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https://issues.apache.org/jira/browse/IMPALA-14082?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Quanlong Huang updated IMPALA-14082:
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    Description: 
Currently, only ALTER_PARTITION and INSERT partition events are processed in 
batches. RELOAD events are triggered by REFRESH in other Impala clusters. There 
could be lots of partition level REFRESH on the same table. Processing them one 
by one acquires the table lock multiple times to load individual partitions in 
sequence. This also keeps the table version changing which impacts performance 
of coordinators in local-catalog mode - query planning needs retry to handle 
InconsistentMetadataFetchException due to table version changes.

Batch processing RELOAD events on the same table can load partiitons in 
parallel and also reduce duplicate reloads.

CC [~hemanth619], [~VenuReddy] 

  was:
Currently, only ALTER_PARTITION and INSERT partition events are processed in 
batches. RELOAD events are triggered by REFRESH in other Impala clusters. There 
could be lots of partition level REFRESH on the same table. Processing them one 
by one keeps the table version changing and acquires the table lock multiple 
times to load individual partitions in sequence. Batch processing RELOAD events 
on the same table can load partiitons in parallel and reduce duplicate reloads.

CC [~hemanth619], [~VenuReddy] 


> Batch processing RELOAD events on the same table
> ------------------------------------------------
>
>                 Key: IMPALA-14082
>                 URL: https://issues.apache.org/jira/browse/IMPALA-14082
>             Project: IMPALA
>          Issue Type: Improvement
>          Components: Catalog
>            Reporter: Quanlong Huang
>            Priority: Major
>
> Currently, only ALTER_PARTITION and INSERT partition events are processed in 
> batches. RELOAD events are triggered by REFRESH in other Impala clusters. 
> There could be lots of partition level REFRESH on the same table. Processing 
> them one by one acquires the table lock multiple times to load individual 
> partitions in sequence. This also keeps the table version changing which 
> impacts performance of coordinators in local-catalog mode - query planning 
> needs retry to handle InconsistentMetadataFetchException due to table version 
> changes.
> Batch processing RELOAD events on the same table can load partiitons in 
> parallel and also reduce duplicate reloads.
> CC [~hemanth619], [~VenuReddy] 



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