Maintenance
Regular maintenance for Selendra nodes
Regular maintenance ensures optimal node performance and prevents issues. Critical for validators.
Maintenance Schedule
| Task | Frequency | Downtime | Priority |
|---|---|---|---|
| Binary Updates | As released | 2-5 min | High |
| Security Patches | Weekly | 1-10 min | Critical |
| Log Rotation | Automated | None | Medium |
| Database Check | Quarterly | 10-30 min | Low |
| Disk Space | Weekly | None | High |
| Backup Verify | Monthly | None | Medium |
Binary Updates
# Check versions
selendra --version
curl -s https://api.github.com/repos/selendra/selendra/releases/latest | grep "tag_name"
# Update procedure
sudo systemctl stop selendra
sudo cp /usr/local/bin/selendra /usr/local/bin/selendra.backup-$(date +%Y%m%d)
cd /tmp
wget https://github.com/selendra/selendra/releases/latest/download/selendra
chmod +x selendra && ./selendra --version
sudo mv selendra /usr/local/bin/
sudo systemctl start selendra
sudo journalctl -u selendra -f
Validators: Announce updates in Telegram. Stagger updates across hours to maintain network security. Monitor block production after restart.
Notifications: Watch GitHub releases (github.com/selendra/selendra → Watch → Releases).
Security Patches
OS Updates
# Weekly security updates
sudo apt update && sudo apt upgrade -y
sudo reboot # If kernel updated
# Automatic updates (optional)
sudo apt install unattended-upgrades
sudo dpkg-reconfigure -plow unattended-upgrades
Firewall Review
Monthly verification:
sudo ufw status numbered
sudo ss -tulpn | grep LISTEN
Required ports only:
- 30333: P2P (required)
- 9933/9944: RPC (restrict/disable on validators)
- 9615: Metrics (restrict to monitoring system)
Log Management
Rotation Configuration
Create /etc/systemd/journald.conf.d/selendra.conf:
[Journal]
SystemMaxUse=2G
SystemMaxFileSize=200M
MaxRetentionSec=604800
SystemMaxFiles=20
sudo systemctl restart systemd-journald
Log Analysis
# Weekly review
sudo journalctl -u selendra -p err --since "1 week ago"
sudo journalctl -u selendra | grep -i "warn\|peer"
# Archive logs
sudo journalctl -u selendra --since "30 days ago" > selendra-logs-$(date +%Y%m).log
gzip selendra-logs-$(date +%Y%m).log
Database Maintenance
Health Monitoring
# Check size and growth
du -sh /var/lib/selendra/chains/selendra/db
# Verify pruning
sudo journalctl -u selendra | grep -i "pruning"
Clean Shutdowns
Always use: sudo systemctl stop selendra
Never use: kill -9 $(pidof selendra)
Prevention: UPS for power protection, periodic filesystem checks.
Reset After Corruption
sudo systemctl stop selendra
sudo cp -r /var/lib/selendra/chains/selendra/keystore ~/keystore-backup
sudo rm -rf /var/lib/selendra/chains/selendra/db
sudo cp -r ~/keystore-backup /var/lib/selendra/chains/selendra/keystore
sudo systemctl start selendra
Resync time: 4-8 hours.
Disk Space Management
Automated Monitoring
Create /usr/local/bin/check-disk-space.sh:
#!/bin/bash
THRESHOLD=80
USAGE=$(df -h /var/lib/selendra | tail -1 | awk '{print $5}' | sed 's/%//')
if [ $USAGE -gt $THRESHOLD ]; then
echo "Disk usage at ${USAGE}%" | mail -s "Disk Alert" admin@example.com
fi
sudo chmod +x /usr/local/bin/check-disk-space.sh
echo "0 */6 * * * /usr/local/bin/check-disk-space.sh" | sudo crontab -
Expand Storage
Add second drive:
sudo mkfs.ext4 /dev/nvme1n1
sudo mkdir /mnt/selendra-new
sudo systemctl stop selendra
sudo rsync -avP /var/lib/selendra /mnt/selendra-new
# Update base-path in systemd service
sudo systemctl daemon-reload && sudo systemctl start selendra
Resize existing (cloud):
sudo growpart /dev/nvme0n1 1
sudo resize2fs /dev/nvme0n1p1
Free space quickly:
sudo journalctl --vacuum-time=7d
sudo apt clean && sudo apt autoremove -y
Backup Strategies
Validator Keys (Critical)
# Backup and encrypt
sudo tar -czf selendra-keystore-$(date +%Y%m%d).tar.gz \
-C /var/lib/selendra/chains/selendra keystore
gpg -c selendra-keystore-$(date +%Y%m%d).tar.gz
# Store securely: offline USB or encrypted cloud
Test restore annually.
Configuration Backup
mkdir ~/selendra-config-backup
sudo cp /etc/systemd/system/selendra.service ~/selendra-config-backup/
sudo ufw status numbered > ~/selendra-config-backup/firewall-rules.txt
tar -czf selendra-config-$(date +%Y%m%d).tar.gz ~/selendra-config-backup
Database Backup
Not recommended for full nodes (resync faster than restore). For archive nodes:
# Using LVM snapshots
sudo systemctl stop selendra
sudo lvcreate -L 50G -s -n selendra-snapshot /dev/vg/selendra-data
sudo systemctl start selendra
sudo dd if=/dev/vg/selendra-snapshot | gzip > selendra-backup-$(date +%Y%m%d).img.gz &
sudo lvremove /dev/vg/selendra-snapshot
Performance Monitoring
Monthly Review Metrics
| Metric | Optimal | Alert Threshold |
|---|---|---|
| CPU usage | <70% avg | >80% sustained |
| RAM free | >20% | <10% |
| Disk I/O | <80% util | >90% |
| Peers | 25-50 | <5 |
| Block sync | 50-100 blocks/sec | <10 blocks/sec |
Optimization
More cache (if RAM available):
# In systemd service
--state-cache-size 8 # For 32GB+ RAM
Network tuning (validators):
# Add to /etc/sysctl.conf
net.core.rmem_max=26214400
net.core.wmem_max=26214400
net.ipv4.tcp_rmem=4096 87380 16777216
net.ipv4.tcp_wmem=4096 65536 16777216
sudo sysctl -p
Storage: SATA SSD → NVMe = 5-10x improvement.
Disaster Recovery
Recovery Procedures
| Scenario | Steps | Time |
|---|---|---|
| Hardware failure | Restore/rebuild → Sync from network → Restore keys | 4-8 hours |
| Database corruption | Delete DB → Restore keys → Resync | 4-8 hours |
| Key compromise | Rotate session keys immediately → Update on-chain → Investigate | Minutes |
| Network issues | Verify ISP → Test backup connection → Check firewall | Minutes |
Annual Recovery Test
- Setup test node with testnet
- Restore keys from backup
- Start node and verify operation
- Measure recovery time
- Update documentation
Planned Maintenance
Scheduling
Announce: 24-48 hours advance in Telegram
Timing: Weekends, late night/early morning, avoid major events
Coordination: Maintain 2/3 validators online
Checklist
Pre-maintenance:
- Announce in community
- Backup validator keys
- Verify backup restore works
- Document current metrics
During:
- Stop node gracefully
- Perform maintenance
- Verify changes
- Start and monitor
Post-maintenance:
- Verify sync status
- Confirm block production (validators)
- Check peer connectivity
- Review resource usage
Related Documentation
Run Full Node | Run Validator | Monitoring | Troubleshooting
Community
Telegram: t.me/selendranetwork | X: @selendranetwork | GitHub: github.com/selendra/selendra
Coordinate validator maintenance windows in Telegram.
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