[
https://issues.apache.org/jira/browse/PHOENIX-5494?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16975073#comment-16975073
]
Kadir OZDEMIR commented on PHOENIX-5494:
----------------------------------------
[~comnetwork], Thank you for suggestions and the patch. I agree on most of your
points. However, I do not think we can apply this optimization to the reply
writes. The reply writes can have cells with different timestamps and can have
multiple mutations for the same row key within a batch. Regarding the
concurrency issues for regular writes, they are taken care by the existing row
locks and using ConcurrentHashSet.
> Batched, mutable Index updates are unnecessarily run one-by-one
> ---------------------------------------------------------------
>
> Key: PHOENIX-5494
> URL: https://issues.apache.org/jira/browse/PHOENIX-5494
> Project: Phoenix
> Issue Type: Improvement
> Reporter: Lars Hofhansl
> Assignee: Kadir OZDEMIR
> Priority: Major
> Labels: performance
> Attachments: 5494-4.x-HBase-1.5.txt,
> PHOENIX-5494-4.x-HBase-1.4.patch, PHOENIX-5494.master.001.patch,
> PHOENIX-5494.master.002.patch, PHOENIX-5494.master.003.patch,
> Screenshot_20191110_160243.png, Screenshot_20191110_160351.png,
> Screenshot_20191110_161453.png
>
> Time Spent: 1h 20m
> Remaining Estimate: 0h
>
> I just noticed that index updates on mutable tables retrieve their deletes
> (to invalidate the old index entry) one-by-one.
> For batches, this can be *the* major time spent during an index update. The
> cost is mostly incured by the repeated setup (and seeking) of the new region
> scanner (for each row).
> We can instead do a skip scan and get all updates in a single scan per region.
> (Logically that is simple, but it will require some refactoring)
> I won't be getting to this, but recording it here in case someone feels
> inclined.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
