全局配置

global 属于全局的默认配置，它主要包含 4 个属性，

  • scrape_interval: 拉取 targets 的默认时间间隔。
  • scrape_timeout: 拉取一个 target 的超时时间。
  • evaluation_interval: 执行 rules 的时间间隔。
  • external_labels: 额外的属性，会添加到拉取的数据并存到数据库中。

其代码结构体定义为：

  1.  // GlobalConfig configures values that are used across other configuration
  2. // objects.
  3. type GlobalConfig struct {
  4.     // How frequently to scrape targets by default.
  5.     ScrapeInterval model.Duration `yaml:"scrape_interval,omitempty"`
  6.     // The default timeout when scraping targets.
  7.     ScrapeTimeout model.Duration `yaml:"scrape_timeout,omitempty"`
  8.     // How frequently to evaluate rules by default.
  9.     EvaluationInterval model.Duration `yaml:"evaluation_interval,omitempty"`
  10.     // The labels to add to any timeseries that this Prometheus instance scrapes.
  11.     ExternalLabels model.LabelSet `yaml:"external_labels,omitempty"`
  13.     // Catches all undefined fields and must be empty after parsing.
  14.     XXX map[string]interface{} `yaml:",inline"`
  15. }

配置文件结构大概为：

  1. global:
  2.   scrape_interval:     15s # By default, scrape targets every 15 seconds.
  3.   evaluation_interval: 15s # By default, scrape targets every 15 seconds.
  4.   scrape_timeout: 10s # is set to the global default (10s).
  6.   # Attach these labels to any time series or alerts when communicating with
  7.   # external systems (federation, remote storage, Alertmanager).
  8.   external_labels:
  9.     monitor: 'codelab-monitor'