than scale. Of course if anything breaks, please
report.
https://github.com/apache/jackrabbit-oak/blob/trunk/oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/AtomicCounterIT.java#L60
bq. Alternately, we saw in the docs and code that there were some plans where
not just oak:increment was recognized, but oak:increment-UUID was recognized.
What docs are you referring to? Please ignore any technical details attached to
jira issues as they are implementation details on who Oak achieve the atomic
counter. From an end-user POV the only docs so far are the javadoc. Will
produce some more docs once the feature will be completed for cluster.
http://jackrabbit.apache.org/oak/docs/apidocs/org/apache/jackrabbit/oak/plugins/atomic/AtomicCounterEditor.html
[~masonw]
bq. If you look at the attached spec from OAK-2220...
Don't. That's a summary of discussions we, oak team, had in order to approach
the problem. They are technical details and as a end-user you should not be
worried about those.
bq. That said, if thread1 sets oak:increment to 1 and thread2 simultaneously
sets oak:increment to 2, then regardless of which order they actually commit
in, since oak:increment is never actually saved, but just used to update
oak:counter, I think the result will always be oak:counter+=3
yes it is.
> Add support for atomic counters on cluster solutions
> ----------------------------------------------------
>
> Key: OAK-2472
> URL: https://issues.apache.org/jira/browse/OAK-2472
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: core
> Affects Versions: 1.3.0
> Reporter: Davide Giannella
> Assignee: Davide Giannella
> Labels: scalability
> Fix For: 1.4
>
> Attachments: atomic-counter.md
>
>
> As of OAK-2220 we added support for atomic counters in a non-clustered
> situation.
> This ticket is about covering the clustered ones.
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