Prometheus Java simpleclient Custom Collector 指标是否应该在每个集合上实例化？

Question

在 simpleclient Java README 示例中 Collector 如下所示：

class YourCustomCollector extends Collector {
  List<MetricFamilySamples> collect() {
    List<MetricFamilySamples> mfs = new ArrayList<MetricFamilySamples>();
    // With no labels.
    mfs.add(new GaugeMetricFamily("my_gauge", "help", 42));
    // With labels
    GaugeMetricFamily labeledGauge = new GaugeMetricFamily("my_other_gauge", "help", Arrays.asList("labelname"));
    labeledGauge.addMetric(Arrays.asList("foo"), 4);
    labeledGauge.addMetric(Arrays.asList("bar"), 5);
    mfs.add(labeledGauge);
    return mfs;
  }
}

// Registration
static final YourCustomCollector requests = new YourCustomCollector().register()

是否必须在每次调用 collect 时实例化指标，或者实例化一次然后在 collect 中调用 addMetric 是否合理？如果不是，这种方法会出现什么问题？

Answer 1

是的，MetricFamilies 应该（几乎）总是在每次收集时重新实例化。

would it be reasonable to instantiate them once and then just call addMetric in collect?

这不是线程安全的，您还需要做一些事情来跨集合清除它。

Prometheus Java simpleclient Custom Collector 指标是否应该在每个集合上实例化？

Should Prometheus Java simpleclient Custom Collector metrics be instantiated on every collection?

java

prometheus