express.js

'use strict';
const express = require('express');
const app = express();
const Influx = require('..');
const _ = require('lodash');
const client = new Influx('http://red:8086/mydb');
const onHeaders = require('on-headers');

// set the http stats schema
client.schema('http', {
  use: 'integer',
  code: 'integer',
  bytes: 'integer',
  url: 'string',
});
client.on('writeQueue', () => {
  // sync write queue if the length is 100
  if (client.writeQueueLength === 100) {
    client.syncWrite()
      .then(() => {
        console.info('sync write success');
      })
      .catch(console.error);
  }
});

function httpStats(req, res, next) {
  const start = Date.now();
  onHeaders(res, () => {
    const code = res.statusCode;
    const use = Date.now() - start;
    const method = req.method;
    const bytes = parseInt(res.get('Content-Length') || 0, 10);
    const tags = {
      spdy: _.sortedIndex([100, 300, 1000, 3000], use),
      type: code / 100 | 0,
      method,
    };
    const fields = {
      use,
      code,
      bytes,
      url: req.url,
      route: req.route.path
    };
    // use queue for better performance
    client.write('http')
      .tag(tags)
      .field(fields)
      .queue();
  });
  next();
}

client.createDatabase().catch(err => {
  console.error('create database fail err:', err);
});

app.use(httpStats);

app.use((req, res, next) => {
  setTimeout(next, _.random(0, 5000));
});

app.get('/users/me', (req, res) => {
  res.json({
    account: 'vicanso',
    name: 'Tree Xie',
  });
});

app.get('/book/:id', (req, res) => {
  const {
    id,
  } = req.params;
  res.json({
    id: id,
    name: 'my book',
    author: 'vicanso',
  });
});

app.get('/order/:id', (req, res) => {
  const code = _.sample([200, 304, 400, 403]);
  switch (code) {
    case 304:
      res.status(304).send('');
      break;
    case 400:
      res.status(400).json({
        error: 'The id is not valid',
      });
      break;
    case 403:
      res.status(403).json({
        error: 'Please login first',
      });
      break;
    default:
      res.json({
        account: 'vicanso',
      });
      break;
  }
});

app.get('/author/:id', (req, res) => {
  const code = _.sample([200, 304, 500]);
  switch (code) {
    case 304:
      res.status(304).send('');
      break;
    case 500:
      res.status(500).json({
        error: 'The database is disconnected',
      });
      break;
    default:
      res.json({
        account: 'vicanso',
      });
      break;
  }
});

let server;
const finish = () => {
  console.info(`listen on http://127.0.0.1:${server.address().port}/`);
};
if (process.env.PORT) {
  server = app.listen(process.env.PORT, finish);
} else {
  server = app.listen(finish);
}