@ca-apm/native-metrics/index.js

Monitor Native matrics like GC and Event loop stats

/**
 * Copyright (c) 2015 CA. All rights reserved.
 *
 * This software and all information contained therein is confidential and proprietary and
 * shall not be duplicated, used, disclosed or disseminated in any way except as authorized
 * by the applicable license agreement, without the express written permission of CA. All
 * authorized reproductions must be marked with this language.
 *
 * EXCEPT AS SET FORTH IN THE APPLICABLE LICENSE AGREEMENT, TO THE EXTENT
 * PERMITTED BY APPLICABLE LAW, CA PROVIDES THIS SOFTWARE WITHOUT WARRANTY
 * OF ANY KIND, INCLUDING WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OF
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL CA BE
 * LIABLE TO THE END USER OR ANY THIRD PARTY FOR ANY LOSS OR DAMAGE, DIRECT OR
 * INDIRECT, FROM THE USE OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, LOST
 * PROFITS, BUSINESS INTERRUPTION, GOODWILL, OR LOST DATA, EVEN IF CA IS
 * EXPRESSLY ADVISED OF SUCH LOSS OR DAMAGE.
 */
var gcstats = require('./lib/gcstats');
var eventloopstats = require('./lib/eventloopstats');
var agent = require('ca-apm-probe/lib/agent');
var metrics = require('ca-apm-probe/lib/metrics');
var metricsReporter = metrics.getReporter();
var logger = require("ca-apm-probe/lib/logger.js");
var commonUtil = require('ca-apm-probe/lib/utils/common-utils');

gcstats.init(agent);

agent.on('poll::start', function() {
  if (data = eventloopstats.poll()) {
      agent.internal.emit('loop', {loop: data});
  }
});

agent.internal.on('send', function(name, value) {

  var resMetricPrefix = commonUtil.getResMetricPrefix();

  // FIXME(bnoordhuis) Contrary to what the name suggests, this metric is
  // actually a mix of scavenges and full GCs.
  if (name === 'update' && value.name === 'GC Full. V8 heap used') {
      var gcHeapUsed = value.value || 0;
      logUpdates('gc.heap.used', gcHeapUsed);
      metricsReporter.reportFluctuatingCounterMetric(resMetricPrefix + 'GC Heap Used', gcHeapUsed);
      return;
  }

  if (name === 'update' && typeof(value.loop) === 'object') {
      logUpdates('loop.count', value.loop.count | 0);
      logUpdates('loop.minimum', value.loop.fastest_ms | 0);
      logUpdates('loop.maximum', value.loop.slowest_ms | 0);
      logUpdates('loop.average', commonUtil.fix(value.loop.sum_ms / (value.loop.count)));

      var count = value.loop.count;
      var avg = value.loop.sum_ms/count;  //count == 0 is handled in loop.js

      metricsReporter.reportIntervalCounterMetric(resMetricPrefix + 'Event Loop Ticks Per Interval', count);
      metrics.reportAvgDurationDirectMetric(resMetricPrefix + 'Event Loop Average Tick Time(ms)', avg, value.loop.fastest_ms, value.loop.slowest_ms, count);
      return;
    }
});

function logUpdates(name, value){
  logger.debug('%s=%d', name, value);
}