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🌐 LibreNMS Data Source Configuration

Connecting Network Device Monitoring to Grafana

Module Overview

In this module, you'll configure Grafana to connect to the LibreNMS MySQL database, enabling visualization of SNMP-based network device metrics including interface traffic, device availability, BGP session status, and environmental sensors.

🏗️ Understanding the LibreNMS Data Model

LibreNMS stores all collected metrics in a MySQL/MariaDB database. Understanding the schema is critical for writing effective queries. The database uses a relational model where devices are the central entity, with related tables storing ports, sensors, BGP peers, and historical metrics.

Step 1: Core Database Tables

LibreNMS organizes data across several key tables. Here are the most important ones for dashboard creation:

Table Name Purpose Key Columns
devices Network devices inventory device_id, hostname, sysName, location, status, uptime
ports Network interfaces and statistics port_id, device_id, ifName, ifAlias, ifSpeed, ifOperStatus
bgpPeers BGP neighbor relationships bgpPeer_id, device_id, bgpPeerRemoteAddr, bgpPeerState
sensors Environmental and hardware sensors sensor_id, device_id, sensor_class, sensor_current, sensor_limit
bill_port_counters 95th percentile billing data bill_id, timestamp, in_delta, out_delta
eventlog Device and interface events event_id, device_id, type, message, datetime

Pro Tip: Table Relationships

Almost all queries will join back to the devices table using device_id as the foreign key. This allows you to filter by hostname, location, or device attributes while retrieving port or sensor data. The ports table is your primary source for interface bandwidth metrics.

  • LibreNMS database schema overview
  • Key tables: devices, ports, bgpPeers, sensors
  • Pre-calculated rates vs raw SNMP data
  • Timestamp formats and polling intervals

    • Content to add: Database diagram, table relationships, example queries showing data structure

    🔐 Section 2: Creating Read-Only Database User

    • Why use dedicated read-only credentials
    • MySQL user creation commands
    • Granting SELECT permissions
    • Testing database connectivity
    # Placeholder for MySQL commands CREATE USER 'grafana_readonly'@'%' IDENTIFIED BY 'SecurePassword'; GRANT SELECT ON librenms.* TO 'grafana_readonly'@'%'; FLUSH PRIVILEGES;

    ⚙️ Section 3: Adding MySQL Data Source in Grafana

    • Navigate to Data Sources configuration
    • Select MySQL data source type
    • Configure connection parameters (host, port, database, credentials)
    • Set connection pooling options
    • Test connection and troubleshoot

    Content to add: Screenshots of Grafana UI, step-by-step configuration walkthrough

    📊 Section 4: Writing Your First LibreNMS Query

    • Query device inventory
    • Retrieve interface statistics
    • Calculate bandwidth utilization
    • Time-based filtering with $__timeFilter()
    • Using Grafana variables in queries
    -- Example: Interface traffic query SELECT UNIX_TIMESTAMP(datetime) as time_sec, ifInOctets_rate * 8 / 1000000 as value, CONCAT(hostname, ' - ', ifName) as metric FROM ports INNER JOIN devices ON ports.device_id = devices.device_id WHERE $__timeFilter(datetime) ORDER BY datetime

    🎨 Section 5: Creating Dashboard Variables

    • Device selection variable (query: SELECT DISTINCT hostname FROM devices)
    • Interface selection variable
    • Multi-value and "All" options
    • Variable dependency and chaining

    📈 Section 6: Building Network Monitoring Panels

    • Panel 1: Device availability status (Stat panel)
    • Panel 2: Interface bandwidth time series
    • Panel 3: BGP peer status table
    • Panel 4: Top interfaces by utilization
    • Panel 5: Device error rates

    Content to add: Complete SQL queries for each panel, panel configuration options, expected output examples

    🔧 Section 7: Common LibreNMS Query Patterns

    • Joining devices and ports tables
    • Aggregating data across multiple interfaces
    • Calculating percentages and ratios
    • Handling NULL values and missing data
    • Performance optimization tips

    ✅ Section 8: Verification and Testing

    • Verify data source shows green status
    • Test queries return expected results
    • Compare values with LibreNMS UI
    • Check query performance (execution time)
    • Validate timestamp accuracy

    🎯 Expansion Guidelines

    When expanding this module, include:

    • Step-by-step screenshots of Grafana UI
    • Complete, tested SQL queries with explanations
    • Common error messages and solutions
    • Real-world examples from production environments
    • Security best practices and warnings
    • Performance benchmarks and optimization tips
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