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https://issues.apache.org/jira/browse/HIVE-24450?focusedWorklogId=518891&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-518891
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ASF GitHub Bot logged work on HIVE-24450:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 02/Dec/20 09:19
Start Date: 02/Dec/20 09:19
Worklog Time Spent: 10m
Work Description: aasha commented on pull request #1718:
URL: https://github.com/apache/hive/pull/1718#issuecomment-737101280
In HA case how will the ordering of events be maintained? Acid Replication
relies on the event sequence. So the ordering needs to be maintained.
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Issue Time Tracking
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Worklog Id: (was: 518891)
Time Spent: 0.5h (was: 20m)
> DbNotificationListener Request Notification IDs in Batches
> ----------------------------------------------------------
>
> Key: HIVE-24450
> URL: https://issues.apache.org/jira/browse/HIVE-24450
> Project: Hive
> Issue Type: Improvement
> Reporter: David Mollitor
> Assignee: David Mollitor
> Priority: Major
> Labels: pull-request-available
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> Every time a new notification event is logged into the database, the sequence
> number for the ID of the even is incremented by one. It is very standard in
> database design to instead request a block of IDs for each fetch from the
> database. The sequence numbers are then handed out locally until the block
> of IDs is exhausted. This allows for fewer database round-trips and
> transactions, at the expense of perhaps burning a few IDs.
> Burning of IDs happens when the server is restarted in the middle of a block
> of sequence IDs. That is, if the HMS requests a block of 10 ids, and only
> three have been assigned, after the restart, the HMS will request another
> block of 10, burning (wasting) 7 IDs. As long as the blocks are not too
> small, and restarts are infrequent, then few IDs are lost.
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