Kernel and DuckDB Integration

Input and output integration overview

The Kernel plugin collects various statistics about the Linux kernel, including context switches, page usage, and entropy availability.

This plugin enables Telegraf to write structured metrics into DuckDB using SQLite-compatible SQL connections, supporting lightweight local analytics and offline metric analysis.

Integration details

Kernel

The Kernel plugin is designed exclusively for Linux systems and gathers essential kernel statistics that are not covered by other plugins. It primarily focuses on the metrics available in /proc/stat, as well as the entropy available from /proc/sys/kernel/random/entropy_avail. Additional functionalities include the capture of Kernel Samepage Merging (KSM) data and Pressure Stall Information (PSI), requiring Linux kernel version 4.20 or later. This plugin provides a comprehensive look into system behaviors, enabling better understanding and optimization of resource management and usage. The metrics it collects are critical for monitoring system health and performance.

DuckDB

Use the Telegraf SQL plugin to write metrics into a local DuckDB database. DuckDB is an in-process OLAP database designed for efficient analytical queries on columnar data. Although it does not provide a traditional client-server interface, DuckDB can be accessed via SQLite-compatible drivers in embedded mode. This allows Telegraf to store time series metrics in DuckDB using SQL, enabling powerful analytics workflows using familiar SQL syntax, Jupyter notebooks, or integration with data science tools like Python and R. DuckDB’s columnar storage and vectorized execution make it ideal for compact and high-performance metric archives.

Configuration

Kernel

[[inputs.kernel]]
  ## Additional gather options
  ## Possible options include:
  ## * ksm - kernel same-page merging
  ## * psi - pressure stall information
  # collect = []

DuckDB

[[outputs.sql]]
  ## Use the SQLite driver to connect to DuckDB via Go's database/sql
  driver = "sqlite3"

  ## DSN should point to the DuckDB database file
  dsn = "file:/var/lib/telegraf/metrics.duckdb"

  ## SQL INSERT statement with placeholders for metrics
  table_template = "INSERT INTO metrics (timestamp, name, value, tags) VALUES (?, ?, ?, ?)"

  ## Optional: manage connection pooling
  # max_open_connections = 1
  # max_idle_connections = 1
  # conn_max_lifetime = "0s"

  ## DuckDB does not require TLS or authentication by default

Input and output integration examples

Kernel

1. Memory Optimization through KSM: Utilize the KSM capabilities of this plugin to monitor memory usage patterns in your applications and dynamically adjust the memory allocation strategy based on shared page usage metrics. By analyzing the data collected, you can identify opportunities for consolidating memory and optimizing performance without manual intervention.

2. Real-time System Health Monitoring: Integrate the metrics collected by the Kernel plugin into a real-time dashboard that visualizes key kernel statistics including context switches, interrupts, and entropy availability. This setup allows system administrators to proactively respond to performance issues before they escalate into critical failures, ensuring smooth operation of Linux servers.

3. Enhanced Anomaly Detection: Combine the data from this plugin with machine learning models to predict and detect anomalies in kernel behavior. By continuously monitoring metrics like process forking rates and entropy levels, you can implement an adaptive alerting system that triggers on performance anomalies, allowing for quick responses to potential issues.

4. Resource Usage Patterns Analysis: Use the Pressure Stall Information collected by the plugin to analyze resource usage patterns over time and identify potential bottlenecks under load conditions. By adjusting application performance based on the PSI metrics, you can improve overall resource management and maintain service reliability under varying workloads.

DuckDB

1. Embedded Metric Warehousing for Notebooks: Write metrics to a local DuckDB file from Telegraf and analyze them in Jupyter notebooks using Python or R. This workflow supports reproducible analytics, ideal for data science experiments or offline troubleshooting.

2. Batch Time-Series Processing on the Edge: Use Telegraf with DuckDB on edge devices to log metrics locally in SQL format. The compact storage and fast analytical capabilities of DuckDB make it ideal for batch processing and low-bandwidth environments.

3. Exploratory Querying of Historical Metrics: Accumulate system metrics over time in DuckDB and perform exploratory data analysis (EDA) using SQL joins, window functions, and aggregates. This enables insights that go beyond what typical time-series dashboards provide.

4. Self-Contained Metric Snapshots: Use DuckDB as a portable metrics archive by shipping .duckdb files between systems. Telegraf can collect and store data in this format, and analysts can later load and query it using the DuckDB CLI or integrations with tools like Tableau and Apache Arrow.

Feedback

Thank you for being part of our community! If you have any general feedback or found any bugs on these pages, we welcome and encourage your input. Please submit your feedback in the InfluxDB community Slack.