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https://issues.apache.org/jira/browse/HIVE-21752?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jalpan Randeri updated HIVE-21752:
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    Attachment: HIVE-21752.patch

> Thread Safety and Memory Leaks in HCatRecordObjectInspectorFactory
> ------------------------------------------------------------------
>
>                 Key: HIVE-21752
>                 URL: https://issues.apache.org/jira/browse/HIVE-21752
>             Project: Hive
>          Issue Type: Bug
>          Components: HCatalog
>            Reporter: Jalpan Randeri
>            Assignee: Jalpan Randeri
>            Priority: Minor
>              Labels: newbie, patch
>         Attachments: HIVE-21752.patch
>
>   Original Estimate: 24h
>  Remaining Estimate: 24h
>
> h3. Summary
> There are a couple of issues in HCatRecordObjectInspectorFactory[1] because 
> it uses a static Java HashMap to cache objects:
>  # Java HashMap is not thread safe. This can lead to data corruptions and 
> race conditions in multithreaded servers when two threads update the 
> ObjectInspector.
>  # There is no eviction policy and as a result, this can result in memory 
> leaks. If user reads a lot of different schemas, Hive server will start 
> seeing memory pressure, once it start going to have a lot of cached record 
> and object inspectors.
> This patch propose to replace the cache using a Guava cache which enables 
> cache evictions and thread safety. Guava cache is already used in Hive 
> ObjectInspectorFactory [2], so this change is consistent with the rest of 
> Hive.
> Attached is a patch that fixes this issue.
> h3. References:
>  # 
> https://github.com/apache/hive/blob/b58d50cb73a1f79a5d079e0a2c5ac33d2efc33a0/hcatalog/core/src/main/java/org/apache/hive/hcatalog/data/HCatRecordObjectInspectorFactory.java#L44-L47
>  # 
> https://github.com/apache/hive/blob/b58d50cb73a1f79a5d079e0a2c5ac33d2efc33a0/serde/src/java/org/apache/hadoop/hive/serde2/objectinspector/ObjectInspectorFactory.java#L68-L87



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