2.8 KiB
Performance Tuning
Symptom-First Triage
| Symptom | First checks | Likely next action |
|---|---|---|
| Throughput lower than expected | queue/CPU distribution, integration strategy depth, scheduler health | reduce hierarchy depth or use promote_to_root, then retest |
| High CPU on one core | IRQ/queue imbalance, root-node bottlenecks | rebalance queue/IRQ affinity and/or promote heavy remote sites to root |
| Performance changed after integration edits | strategy and topology depth changed unintentionally | confirm strategy (flat/ap_only/ap_site/full) and validate tree/flow shape |
CPU and IRQ Baseline
Set CPU frequency governor to performance on bare metal/hypervisor hosts:
sudo cpupower frequency-set --governor performance
Confirm NIC queue count and CPU distribution are sensible for your hardware:
ethtool -l <interface>
grep -E 'CPU\\(|IRQ' /proc/interrupts | head -n 50
If a single queue/CPU is saturated while others are idle, rebalance queue/IRQ affinity and revisit queue-count settings in /etc/lqos.conf.
Topology/Queue Pressure
When shaping large hierarchies:
- Prefer lower-depth integration strategies (
ap_only/ap_site) unless full hierarchy is required. - Use
promote_to_rootfor large multi-site topologies to avoid single-core choke points. - Validate WebUI CPU Tree/CPU Weights after major topology changes.
Scheduler Refresh and Load
lqos_scheduler refresh cadence affects control-plane load and change responsiveness.
- Start with a conservative
queue_refresh_interval_mins. - Decrease interval only if your integration/API and host can handle the extra churn.
- After changing interval, monitor:
journalctl -u lqos_scheduler --since "30 minutes ago"- WebUI scheduler status
StormGuard Rollout
If using StormGuard:
- Start with
dry_run = true. - Observe at least one busy period.
- Move to live mode only after reviewing debug/status behavior.
See StormGuard for details.
Startup/Boot Delays
If Ubuntu startup is slow due to network-online dependencies, inspect target dependencies:
systemctl show -p WantedBy network-online.target
On some Ubuntu installs, disabling unused cloud/iSCSI services may help:
sudo systemctl disable cloud-config iscsid cloud-final
Validate this against your environment before disabling services.
Routing Convergence (OSPF)
For routed deployments, tune OSPF neighbor timers on core and edge routers to reduce outage windows during reboots:
- hello interval
- dead interval