Measure time and responses

sc.js

// Measure time and responses
// usage: while [ 1 ]; do node sc.js; sleep 5; done
//    or: while [ 1 ]; do SC_HEARTBEAT=1 node sc.js; sleep 5; done

var http = require('http');

var path, heartbeat;
if (process.env.SC_HEARTBEAT) {
  heartbeat = true;
  path = '/__heartbeat__';
} else {
  path = '/wsapi/session_context';
}

var options = {
  hostname: '127.0.0.1',
  port: 63300, // router daemon
  path: path
};

function get_payload(data) {
  if (heartbeat) return data === 'ok';
  try {
    info = JSON.parse(data);
  } catch(e) {
    console.log(new Date().toISOString(), 'exception', e);
  }
  return info;
}

function session_context() {
  var start = Date.now();

  var req = http.get(options, function(res) {
    var elapsed = Date.now() - start;
    var data = '';
    res.setEncoding('utf8');

    res.on('data', function(chunk) {
      data += chunk;
    });

    res.on('end', function() {
      var info = get_payload(data);
      var parseable = !!info;
      var ok = (res.statusCode === 200 && parseable) ? 'PASS' : 'FAIL'; 
      console.log(new Date().toISOString(), 'status:', ok, res.statusCode, elapsed + 'ms');
    });
  });

  req.on('error', function(e) {
    var elapsed = Date.now() - start;
    console.log(new Date().toISOString(), 'error:', e.message, elapsed + 'ms');
  });
}

session_context();