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https://issues.apache.org/jira/browse/PHOENIX-1751?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15435365#comment-15435365
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Hudson commented on PHOENIX-1751:
---------------------------------

SUCCESS: Integrated in Jenkins build Phoenix-master #1370 (See 
[https://builds.apache.org/job/Phoenix-master/1370/])
PHOENIX-1751 Perform aggregations, sorting, etc, in the preScannerNext 
(jamestaylor: rev 9cc77c8104245a138a62ba251e926e14a74d8c11)
* (add) phoenix-core/src/it/java/org/apache/phoenix/end2end/RenewLeaseIT.java
* (edit) 
phoenix-core/src/main/java/org/apache/phoenix/coprocessor/DelegateRegionScanner.java
* (edit) 
phoenix-core/src/main/java/org/apache/phoenix/coprocessor/BaseScannerRegionObserver.java


> Perform aggregations, sorting, etc, in the preScannerNext instead of 
> postScannerOpen
> ------------------------------------------------------------------------------------
>
>                 Key: PHOENIX-1751
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-1751
>             Project: Phoenix
>          Issue Type: Bug
>            Reporter: Lars Hofhansl
>            Assignee: Lars Hofhansl
>         Attachments: 1751-WIP-v2.txt, 1751-WIP-v2b.patch, 1751-WIP.txt, 
> PHOENIX-1751-v2c.patch, PHOENIX-1751.patch, PHOENIX-1751_v3.patch, 
> PHOENIX-1751_v4.patch
>
>
> HBase retains a lease for every scanner. Then lease expires the scan will no 
> longer (be allowed to) work. The leases guard against the client going away, 
> and allow cleaning up resources if that happens.
> At various points HBase "suspends" the lease while the region server are 
> working on behalf of this scanner, so that the lease won't expire even though 
> the server is working on it.
> HBase does that during the scanning process. Crucially it suspends the leaser 
> after the scanner is opened, before next() is issued on it.
> The outcome of all this is that Phoenix executes aggregates, sorts, etc, with 
> the lease in place, and hence if these take a bit the lease can expire even 
> though the server was working on it.
> Phoenix should do this work in preScannerNext, being careful that the 
> precalculation is only performed once.
> I'll attach a sample patch soon.



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