Metrics can be lost if backhual is not available for more than 10 minutes [future issue]

还没有人认领这个 Issue。

Given the current metrics service implementation if we cannot publish metrics over HTTP for more than 10 minutes we will start to lose metrics payloads, this can leave chunks of delta values missing which will cause future metrics to be incorrect. We need to think of a scalable way to preserve metrics if a publish fails, perhaps by cycling metrics back into the timed cache or processing cache if they cannot be immediately sent, an infinitely sized queue could also be used but this will not scale well

首先检查当前的 metrics service 实现，尤其是 HTTP 发布流程周围使用的 timed cache 和 processing cache。确定失败的发布是如何处理的，并设计一种可扩展的保留方案；当 metrics payloads 在超过 10 分钟的中断期间不会丢失，且未来的 delta values 仍然正确时，即视为完成。

由索引模型根据 Issue 内容生成。