After seven weeks of setting up and fine-tuning your PRTG environment, you've created a comprehensive monitoring system. But are your sensors running as efficiently as possible? It's crucial to optimize performance as your monitoring environment grows to ensure accurate data collection without overwhelming your system.
In this final article of our series, we'll explore ways to optimize sensor performance, such as adjusting scanning intervals, implementing dependencies, and following best practices to keep your monitoring system running smoothly.
Although monitoring more devices and parameters provides better visibility into your infrastructure, it also increases the load on your monitoring system. Without proper optimization, you may experience the following:
The key to effective monitoring lies in balancing comprehensive coverage with system performance. Let's explore how you can achieve this balance by making strategic adjustments to your sensor configuration.
This video explains how to adjust scanning intervals in PRTG to optimize your monitoring performance:
One of the most effective ways to optimize sensor performance is to adjust the scanning interval for each monitored device or service based on its criticality to your operations.
A scanning interval is the time between consecutive sensor scans. PRTG offers predefined intervals ranging from 30 seconds to 1 day. While shorter intervals provide more up-to-date information, they also generate more load on your monitoring system and network.
Consider these guidelines when setting scanning intervals:
1️⃣Critical infrastructure (30 seconds - 1 minute)
- Core network switches and routers
- Primary firewalls and security appliances
- Business-critical application servers
- Customer-facing web services
These systems warrant the most frequent checks because any downtime directly impacts operations or customers.
2️⃣ Important systems (2-5 minutes)
- Secondary network equipment
- Internal application servers
These systems are important but can tolerate slightly longer intervals between checks.
3️⃣ Standard systems (10-15 minutes)
- Printers and non-critical network devices
- Development and test systems
- Backup infrastructure
- Internal tools and utilities
For systems where immediate alerting isn't essential, longer intervals reduce system load while still providing useful monitoring.
4️⃣ Long-term trends (30 minutes - 1 hour)
- Capacity planning metrics
- Temperature sensors
- Storage growth monitoring
- Backup job completion
Some metrics change slowly or only need to be checked infrequently. Using longer intervals for these sensors significantly reduces system load.
You can adjust scanning intervals at multiple levels in PRTG:
🧩 Group level: Set default intervals for entire device groups
🧩 Device level: Override group settings for specific devices
🧩 Sensor level: Fine-tune intervals for individual sensors
To change the interval for a specific sensor:
1. Right-click the sensor in the device tree
2. Select Edit | Settings
3. Scroll to the Scanning Interval section
4. Select your desired interval from the dropdown menu
5. Click Save
Check out the following how-to guide for detailed instructions on setting up optimal scanning intervals:
👉 How to set up scanning intervals of sensors in 3 steps
Another powerful way to optimize performance is to set up sensor dependencies. This feature pauses monitoring of dependent sensors when the parent sensor shows a "Down" status. This prevents unnecessary network traffic and reduces system load.
Dependencies are particularly valuable in these scenarios:
🧩 Network hierarchy: If a router is down, there's no need to check devices behind it as they're obviously unreachable.
🧩 Service dependencies: If a database server is down, related application sensors can pause until service is restored.
🧩 Resource monitoring: If a device is offline, there's no need to check its resources like CPU or memory usage.
To configure a dependency, follow these steps:
1. Right-click a sensor that depends on another component
2. Select Edit | Settings
3. Scroll to the Dependencies section
4. Click Add Dependency
5. Select the master object this sensor depends on
6. Click Save
By implementing strategic dependencies, you can significantly reduce unnecessary sensor checks, especially during outages when system resources should be focused on critical monitoring.
Once you've adjusted your scanning intervals and set up basic dependencies, consider these advanced techniques to further optimize performance:
If you're monitoring a large environment with 10,000 or more sensors, consider distributing the load across multiple remote probes. Each probe handles its own monitoring tasks, reducing the burden on your central PRTG server. Remote probes are useful for monitoring geographically distributed locations, balancing sensor-intensive monitoring loads, and reducing WAN traffic by keeping monitoring local.
Auto-discovery is a powerful feature, but it can also generate a significant load. Instead of running continuous discovery, schedule it during off-hours and limit its frequency. Schedule weekly runs for dynamic network segments, monthly runs for stable infrastructure, and quarterly runs for environments that rarely change.
Not all sensors create equal load. When possible, use SNMP instead of WMI, prefer native sensors over custom scripts, and group multiple checks into a single sensor where appropriate. Consider using the Ping sensor to verify availability before running resource-intensive checks on a device.
Periodic maintenance helps keep your PRTG installation running smoothly. Remove unnecessary sensors, adjust intervals as device criticality changes, update to the latest PRTG version, and regularly review historic data settings to optimize storage and performance.
Create a simple document outlining your interval strategy by device and sensor type. This ensures consistency when adding new devices and helps team members understand your approach.
Above all, be willing to adjust your strategy based on real-world experience. If you're receiving too many alerts, try increasing the intervals. Similarly, if you're missing important events, you may need shorter intervals for specific sensors.
Ready to optimize your sensor performance? Here are practical next steps:
📌 Identify your most critical devices and ensure appropriate scanning intervals
📌 Review your largest device groups and adjust intervals based on criticality
📌 Implement dependencies for hierarchical network components
📌 Remove or pause any sensors that aren't providing actionable information
📌 Schedule regular review sessions to continually optimize your monitoring setup
By strategically adjusting scanning intervals and implementing dependencies, you'll create a more efficient monitoring environment that provides timely alerts without overwhelming your system resources.
You've completed our eight-week journey to PRTG mastery!
You discovered devices, moved beyond generic sensors, added specialized sensors, configured notifications, organized with libraries, created dashboards, automated reports, and optimized performance. Your monitoring environment is now well-equipped to keep your infrastructure running smoothly and your team informed.