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https://issues.apache.org/jira/browse/HIVE-23236?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Marton Bod updated HIVE-23236:
------------------------------
    Resolution: Won't Do
        Status: Resolved  (was: Patch Available)

> Remove the global lock from acquireLock
> ---------------------------------------
>
>                 Key: HIVE-23236
>                 URL: https://issues.apache.org/jira/browse/HIVE-23236
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Marton Bod
>            Assignee: Marton Bod
>            Priority: Major
>         Attachments: HIVE-23236.1.patch, HIVE-23236.2.patch, 
> HIVE-23236.2.patch, HIVE-23236.3.patch, HIVE-23236.4.patch
>
>
> Currently we have a global lock (NEXT_LOCK_ID) when running enqueueLock, 
> because the algorithm in checkLock requires the locks to have a well defined 
> order, and also requires that every lock component is already stored in the 
> RDBMS before checking the locks.
> Proposed approach:
>  * Enqueue locks without a global S4U lock, using an auto-incremented value 
> instead to get the next lock ID (modify next_lock_id table)
>  * Before checking for lock conflicts, issue a S4U for all lock components we 
> are requesting (db/table/partition level) in order to prevent other clients 
> for doing interleaving conflict check (especially late-coming clients holding 
> a lower lockID)
>  * Conflict check algorithm to check not just for lower lockIDs, but also 
> higher lockIDs which are already in 'acquired' state



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