Implement three critical validation checkpoints to improve recovery reliability
and provide users with clear diagnostic information before recovery attempts.
Issue #1: Pre-flight file validation
- New validate_backup_files() function validates all critical files
before starting MySQL instance (ibdata1, redo logs, mysql/, target DB)
- Checks readability and permissions
- Prevents wasted time starting instance when files are missing
- Provides clear remediation steps if issues found
Issue #2: Enhanced database discovery
- New discover_and_report_databases() function lists all found databases
and explains why target database might be missing
- Automatic system table accessibility testing
- Root cause diagnosis (which system tables are corrupted)
- Actionable remediation suggestions based on failure type
Issue #3: System table validation
- New test_system_tables() function validates critical system tables
after instance starts, before dump attempt
- Tests mysql.db, mysql.innodb_table_stats, information_schema.schemata
- Early detection of system table corruption
- User choice to continue or cancel based on test results
Integration into recovery workflow:
- validate_backup_files() called before instance startup (~line 2080)
- test_system_tables() called after startup, before dump (~line 2184)
- discover_and_report_databases() called in dump_database() (~line 1571)
Benefits:
- Immediate feedback if recovery will fail (before instance startup)
- Clear diagnostic output explaining exactly what's wrong
- No more mystery failures with vague error messages
- Actionable remediation steps for each failure mode
Testing:
- ✓ Syntax validation passed
- ✓ All integration points verified
- ✓ MySQL version compatibility (5.7, 8.0, 8.0.30+)
- ✓ Edge cases handled (permissions, missing tables, corruption)
- ✓ Backward compatible with existing workflow
Related: Ticket #43751550, MYSQL_RESTORE_SCRIPT_IMPROVEMENTS.md
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
cschantz