feat: Week 3 Phase 5 - PITR Tests & Documentation

- Created comprehensive test suite (700+ lines)
  * 7 major test functions with 21+ sub-tests
  * Recovery target validation (time/XID/LSN/name/immediate)
  * WAL archiving (plain, compressed, with mock files)
  * WAL parsing (filename validation, error cases)
  * Timeline management (history parsing, consistency, path finding)
  * Recovery config generation (PG 12+ and legacy formats)
  * Data directory validation (exists, writable, not running)
  * Performance benchmarks (WAL archiving, target parsing)
  * All tests passing (0.031s execution time)

- Updated README.md with PITR documentation (200+ lines)
  * Complete PITR overview and benefits
  * Step-by-step setup guide (enable, backup, monitor)
  * 5 recovery target examples with full commands
  * Advanced options (compression, encryption, actions, timelines)
  * Complete WAL management command reference
  * 7 best practices recommendations
  * Troubleshooting section with common issues

- Created PITR.md standalone guide
  * Comprehensive PITR documentation
  * Use cases and practical examples
  * Setup instructions with alternatives
  * Recovery operations for all target types
  * Advanced features (compression, encryption, timelines)
  * Troubleshooting with debugging tips
  * Best practices and compliance guidance
  * Performance considerations

- Updated CHANGELOG.md with v3.1 PITR features
  * Complete feature list (WAL archiving, timeline mgmt, recovery)
  * New commands (pitr enable/disable/status, wal archive/list/cleanup/timeline)
  * PITR restore with all target types
  * Advanced features and configuration examples
  * Technical implementation details
  * Performance metrics and use cases

Phases completed:
- Phase 1: WAL Archiving (1.5h) ✓
- Phase 2: Compression & Encryption (1h) ✓
- Phase 3: Timeline Management (0.75h) ✓
- Phase 4: Point-in-Time Restore (1.25h) ✓
- Phase 5: Tests & Documentation (1.25h) ✓

All PITR functionality implemented, tested, and documented.
This commit is contained in:
2025-11-26 12:21:46 +00:00
parent 778afc16d9
commit 456e128ec4
4 changed files with 1687 additions and 0 deletions

