DNS and SQLite Integration

Input and output integration overview

The DNS plugin enables users to monitor and gather statistics on DNS query times, facilitating performance analysis of DNS resolutions.

Telegraf’s SQL output plugin stores metrics in an SQL database by creating tables dynamically for each metric type. When configured for SQLite, it utilizes a file-based DSN and a minimal SQL schema tailored for lightweight, embedded database usage.

Integration details

DNS

This plugin gathers DNS query times in milliseconds, utilizing the capabilities of DNS queries similar to the Dig command. It provides a means to monitor and analyze DNS performance by measuring the response time from specified DNS servers, allowing network administrators and engineers to ensure optimal DNS resolution times. The plugin can be configured to target specific servers and customize the types of records queried, encompassing various DNS features such as resolving domain names to IP addresses, or retrieving details from specific records as needed, while also clearly reporting on the success or failure of each query, alongside relevant metadata.

SQLite

The SQL output plugin writes Telegraf metrics to an SQL database using a dynamic schema where each metric type corresponds to a table. For SQLite, the plugin uses the modernc.org/sqlite driver and requires a DSN in the format of a file URI (e.g., ‘file:/path/to/telegraf.db?cache=shared’). This configuration leverages standard ANSI SQL for table creation and data insertion, ensuring compatibility with SQLite’s capabilities.

Configuration

DNS

[[inputs.dns_query]]
  servers = ["8.8.8.8"]

  # network = "udp"

  # domains = ["."]

  # record_type = "A"

  # port = 53

  # timeout = "2s"

  # include_fields = []
  

SQLite

[[outputs.sql]]
  ## Database driver
  ## Valid options: mssql (Microsoft SQL Server), mysql (MySQL), pgx (Postgres),
  ## sqlite (SQLite3), snowflake (snowflake.com), clickhouse (ClickHouse)
  driver = "sqlite"

  ## Data source name
  ## For SQLite, the DSN is a filename or URL with the scheme "file:".
  ## Example: "file:/path/to/telegraf.db?cache=shared"
  data_source_name = "file:/path/to/telegraf.db?cache=shared"

  ## Timestamp column name
  timestamp_column = "timestamp"

  ## Table creation template
  ## Available template variables:
  ##  {TABLE}        - table name as a quoted identifier
  ##  {TABLELITERAL} - table name as a quoted string literal
  ##  {COLUMNS}      - column definitions (list of quoted identifiers and types)
  table_template = "CREATE TABLE {TABLE} ({COLUMNS})"

  ## Table existence check template
  ## Available template variables:
  ##  {TABLE} - table name as a quoted identifier
  table_exists_template = "SELECT 1 FROM {TABLE} LIMIT 1"

  ## Initialization SQL (optional)
  init_sql = ""

  ## Maximum amount of time a connection may be idle. "0s" means connections are never closed due to idle time.
  connection_max_idle_time = "0s"

  ## Maximum amount of time a connection may be reused. "0s" means connections are never closed due to age.
  connection_max_lifetime = "0s"

  ## Maximum number of connections in the idle connection pool. 0 means unlimited.
  connection_max_idle = 2

  ## Maximum number of open connections to the database. 0 means unlimited.
  connection_max_open = 0

  ## Metric type to SQL type conversion
  ## The values on the left are the data types Telegraf has and the values on the right are the SQL types used when writing to SQLite.
  #[outputs.sql.convert]
  #  integer       = "INT"
  #  real          = "DOUBLE"
  #  text          = "TEXT"
  #  timestamp     = "TIMESTAMP"
  #  defaultvalue  = "TEXT"
  #  unsigned      = "UNSIGNED"
  #  bool          = "BOOL"

Input and output integration examples

DNS

1. Monitor DNS Performance for Multiple Servers: By deploying the DNS plugin, a user can simultaneously monitor the performance of different DNS servers, such as Google DNS and Cloudflare DNS, by specifying them in the servers array. This scenario enables comparisons of response times and reliability across different DNS providers, assisting in selecting the best option based on empirical data.

2. Analyze Query Times for High-Traffic Domains: Integrate the plugin to measure response times specifically for high-traffic domains relevant to an organization’s operations, such as internal services or customer-facing sites. By focusing on performance metrics for these domains, organizations can proactively address latency issues, ensuring service reliability and improving user experiences.

3. Alerting on DNS Timeouts: Utilize the plugin in combination with alerting systems to notify administrators whenever a DNS query exceeds a defined timeout threshold. This setup can help in proactive troubleshooting of networking issues or server misconfigurations, fostering a rapid response to potential downtime scenarios.

4. Gather Historical Data for Performance Trends: Use the plugin to collect historical data on DNS query times over extended periods. This data can be used to analyze trends and patterns in DNS performance, enabling better capacity planning, identifying periodic issues, and justifying infrastructure upgrades or changes to DNS architectures.

SQLite

1. Local Monitoring Storage: Configure the plugin to write metrics to a local SQLite database file. This is ideal for lightweight deployments where setting up a full-scale database server is not required.
2. Embedded Applications: Use SQLite as the backend for applications embedded in edge devices, benefiting from its file-based architecture and minimal resource requirements.
3. Quick Setup for Testing: Leverage SQLite’s ease of use to quickly set up a testing environment for Telegraf metrics collection without the need for external database services.
4. Custom Schema Management: Adjust the table creation templates to predefine your schema if you require specific column types or indexes, ensuring compatibility with your application’s needs.

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.