错误率与缓存命中率
错误率与缓存命中率
# 5xx 错误率（全局）
sum(rate(http_requests_total{code=~"5.."}[5m]))
/ sum(rate(http_requests_total[5m]))
# 按服务分组（分子分母维度一致）
sum by (service) (rate(http_requests_total{code=~"5.."}[5m]))
/ sum by (service) (rate(http_requests_total[5m]))
# 缓存命中率
sum(rate(cache_hits_total[5m])) / (sum(rate(cache_hits_total[5m])) + sum(rate(cache_misses_total[5m])))分母为 0 时结果是 NaN 或 +Inf；看板要设置空值显示方式，告警表达式里先确认分母非零。