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https://issues.apache.org/jira/browse/IMPALA-7501?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Paul Rogers reassigned IMPALA-7501:
-----------------------------------

    Assignee: Paul Rogers

> Slim down metastore Partition objects in LocalCatalog cache
> -----------------------------------------------------------
>
>                 Key: IMPALA-7501
>                 URL: https://issues.apache.org/jira/browse/IMPALA-7501
>             Project: IMPALA
>          Issue Type: Sub-task
>            Reporter: Todd Lipcon
>            Assignee: Paul Rogers
>            Priority: Minor
>
> I took a heap dump of an impalad running in LocalCatalog mode with a 2G limit 
> after running a production workload simulation for a couple hours. It had 
> 38.5M objects and 2.02GB heap (the vast majority of the heap is, as expected, 
> in the LocalCatalog cache). Of this total footprint, 1.78GB and 34.6M objects 
> are retained by 'Partition' objects. Drilling into those, 1.29GB and 33.6M 
> objects are retained by FieldSchema, which, as far as I remember, are ignored 
> on the partition level by the Impala planner. So, with a bit of slimming down 
> of these objects, we could make a huge dent in effective cache capacity given 
> a fixed budget. Reducing object count should also have the effect of improved 
> GC performance (old gen GC is more closely tied to object count than size)



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