[MCOL-5102] mcsRebuildEM - Triage - Failed to open compressed data file Created: 2022-05-25  Updated: 2023-11-17  Resolved: 2022-08-10

Status: Closed
Project: MariaDB ColumnStore
Component/s: None
Affects Version/s: 6.2.2
Fix Version/s: 22.08.1

Type: Bug Priority: Minor
Reporter: Allen Herrera Assignee: Denis Khalikov
Resolution: Fixed Votes: 0
Labels: None

Attachments: Zip Archive FILE002.cdf_140.zip     PNG File RebuildEMoutput.png     PNG File checkFileSystem.png    
Issue Links:
Relates
relates to MCOL-4819 Request for improved recovery options Open
Sprint: 2021-17
Assigned for Review: Roman Roman
Assigned for Testing: Daniel Lee Daniel Lee (Inactive)

 Description   

Background
Continuing from slack: https://mariadb.slack.com/archives/C03G6V1RH1D/p1653333586247559

I tried using mcsRebuildEM with a client on prem because of their existing extent map not working nor their backups. Roman has some details on why the existing map didnt work, something about OID 1001 and only 79 bytes existing when 80 expected. In the end we had to wipe all their columnstore data and reinstall columnstore and re-import their data to get them back online which is not acceptable or even possible sometimes.

Ask
1) Whats wrong with `/var/lib/columnstore/data3/old_3/000.dir/010.dir/140.dir/014.dir/000.dir/FILE002.cdf`
2) why couldnt mcsRebuildEM open the file
3) what are some possible reasons the client environment / files get in this state ( guesses ok )

Files
See attachments

 Comments   
Comment by Daniel Lee (Inactive) [ 2022-08-10 ]

Build verified: 22.08-1 (#5243)

Verified by repeated the same with a 100gb dbt3 database on a 3-node docker cluster.

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