I can repeat the issue.
Followed the steps in MDEV-31234 in affected version.
1) started the server with --innodb-immediate-scrub-data-uncompressed=1. --innodb_undo_tablespace=0.
2) Ran sysbench. did slow shutdown and ended up with 1528 to_purge undo log pages. (leaked undo log corrupt pages)
Start the latest 10.6 against the data directory, did slow shutdown
2024-07-04 14:29:50 0 [Note] InnoDB: Truncating system tablespace from 4864 to 2496 pages
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2024-07-04 14:29:50 0 [Note] InnoDB: System tablespace truncated successfully
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Ran innochecksum tool against shrinked system tablespace and we end up with same
to_purge Undo page state: 0 active, 128 cached, 1528 to_purge, 0 prepared, 148 other
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So verified what was exist before 2496 page, it was all leaked undo pages and previous extent state has been marked as "XDES_FREE_FRAG" and 12 pages has been used in that extent.
#::2484 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2485 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2486 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2487 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2488 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2489 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2490 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2491 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2492 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2493 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2494 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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#::2495 | Undo log page |, Will be freed in purge when all undodata in it is removed, -
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MDEV-14795 didn't handle leaked undo pages because even their extent has never been marked as freed. So MDEV-14795 assumes that it is used by server.
MDEV-14795 finds the last used extent in the system tablespace and truncates the remaining file.
Attached the ibdata1 of the leaky undo pages for future reference.
Bug
Critical
MDEV-14795 InnoDB system tablespace cannot be shrunk
I can repeat the issue.
Followed the steps in
MDEV-31234in affected version.1) started the server with --innodb-immediate-scrub-data-uncompressed=1. --innodb_undo_tablespace=0.
2) Ran sysbench. did slow shutdown and ended up with 1528 to_purge undo log pages. (leaked undo log corrupt pages)
Start the latest 10.6 against the data directory, did slow shutdown
2024-07-04 14:29:50 0 [Note] InnoDB: Truncating system tablespace from 4864 to 2496 pages2024-07-04 14:29:50 0 [Note] InnoDB: System tablespace truncated successfullyRan innochecksum tool against shrinked system tablespace and we end up with same
to_purge Undo page state: 0 active, 128 cached, 1528 to_purge, 0 prepared, 148 otherSo verified what was exist before 2496 page, it was all leaked undo pages and previous extent state has been marked as "XDES_FREE_FRAG" and 12 pages has been used in that extent.
#::2484 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2485 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2486 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2487 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2488 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2489 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2490 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2491 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2492 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2493 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2494 | Undo log page |, Will be freed in purge when all undodata in it is removed, -#::2495 | Undo log page |, Will be freed in purge when all undodata in it is removed, -MDEV-14795didn't handle leaked undo pages because even their extent has never been marked as freed. SoMDEV-14795assumes that it is used by server.MDEV-14795finds the last used extent in the system tablespace and truncates the remaining file.Attached the ibdata1 of the leaky undo pages for future reference.