236
README.md
View File

@@ -691,6 +691,242 @@ Display version information:
./dbbackup version
```
## Point-in-Time Recovery (PITR)
dbbackup v3.1 includes full Point-in-Time Recovery support for PostgreSQL, allowing you to restore your database to any specific moment in time, not just to the time of your last backup.
### PITR Overview
Point-in-Time Recovery works by combining:
1. **Base Backup** - A full database backup
2. **WAL Archives** - Continuous archive of Write-Ahead Log files
3. **Recovery Target** - The specific point in time you want to restore to
This allows you to:
- Recover from accidental data deletion or corruption
- Restore to a specific transaction or timestamp
- Create multiple recovery branches (timelines)
- Test "what-if" scenarios by restoring to different points
### Enable PITR
**Step 1: Enable WAL Archiving**
```bash
# Configure PostgreSQL for PITR
./dbbackup pitr enable --archive-dir /backups/wal_archive
# This will modify postgresql.conf:
# wal_level = replica
# archive_mode = on
# archive_command = 'dbbackup wal archive %p %f ...'
# Restart PostgreSQL for changes to take effect
sudo systemctl restart postgresql
```
**Step 2: Take a Base Backup**
```bash
# Create a base backup (use pg_basebackup or dbbackup)
pg_basebackup -D /backups/base_backup.tar.gz -Ft -z -P
# Or use regular dbbackup backup with --pitr flag (future feature)
./dbbackup backup single mydb --output /backups/base_backup.tar.gz
```
**Step 3: Continuous WAL Archiving**
WAL files are now automatically archived by PostgreSQL to your archive directory. Monitor with:
```bash
# Check PITR status
./dbbackup pitr status
# List archived WAL files
./dbbackup wal list --archive-dir /backups/wal_archive
# View timeline history
./dbbackup wal timeline --archive-dir /backups/wal_archive
```
### Perform Point-in-Time Recovery
**Restore to Specific Timestamp:**
```bash
./dbbackup restore pitr \
--base-backup /backups/base_backup.tar.gz \
--wal-archive /backups/wal_archive \
--target-time "2024-11-26 12:00:00" \
--target-dir /var/lib/postgresql/14/restored \
--target-action promote
```
**Restore to Transaction ID (XID):**
```bash
./dbbackup restore pitr \
--base-backup /backups/base_backup.tar.gz \
--wal-archive /backups/wal_archive \
--target-xid 1000000 \
--target-dir /var/lib/postgresql/14/restored
```
**Restore to Log Sequence Number (LSN):**
```bash
./dbbackup restore pitr \
--base-backup /backups/base_backup.tar.gz \
--wal-archive /backups/wal_archive \
--target-lsn "0/3000000" \
--target-dir /var/lib/postgresql/14/restored
```
**Restore to Named Restore Point:**
```bash
# First create a restore point in PostgreSQL:
psql -c "SELECT pg_create_restore_point('before_migration');"
# Later, restore to that point:
./dbbackup restore pitr \
--base-backup /backups/base_backup.tar.gz \
--wal-archive /backups/wal_archive \
--target-name before_migration \
--target-dir /var/lib/postgresql/14/restored
```
**Restore to Earliest Consistent Point:**
```bash
./dbbackup restore pitr \
--base-backup /backups/base_backup.tar.gz \
--wal-archive /backups/wal_archive \
--target-immediate \
--target-dir /var/lib/postgresql/14/restored
```
### Advanced PITR Options
**WAL Compression and Encryption:**
```bash
# Enable compression for WAL archives (saves space)
./dbbackup pitr enable \
--archive-dir /backups/wal_archive
# Archive with compression
./dbbackup wal archive /path/to/wal %f \
--archive-dir /backups/wal_archive \
--compress
# Archive with encryption
./dbbackup wal archive /path/to/wal %f \
--archive-dir /backups/wal_archive \
--encrypt \
--encryption-key-file /secure/key.bin
```
**Recovery Actions:**
```bash
# Promote to primary after recovery (default)
--target-action promote
# Pause recovery at target (for inspection)
--target-action pause
# Shutdown after recovery
--target-action shutdown
```
**Timeline Management:**
```bash
# Follow specific timeline
--timeline 2
# Follow latest timeline (default)
--timeline latest
# View timeline branching structure
./dbbackup wal timeline --archive-dir /backups/wal_archive
```
**Auto-start and Monitor:**
```bash
# Automatically start PostgreSQL after setup
./dbbackup restore pitr \
--base-backup /backups/base_backup.tar.gz \
--wal-archive /backups/wal_archive \
--target-time "2024-11-26 12:00:00" \
--target-dir /var/lib/postgresql/14/restored \
--auto-start \
--monitor
```
### WAL Management Commands
```bash
# Archive a WAL file manually (normally called by PostgreSQL)
./dbbackup wal archive <wal_path> <wal_filename> \
--archive-dir /backups/wal_archive
# List all archived WAL files
./dbbackup wal list --archive-dir /backups/wal_archive
# Clean up old WAL archives (retention policy)
./dbbackup wal cleanup \
--archive-dir /backups/wal_archive \
--retention-days 7
# View timeline history and branching
./dbbackup wal timeline --archive-dir /backups/wal_archive
# Check PITR configuration status
./dbbackup pitr status
# Disable PITR
./dbbackup pitr disable
```
### PITR Best Practices
1. **Regular Base Backups**: Take base backups regularly (daily/weekly) to limit WAL archive size
2. **Monitor WAL Archive Space**: WAL files can accumulate quickly, monitor disk usage
3. **Test Recovery**: Regularly test PITR recovery to verify your backup strategy
4. **Retention Policy**: Set appropriate retention with `wal cleanup --retention-days`
5. **Compress WAL Files**: Use `--compress` to save storage space (3-5x reduction)
6. **Encrypt Sensitive Data**: Use `--encrypt` for compliance requirements
7. **Document Restore Points**: Create named restore points before major changes
### Troubleshooting PITR
**Issue: WAL archiving not working**
```bash
# Check PITR status
./dbbackup pitr status
# Verify PostgreSQL configuration
grep -E "archive_mode|wal_level|archive_command" /etc/postgresql/*/main/postgresql.conf
# Check PostgreSQL logs
tail -f /var/log/postgresql/postgresql-14-main.log
```
**Issue: Recovery target not reached**
```bash
# Verify WAL files are available
./dbbackup wal list --archive-dir /backups/wal_archive
# Check timeline consistency
./dbbackup wal timeline --archive-dir /backups/wal_archive
# Review PostgreSQL recovery logs
tail -f /var/lib/postgresql/14/restored/logfile
```
**Issue: Permission denied during recovery**
```bash
# Ensure data directory ownership
sudo chown -R postgres:postgres /var/lib/postgresql/14/restored
# Verify WAL archive permissions
ls -la /backups/wal_archive
```
For more details, see [PITR.md](PITR.md) documentation.
## Cloud Storage Integration
dbbackup v2.0 includes native support for cloud storage providers. See [CLOUD.md](CLOUD.md) for complete documentation.