MDEV-22929 MariaBackup option to report and/or continue when corruption is encountered
The new option --log-innodb-page-corruption is introduced. When this option is set, backup is not interrupted if innodb corrupted page is detected. Instead it logs all found corrupted pages in innodb_corrupted_pages file in backup directory and finishes with error. For incremental backup corrupted pages are also copied to .delta file, because we can't do LSN check for such pages during backup, innodb_corrupted_pages will also be created in incremental backup directory. During --prepare, corrupted pages list is read from the file just after redo log is applied, and each page from the list is checked if it is allocated in it's tablespace or not. If it is not allocated, then it is zeroed out, flushed to the tablespace and removed from the list. If all pages are removed from the list, then --prepare is finished successfully and innodb_corrupted_pages file is removed from backup directory. Otherwise --prepare is finished with error message and innodb_corrupted_pages contains the list of the pages, which are detected as corrupted during backup, and are allocated in their tablespaces, what means backup directory contains corrupted innodb pages, and backup can not be considered as consistent. For incremental --prepare corrupted pages from .delta files are applied to the base backup, innodb_corrupted_pages is read from both base in incremental directories, and the same action is proceded for corrupted pages list as for full --prepare. innodb_corrupted_pages file is modified or removed only in base directory. If DDL happens during backup, it is also processed at the end of backup to have correct tablespace names in innodb_corrupted_pages.
Showing
Please register or sign in to comment