Exot Inspector Integration with Hono

This package includes middleware for Hono, enabling automatic tracing of incoming requests and seamless integration with other features of Exot Inspector.

Compatibility

Hono is a modern, cross-runtime framework that supports various platforms. However, Exot Inspector requires specific Node.js built-in modules and officially supports only Node.js, Bun, and Deno.

Install

npm install @exotjs/hono

Usage

import { Hono } from 'hono';
import { Inspector } from '@exotjs/inspector';
import { inspectorMiddleware } from '@exotjs/hono';

const inspector = new Inspector();

const { trace } = inspector.instruments.traces;

const app = new Hono();

app.use(inspectorMiddleware({
  inspector,
}));

app.get('/', (c) => {
  return trace('hello', () => c.text('Hello Hono!'));
});

export default app;

Server Metrics

In addition to built-in request tracing, this middleware automatically collects basic server metrics, visible in the Exot App:

• Request latency
• Response status codes

Configuration

inspector: Inspector (required)

Provide the instance of the Inspector.

traceIdHeader: string

Specify the header name for the "trace ID." Set to null to disable. Default is X-Trace-Id.

Performance

The following table illustrates the performance change per request under different scenarios.

|Test|Change per request| |----|------| |Inspector deactivated|+0.24ms| |Tracing disabled (metrics only)|+0.96ms| |Tracing enabled (metrics + tracing)|+2.21ms| |Tracing enabled (metrics + 10x tracing)|+5.03ms|

As a rule of thumb, approximately ~1ms is added to each request when tracing is disabled and only server metrics are collected. If the entire inspector, including metrics, is deactivated, only negligible sub-milliseconds are added to each request. With tracing enabled and metrics collected, expect about ~2ms. The last test measures 10 nested traces, where you should expect about ~5ms overhead.

Refer to the benchmark folder for more details.

Contributing

See Contributing Guide and please follow our Code of Conduct.

License

MIT