prometheus 指标大小抓取

一：最大限制数

Prometheus large scrape - alert: PrometheusLargeScrape expr: increase(prometheus_target_scrapes_exceeded_sample_limit_total[10m]) > 10 for: 5m labels: severity: warning annotations: summary: Prometheus large scrape (instance {{ $labels.instance }}) description: "Prometheus has many scrapes that exceed the sample limit\n VALUE = {{ $value }}\n LABELS = {{ $labels }}"

expr: increase(prometheus_target_scrapes_exceeded_sample_limit_total[10m]) > 10

解读：

用于检测Prometheus抓取目标时是否频繁超过样本限制

prometheus_target_scrapes_exceeded_sample_limit_total 是一个计数器指标，记录了因超过样本限制而被拒绝的抓取次数

increase() 函数计算这个指标在指定时间范围内的增量

二：重复性抓取检测

Prometheus target scrape duplicate - alert: PrometheusTargetScrapeDuplicate expr: increase(prometheus_target_scrapes_sample_duplicate_timestamp_total[5m]) > 0 for: 0m labels: severity: warning annotations: summary: Prometheus target scrape duplicate (instance {{ $labels.instance }}) description: "Prometheus has many samples rejected due to duplicate timestamps but different values\n VALUE = {{ $value }}\n LABELS = {{ $labels }}"

expr: increase(prometheus_target_scrapes_sample_duplicate_timestamp_total[5m]) > 0

解读：

prometheus_target_scrapes_sample_duplicate_timestamp_total 是一个计数器指标，记录了因重复时间戳而被拒绝的样本数量