llnl / llnl/Privateer

Failed compression/decompression for specific region size (during page eviction ranges)

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Dominant language
C++
Stars
5
Forks
6
PR merge metrics
No merged PRs in 30d

Description

When running the tests with zstd compression enabled, it appears that compression/decompression fails when running the tests:

Immutable
SimpleWrite
SimpleDenseWrite
SimpleWrite_Data
SortWrite
MultipleWrite

With the exception of SimpleWrite and Immutable (these test writes to 4 sparse locations in the datastore region), the other four tests write to the entirety of the datastore region. These tests fail when specifically running with a datastore size of 8MB and max block number of 1 and 2 (page eviction occurs due to cache size < region size).

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  3. Fork the repository and make your change on a branch.
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Research direction

Start by reproducing the failure with zstd enabled in Immutable, SimpleWrite, SimpleDenseWrite, SimpleWrite_Data, SortWrite, and MultipleWrite. Compare the failing 8MB datastore cases with max block numbers 1 and 2, where page eviction occurs because the cache is smaller than the region. Done means compression and decompression succeed for the affected tests.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
databases, performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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