Consul and DuckDB Integration

Input and output integration overview

The Consul Input Plugin collects health check metrics from a Consul server, allowing users to monitor service statuses effectively.

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

Consul

The Consul Input Plugin is designed to gather health check statuses from all services registered with Consul, a tool for service discovery and infrastructure management. By querying the Consul API, this plugin helps users monitor the health of their services and ensure that they are operational and meeting service level agreements. It does not provide telemetry data, but users can utilize StatsD if they want to collect those metrics. The plugin offers configuration options to connect to the Consul server, manage authentication, and specify how to handle tags derived from health checks.

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

Consul

[[inputs.consul]]
  ## Consul server address
  # address = "localhost:8500"

  ## URI scheme for the Consul server, one of "http", "https"
  # scheme = "http"

  ## Metric version controls the mapping from Consul metrics into
  ## Telegraf metrics. Version 2 moved all fields with string values
  ## to tags.
  ##
  ##   example: metric_version = 1; deprecated in 1.16
  ##            metric_version = 2; recommended version
  # metric_version = 1

  ## ACL token used in every request
  # token = ""

  ## HTTP Basic Authentication username and password.
  # username = ""
  # password = ""

  ## Data center to query the health checks from
  # datacenter = ""

  ## Optional TLS Config
  # tls_ca = "/etc/telegraf/ca.pem"
  # tls_cert = "/etc/telegraf/cert.pem"
  # tls_key = "/etc/telegraf/key.pem"
  ## Use TLS but skip chain & host verification
  # insecure_skip_verify = true

  ## Consul checks' tag splitting
  # When tags are formatted like "key:value" with ":" as a delimiter then
  # they will be split and reported as proper key:value in Telegraf
  # tag_delimiter = ":"

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

Consul

1. Service Health Monitoring Dashboard: Utilize the Consul Input Plugin to create a comprehensive health monitoring dashboard for all services registered with Consul. This allows operations teams to visualize the health status in real time, enabling quick identification of service issues and facilitating rapid responses to service outages or performance degradation.

2. Automated Alerting System: Implement an automated alerting system that uses the health check data gathered by the Consul Input Plugin to trigger notifications whenever a service status changes to critical. This setup can integrate with notification systems like Slack or email, ensuring that team members are alerted immediately to address potential issues.

3. Integration with Incident Management: Leverage the health check data from the Consul Input Plugin to feed into incident management systems. By analyzing the health status trends, teams can prioritize incidents based on the criticality of the affected services and streamline their resolution processes, improving overall service reliability and customer satisfaction.

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.