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https://issues.apache.org/jira/browse/PHOENIX-4018?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16089865#comment-16089865
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Ankit Singhal edited comment on PHOENIX-4018 at 7/17/17 2:05 PM:
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Yes, only last scanner should update the progress(which you can do easily in
BaseScannerRegionObserver.RegionScannerHolder#next(List<Cell>,ScannerContext)),
Heartbeat problem is still tricky, if we update the time progress in the last
scanner then it can be too late and RPC may timeout in between. If we do it
between the scanners , I'm not sure how our scanners will handle the empty
values.
was (Author: an...@apache.org):
Yes, only last scanner should update the progress(which you can do easily in
BaseScannerRegionObserver.RegionScannerHolder#next(List<Cell>,ScannerContext)),
HeartBeat will also work fine if we do update the time progress in the same
manner.
> HashJoin may produce nulls for LHS table columns
> ------------------------------------------------
>
> Key: PHOENIX-4018
> URL: https://issues.apache.org/jira/browse/PHOENIX-4018
> Project: Phoenix
> Issue Type: Bug
> Affects Versions: 4.11.0
> Reporter: Sergey Soldatov
> Assignee: Sergey Soldatov
> Priority: Critical
> Attachments: PHOENIX-4018-1.patch
>
>
> Here is the problem: in HashJoinRegionScanner methods (nextRow for example)
> we are using the same scanner context that was created in RSRpcServices. It
> has limits (i.e. 2Mb size). Let's say that we have 3Mb region and the only
> key that match the join condition is located at the end of the region. In
> HashJoinRegionScanner#nextRow when we iterate through the region rows once we
> reached the limit of 2Mb, every region scanner nextRow will return a single
> cell and the scanner context will have SIZE_LIMIT_REACHED_MID_ROW state. But
> we don't have any logic that check that, so this single cell is considered as
> a complete row with all nulls except one column.
> How to fix it:
> 1. for region scanner we may provide NoLimitScannerContext, so we will never
> get a partial result.
> 2. We need to update the scanner context that we got from RSRpcServices with
> the real data, basing on the size of results we are going to return.
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