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https://issues.apache.org/jira/browse/HIVE-9741?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Xiaobing Zhou updated HIVE-9741:
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Description:
MetaStoreDirectSql constructor is querying DB to determine dbType, which leads
to too many DB queries to make megastore slow as ObjectStore.setConf might be
called frequently. Moreover, ObjectStore.setConf begins/ends with lock
acquire/release, if the underlying DB hangs somehow, lock is never released and
all hereafter incoming requests are blocked.
This is to propose using getProductName to get dbType info.
Here’s stack trace:
MetaStoreDirectSql.determineDbType(...)
MetaStoreDirectSql.MetaStoreDirectSql(...)
ObjectStore.initialize(...)
ObjectStore.setConf(…)
was:MetaStoreDirectSql constructor is querying DB to determine dbType. which
leads to too many DB queries to make metastore slow or hanging if
MetaStoreDirectSql constructor is frequently called. This is to propose
getProductName to get dbType info.
> Refactor MetaStoreDirectSql constructor
> ----------------------------------------
>
> Key: HIVE-9741
> URL: https://issues.apache.org/jira/browse/HIVE-9741
> Project: Hive
> Issue Type: Bug
> Components: Metastore
> Affects Versions: 1.0.0
> Reporter: Xiaobing Zhou
> Assignee: Xiaobing Zhou
> Attachments: HIVE-9741.1.patch, HIVE-9741.2.patch
>
>
> MetaStoreDirectSql constructor is querying DB to determine dbType, which
> leads to too many DB queries to make megastore slow as ObjectStore.setConf
> might be called frequently. Moreover, ObjectStore.setConf begins/ends with
> lock acquire/release, if the underlying DB hangs somehow, lock is never
> released and all hereafter incoming requests are blocked.
> This is to propose using getProductName to get dbType info.
> Here’s stack trace:
> MetaStoreDirectSql.determineDbType(...)
> MetaStoreDirectSql.MetaStoreDirectSql(...)
> ObjectStore.initialize(...)
> ObjectStore.setConf(…)
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