NSQ and SQLite Integration

Input and output integration overview

The NSQ Telegraf plugin reads metrics from the NSQD messaging system, allowing for real-time data processing and monitoring.

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

NSQ

The NSQ plugin interfaces with NSQ, a real-time messaging platform, enabling the reading of messages from NSQD. This plugin is categorized as a service plugin, meaning it actively listens for metrics and events rather than polling them at regular intervals. With an emphasis on reliability, it prevents data loss by tracking undelivered messages until they are acknowledged by outputs. The plugin allows for configurations such as specifying NSQLookupd endpoints, topics, and channels, and it supports multiple data formats for flexibility in data handling.

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

NSQ

# Read metrics from NSQD topic(s)
[[inputs.nsq_consumer]]
  ## Server option still works but is deprecated, we just prepend it to the nsqd array.
  # server = "localhost:4150"

  ## An array representing the NSQD TCP HTTP Endpoints
  nsqd = ["localhost:4150"]

  ## An array representing the NSQLookupd HTTP Endpoints
  nsqlookupd = ["localhost:4161"]
  topic = "telegraf"
  channel = "consumer"
  max_in_flight = 100

  ## Max undelivered messages
  ## This plugin uses tracking metrics, which ensure messages are read to
  ## outputs before acknowledging them to the original broker to ensure data
  ## is not lost. This option sets the maximum messages to read from the
  ## broker that have not been written by an output.
  ##
  ## This value needs to be picked with awareness of the agent's
  ## metric_batch_size value as well. Setting max undelivered messages too high
  ## can result in a constant stream of data batches to the output. While
  ## setting it too low may never flush the broker's messages.
  # max_undelivered_messages = 1000

  ## Data format to consume.
  ## Each data format has its own unique set of configuration options, read
  ## more about them here:
  ## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
  data_format = "influx"

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

NSQ

1. Real-Time Analytics Dashboard: Integrate this plugin with a visualization tool to create a dashboard that displays real-time metrics from various topics in NSQ. By subscribing to specific topics, users can monitor system health and application performance dynamically, allowing for immediate insights and timely responses to any anomalies.

2. Event-Driven Automation: Combine NSQ with a serverless architecture to trigger automated workflows based on incoming messages. This use case could involve processing data for machine learning models or responding to user actions in applications, thus streamlining operations and enhancing user experience through rapid processing.

3. Multi-Service Communication Hub: Use the NSQ plugin to act as a centralized messaging hub among different microservices in a distributed architecture. By enabling services to communicate through NSQ, developers can ensure reliable message delivery while maintaining decoupled service interactions, significantly improving scalability and resilience.

4. Metrics Aggregation for Enhanced Monitoring: Implement the NSQ plugin to aggregate metrics from multiple sources before sending them to an analytics tool. This setup enables businesses to consolidate data from various applications and services, creating a unified view for better decision-making and strategic planning.

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

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