mikejihbe/metrics

Standard deviation is Nan

Open

#51 创建于 2017年10月3日

在 GitHub 查看
 (0 评论) (0 反应) (0 负责人)JavaScript (575 star) (58 fork)batch import
help wanted

描述

My service is outputting metrics to Grafana but it's end points are never called. What I'm finding is that the standard deviation value is NaN, output via:

send(util.format('%s.%s', histogram.name, 'stddev'), histogram.stdDev(), timestamp);

in graphite-reporter.js. I suspect this should output zero.

贡献者指南

技术栈
javascriptnodejs
领域
backendobservability
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
2
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
under 1 hour
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
fresh
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
basic JavaScriptunderstanding of standard deviation
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
90
研究方向
Look at the `graphite reporter.js` file in the repository, specifically the line that calls `histogram.stdDev()` and then formats the output. The standard deviation calculation likely returns NaN when there are no data points or all values are equal. Modify the code to output 0 when the result is NaN, e.g., by using `isNaN()` check before sending the metric. Test with a histogram that has no observations to verify the fix.