Compression

Reduce backup file sizes with Gzip or Brotli compression.

Overview

Compression significantly reduces:

• Storage costs - Smaller files = less storage
• Transfer time - Less data to upload
• Network bandwidth - Lower bandwidth usage

Typical compression ratios for SQL dumps:

Content Type	Compression Ratio
SQL dumps (text)	60-80% smaller
Binary data (BLOBs)	10-30% smaller
Already compressed	0-5% smaller

Compression Algorithms

Gzip

Best for: General use, fast compression

Aspect	Rating
Speed	⭐⭐⭐⭐⭐ Fast
Compression	⭐⭐⭐ Good
CPU Usage	Low
Compatibility	Universal

Brotli

Best for: Maximum compression, slower systems acceptable

Aspect	Rating
Speed	⭐⭐⭐ Moderate
Compression	⭐⭐⭐⭐⭐ Excellent
CPU Usage	Medium
Compatibility	Modern

Comparison

100MB SQL dump:

Algorithm	Compressed Size	Time
None	100 MB	0s
Gzip	25 MB (75% reduction)	~5s
Brotli	20 MB (80% reduction)	~15s

Enabling Compression

On Job Creation

1. Create or edit a backup job
2. In Processing section, enable Compression
3. Select algorithm: Gzip or Brotli
4. Save

File Extensions

Compressed backups have extensions:

• Gzip: backup.sql.gz
• Brotli: backup.sql.br

With encryption:

• backup.sql.gz.enc
• backup.sql.br.enc

Pipeline Order

Compression happens before encryption:

Database → Dump → Compress → Encrypt → Upload
                     ↑          ↑
                   Gzip/Brotli  AES-256

This order is optimal because:

1. Encrypted data doesn't compress well
2. Compression works best on text data
3. Smaller encrypted file to upload

Streaming Architecture

DBackup uses streaming compression:

dumpStream
  .pipe(compressionStream)
  .pipe(encryptionStream)
  .pipe(uploadStream)

Benefits:

• Low memory: Doesn't load entire file
• Fast: Parallel processing
• Scalable: Works with any size database

When to Use

Use Gzip When

• Backup speed is critical
• CPU resources are limited
• Compatibility is important
• Good balance needed

Use Brotli When

• Storage costs are high
• Maximum compression wanted
• Time is not critical
• Modern systems only

Skip Compression When

• Database contains mostly binary BLOBs
• Network is faster than compression time
• Immediate backups needed

Storage Savings

Example: 1GB Database

Setup	Size	Monthly Cost*
No compression	30 GB (30 daily)	$0.69
Gzip	7.5 GB	$0.17
Brotli	6 GB	$0.14

*S3 Standard pricing ($0.023/GB)

Yearly Savings

For 10 databases with Smart retention:

• No compression: ~300 GB = $83/year
• With Gzip: ~75 GB = $21/year
• Savings: $62/year per 10 databases

Restore and Download

Automatic Decompression

When restoring or downloading:

1. DBackup reads metadata
2. Detects compression algorithm
3. Decompresses automatically

Manual Decompression

If needed outside DBackup:

# Gzip
gunzip backup.sql.gz

# Brotli
brotli -d backup.sql.br

Performance Tuning

CPU Considerations

Compression uses CPU. Monitor during backups:

• High CPU: Consider Gzip over Brotli
• Multiple jobs: Stagger schedules

Memory Usage

Streaming keeps memory low, but:

• Brotli uses more memory than Gzip
• Large databases may need more resources

Disk I/O

Compression reduces disk writes:

• Smaller temp files
• Faster uploads
• Less disk wear

Metadata Storage

Compression info stored in .meta.json:

{
  "compression": "GZIP",
  "encryption": {
    "enabled": false
  },
  "originalSize": 104857600,
  "compressedSize": 26214400
}

Troubleshooting

Compression Slow

Causes:

• Large database
• Brotli algorithm
• CPU constraints

Solutions:

1. Switch to Gzip
2. Schedule during low-usage
3. Check CPU availability

Decompression Fails

Causes:

• Corrupted file
• Wrong algorithm detected
• Incomplete download

Solutions:

1. Re-download from storage
2. Check .meta.json for correct algorithm
3. Verify file integrity

File Larger After Compression

Cause: Already compressed data (images, PDFs)

Solution:

1. Consider skipping compression
2. Or accept minimal overhead

Best Practices

1. Start with Gzip - Good balance for most cases
2. Monitor backup times - Switch if too slow
3. Compare sizes - Test both algorithms
4. Enable for all jobs - Storage savings add up
5. Combine with encryption - Compress then encrypt
6. Test restores - Verify decompression works

Next Steps

• Encryption - Encrypt compressed backups
• Creating Jobs - Configure compression
• Storage Explorer - View backup sizes