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https://issues.apache.org/jira/browse/HIVE-21752?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16879743#comment-16879743
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Jalpan Randeri commented on HIVE-21752:
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No worries, Thank you Alan.
> 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
> Fix For: 4.0.0
>
> Attachments: HIVE-21752.patch, 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]
>
> h4. Review Board Link:
> * [https://reviews.apache.org/r/70674/]
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