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https://issues.apache.org/jira/browse/IMPALA-15258?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Michael Smith resolved IMPALA-15258.
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Fix Version/s: Impala 5.0.0
Resolution: Fixed
> Query can hang in BufferPool::Client::CleanPages
> ------------------------------------------------
>
> Key: IMPALA-15258
> URL: https://issues.apache.org/jira/browse/IMPALA-15258
> Project: IMPALA
> Issue Type: Bug
> Components: Backend
> Affects Versions: Impala 4.5.0
> Reporter: Michael Smith
> Assignee: Michael Smith
> Priority: Major
> Fix For: Impala 5.0.0
>
>
> With plans produced with CTEs by IMPALA-13533, I've observed the query
> hanging during BufferPool CleanPages. Stack traces showed a thread waiting on
> [https://github.com/apache/impala/blob/master/be/src/runtime/bufferpool/buffer-pool.cc#L713.|https://github.com/apache/impala/blob/master/be/src/runtime/bufferpool/buffer-pool.cc#L713]
> Further logging showed a scenario where {{target_dirty_bytes}} is negative:
> {code:java}
> I20260812 22:48:09.199885 141206 buffer-pool.cc:679]
> 254fc219ed384ebf:227b64f700000010] target_dirty_bytes=-1048576
> reservation=17825792 buffers_allocated_bytes_=1048576 pinned_pages_.bytes()=0
> len=17825792 {code}
> I noticed that {{buffers_allocated_bytes_}} is usually guarded by
> {{{}lock_{}}}, but in
> [DestroyPageInternal|https://github.com/apache/impala/blob/master/be/src/runtime/bufferpool/buffer-pool.cc#L493]
> it's not. Moving that update into the lock seems to fix the hang.
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