Operations & Configuration

Every feature in this group is implemented and verified, each with unit and integration coverage in the repo test suite.

What It Does

Operations and configuration cover startup initialization, environment variable interpolation, configuration schema validation, plugin lifecycle execution, and runtime auto-tuning.

Auto Tuner

The Auto-Tuner continuously monitors load patterns (RPS, latency, CPU utilization, active socket counts) over an observation window to recommend or apply resource tuning:

• Tuned Parameters: Connection pool size, worker thread count, memory buffer allocations, and timeout budgets.
• Modes: Defaults to safeMode: true (read-only advisory recommendations). When safe mode is disabled, parameters are tuned in-memory.

Config Loader and Validator

Provides zero-dependency configuration loading and validation using strictly Node.js standard libraries:

• Shape Guarantee: Enforces root object structure, semantic version patterns (^\d+\.\d+\.\d+$), and valid environments (development, staging, production).
• Variable Interpolation: Replaces ${ENV_VAR} and fallback ${ENV_VAR:defaultValue} syntax recursively within string attributes before schema checks.
• Version Migrations: Automatically applies backward-compatible configuration migrations between schema versions.

Plugin Execution Chain

The gateway’s extension mechanism provides modular interceptors without modifying core pipeline code:

• Lifecycle Stages: preRoute (rate limiting, early auth), preHandler (header enrichment), postHandler (auditing), and onError (custom error mapping).
• Execution Guarantees: Plugins run in deterministic registered order. Any plugin returning a response short-circuits the rest of the chain.
• Timeout Isolation: Individual plugin execution is bounded by timeout timers, preventing third-party plugins from hanging requests.

Configuration

Operational behavior is driven by gateway.config.json and loader options:

Option	Type	Default	Effect
version	string	"1.0.0"	Configuration schema version pattern ^\d+\.\d+\.\d+$.
environment	string	"production"	Runtime environment name (development, staging, production).
server.port	number	3000	Gateway listen port (1 to 65535).
server.host	string	"0.0.0.0"	Binding network interface address.
plugins[].name	string	—	Unique registered identifier of the plugin.
plugins[].enabled	boolean	true	Toggles execution of this plugin in the pipeline.
plugins[].priority	number	0	Execution priority order (higher runs first).
performance.autoTuning.enabled	boolean	false	Enables periodic performance observation and tuning.
performance.autoTuning.safeMode	boolean	true	Restricts auto-tuner to advisory recommendations.
performance.autoTuning.windowMs	number	300000	Observation window duration in milliseconds (5 minutes).

Interactions

Operations and plugins coordinate startup and request execution:

1. Bootstrapping: ConfigLoader.load() reads the configuration file, interpolates environment variables, validates types and ranges, and initializes the server.
2. Plugin Registration: Enabled plugins are registered into PluginManager, validated for unique names, and sorted by priority.
3. Inbound Dispatch: Server runs the preRoute plugin chain. If a plugin emits a Response, the pipeline short-circuits and bypasses downstream handlers.
4. Outbound Dispatch: After upstream proxying, postHandler plugins inspect or modify outbound payloads.
5. Periodic Telemetry: The Auto-Tuner samples MetricsCollector every observation window to evaluate connection saturation and latency drift.

Tradeoffs and Failure Modes

• Advisory vs Autonomous Tuning: Running safeMode: true prevents automated changes from destabilizing production, requiring operators to review recommendations. Autonomous mode adjusts in-memory parameters but does not mutate the persistent gateway.config.json file.
• Fail-Fast Boot Validation: If any configuration property is invalid, missing, or references an undefined strict environment variable, the loader throws an aggregated error and halts startup immediately. This prevents running with partial or unsafe defaults.
• Plugin Timeout Penalties: If a custom plugin hangs, the plugin timeout manager aborts the execution with an error, preventing misbehaving plugins from exhausting the request budget.
• Hot-Reload Constraints: While route and upstream tables support runtime registration, socket listener attributes (such as port or worker count) require a full process restart to take effect.