如何跟踪所有休息 api 的请求数

Question

我想跟踪每个 API 的请求数和失败数。我已经为一个 api 做到了这一点。

const http = require('http')
const url = require('url')
const client = require('prom-client')

// Create a Registry which registers the metrics
const register = new client.Registry()

// Add a default label which is added to all metrics
register.setDefaultLabels({
  app: 'example-nodejs-app'
})

// Enable the collection of default metrics
client.collectDefaultMetrics({ register })

// Create a histogram metric
const httpRequestDurationMicroseconds = new client.Histogram({
  name: 'http_request_duration_seconds',
  help: 'Duration of HTTP requests in microseconds',
  labelNames: ['method', 'route', 'code'],
  buckets: [0.1, 0.3, 0.5, 0.7, 1, 3, 5, 7, 10]
})

// Register the histogram
register.registerMetric(httpRequestDurationMicroseconds)

// Define the HTTP server
const server = http.createServer(async (req, res) => {
    // Start the timer
  const end = httpRequestDurationMicroseconds.startTimer()

  // Retrieve route from request object
  const route = url.parse(req.url).pathname

  if (route === '/order') {
    await createOrderHandler(req, res)
  }

  if (route === '/products') {
    await fetchProducts(req, res)
  }

  // End timer and add labels
  end({ route, code: res.statusCode, method: req.method })
})

// Start the HTTP server which exposes the metrics on http://localhost:8080/metrics
server.listen(8080)

我如何为所有 api 实现这一点？

Answer 1

您可以为成功和失败的 api 添加计数器

const http = require('http')
const url = require('url')
const client = require('prom-client')

// Create a Registry which registers the metrics
const register = new client.Registry()

// Add a default label which is added to all metrics
register.setDefaultLabels({
    app: 'example-nodejs-app'
})

// Enable the collection of default metrics
client.collectDefaultMetrics({register})

// Create a histogram metric
const httpRequestDurationMicroseconds = new client.Histogram({
    name: 'http_request_duration_seconds',
    help: 'Duration of HTTP requests in microseconds',
    labelNames: ['method', 'route', 'code'],
    buckets: [0.1, 0.3, 0.5, 0.7, 1, 3, 5, 7, 10]
})
let counts = {
    success: 0,
    fail: 0,
};

// Register the histogram
register.registerMetric(httpRequestDurationMicroseconds)

// Define the HTTP server
const server = http.createServer(async (req, res) => {
    // Start the timer
    const end = httpRequestDurationMicroseconds.startTimer()

    // Retrieve route from request object
    const route = url.parse(req.url).pathname

    try {
        if (route === '/order') {
            await createOrderHandler(req, res)
        }

        if (route === '/products') {
            await fetchProducts(req, res)
        }

        if (route === '/get-counts') {
            counts.success--;
            res.writeHead(200, {'Content-Type': 'application/json'});
            res.write(JSON.stringify(counts, null, 4));
            res.end();
        }
        
        if (res.statusCode === 200) {
            counts.success++;
        } else {
            counts.fail++;
        }
    } catch (e) {
        res.writeHead(500, {'Content-Type': 'text/plain'});
        res.write(e.toString());
        res.end();
        counts.fail++;
    }

    // End timer and add labels
    end({route, code: res.statusCode, method: req.method})
})

// Start the HTTP server which exposes the metrics on http://localhost:8080/metrics
server.listen(8080);

请求的总数将是成功和失败计数器的加法。

Answer 2

您可以监听res 的finish 事件，当您调用res.end 时将触发该事件。

这是一个简单的例子

import { createServer } from 'http'

const reqMap = new Map()

const updateCounts = (reqStats, statusCode) => {
  if (statusCode >= 400) reqStats.failures++
  else if (statusCode >= 200) reqStats.successes++
  else reqStats.misc++
}

const server = createServer((req, res) => {
  res.on('finish', () => {
    if (res.headersSent && req.url) {
      const reqStats = reqMap.get(req.url)
      if (reqStats) {
        updateCounts(reqStats, res.statusCode)
      } else {
        const newReqStats = { failures: 0, successes: 0, misc: 0 }
        updateCounts(newReqStats, res.statusCode)
        reqMap.set(req.url, newReqStats)
      }
      console.log(reqMap)
    }
  })

  try {
    const num = Math.random()
    if (num < 0.55) throw new Error('bad number')
    res.writeHead(200, { 'Content-Type': 'application/json' })
    res.end(JSON.stringify({ num }) + '
')
  } catch (err) {
    res.writeHead(500, { 'Content-Type': 'application/json' })
    res.end(JSON.stringify({ name: err.name, message: err.message }) + '
')
  }
})

server.on('error', console.error)

server.listen(8000, () => console.log('listening on', server.address()))

reqMap 会有这样的东西。

Map(5) {
  '/asda/asd899a' => { failures: 1, successes: 0, misc: 0 },
  '/somepath/asd' => { failures: 0, successes: 1, misc: 0 },
  '/coyb' => { failures: 0, successes: 1, misc: 0 },
  '/casd' => { failures: 3, successes: 3, misc: 0 },
  '/etst' => { failures: 5, successes: 4, misc: 0 }
}

Answer 3

我认为https://github.com/yaorg/node-measured 可能会回答您的问题，我理解它的实现类似于 Node.js 中的 Metrics (of Java world )。