starrocks/fe/connector

StarRocks Data Source Connectors

This directory is the home for data source connector implementations and FE-side integration. Each connector is an independent module that implements the contracts defined in fe/spi, enabling StarRocks to query heterogeneous external data sources.

Responsibilities

• Provide concrete implementations of FE SPI for external catalogs and tables.
• Bridge StarRocks FE planning/execution with external metadata and I/O.
• Offer minimal integration and shared FE-side utilities for connectors.

Relationship to FE SPI

• FE core programs against interfaces defined in fe/spi.
• Connectors implement those interfaces and are discovered/loaded by FE.
• Keep implementations decoupled from FE internals beyond the SPI boundary.

Where things live

• This package: FE-side integration classes and built-in connector.
• Independent connectors: separate modules that depend on fe/spi and optionally reuse helpers from here.
• Do not place FE private types into connector-facing APIs.

Implementing a new connector

1. Identify the relevant SPI interfaces in fe/spi (capabilities, metadata, scanning).
2. Create a new module for your connector; depend on fe/spi.
3. Implement the SPI contracts and provide discovery metadata (e.g., ServiceLoader entries or plugin manifest supported by StarRocks).
4. Add configuration parsing and validation; prefer explicit, typed configs.
5. Integrate with FE by registering the connector and exposing catalog(s).
6. Write tests (unit for SPI conformance; integration for end-to-end queries).

Guidelines:

• Favor stateless or explicitly thread-safe implementations.
• Fail fast on misconfiguration; return well-typed errors.
• Avoid blocking FE critical paths; use timeouts and backoff for I/O.
• Log actionable messages; never log secrets or PII.

Lifecycle

• Initialize: receive context/config, validate connectivity and schema access.
• Runtime: serve concurrent metadata and split/scan requests.
• Shutdown: release resources (clients, threads) idempotently.

Configuration

• Use namespaced keys for connector-specific options.
• Support secure credentials handling (env/keystore/injected secrets).
• Provide sensible defaults and minimal required options.

Compatibility and versioning

• Track the fe/spi version your connector supports.
• Prefer backward-compatible changes; deprecate before breaking.
• Document supported external system versions and features.

Testing

• Unit tests against SPI interfaces with mocks/fakes.
• Integration tests that query real or embedded backends where feasible.
• Include negative tests for permissions, schema drift, and network failures.

Security considerations

• Enforce authorization checks exposed via SPI contexts.
• Sanitize external inputs; validate identifiers and filter expressions.
• Obfuscate or omit sensitive fields from logs and error messages.

References

• FE SPI (contracts): fe/spi/
• FE connector integration: this package (com.starrocks.connector)
• Project docs: https://docs.starrocks.io/