LibreNMS Polling & Discovery

Summary

The video explains the critical roles of discovery and polling in LibreNMS, emphasizing how these processes continuously update network device information. It covers the configurations for the poller and discovery scripts, detailing their execution frequency and troubleshooting tips for common issues. Viewers learn to monitor polling performance through various logs and settings, with a focus on optimizing CPU utilization and managing multiple devices. The session provides essential insights for users looking to enhance their network monitoring experience, ensuring efficient data collection and device management.

Takeaways

• 😀 Discovery and polling are central concepts in LibreNMS that allow for real-time data collection and updates from network devices.
• 🕒 The discovery script runs every six hours, while the poller script can be configured to run every minute or five minutes.
• ⚙️ Users can adjust the polling frequency, but it's recommended to configure it correctly from the start to avoid complications later.
• 🔍 The debugging tools in LibreNMS allow users to manually run scripts and view outputs, facilitating troubleshooting of polling issues.
• 📈 Performance metrics such as the number of devices polled and pending devices help monitor the effectiveness of polling operations.
• 💻 Monitoring CPU utilization is crucial when adjusting the number of worker threads to prevent system overload.
• 📜 The polling log provides detailed information on the last poll time and duration for each device, aiding in performance assessment.
• 🚫 For large setups (over 1,000 devices), be cautious with graphical representations of polling data, as they may not capture all devices accurately.
• 🛠️ Future discussions will cover advanced topics like distributed polling and additional modules within LibreNMS.
• ❓ Users are encouraged to leave comments for any questions or clarifications needed regarding the polling and discovery processes.

Q & A

What are the two main concepts discussed in the transcript related to LibreNMS?

The two main concepts are discovery and polling, which are essential for gathering and updating information from network devices.

How often does the polar script run in LibreNMS?

The polar script runs every minute or every five minutes, depending on the configuration set by the user.

What is the purpose of the discovery script?

The discovery script runs every six hours and identifies the operating system and other necessary information needed for the polar script to function effectively.

What can users do if they encounter polling issues with their equipment?

Users can manually run the polar script to check the output and diagnose problems, such as connectivity or SNMP issues.

What happens if the number of pending devices exceeds the capacity of the polling setup?

If there are too many pending devices, users may need to increase the number of worker threads or implement distributed polling by adding another polar.

What are worker threads, and why are they important in polling?

Worker threads are processes that handle polling tasks. The number of threads impacts performance and CPU utilization; too many concurrent tasks can overload the system.

What must be done after changing the settings for the polar script in LibreNMS?

After changing the settings, the LibreNMS service must be restarted for the changes to take effect, and updates will be reflected in the next polling interval.

How can users monitor the performance of their polling processes?

Users can check the polar statistics through the gear icon to see how many devices were actioned and if any are pending, helping them gauge performance.

What troubleshooting tools are mentioned for ensuring effective polling?

The polar log and performance graphs are useful tools for tracking the last polling time of devices and identifying which devices may be taking longer than expected.

What caution should users take when monitoring polling times with a large number of devices?

With a very large setup (e.g., over 1,000 devices), the polling time graphs may become unreliable, as they may not accurately represent the performance due to data collection limitations.