IO tWaitTime between two calls

[frufin]

Getting IO tWaitTime isn't really useful as it seems that returned value is wait time from host start.
To get usable data, we need to compute deltaWait = tWaitTime(t) - tWaitTime(t-1)

So, why not compute before outputting as you internally store last call value ?

Thanks!

[sebhildebrandt]

@frufin ... I digged into the corresponding function which is in filesystem.js line 935ff calcDiskIO()

• the percentage values, are already based on delta
• the rWaitTime, wWaitTime and tWaitTime are total (overall) numbers so far (as also stated in the docs).

You suggest to make it all based on relative numbers?

This could be the calculation:

const dt = Date.now() - _disk_io.ms;

const drWait = rWaitTime - _disk_io.rWaitTime;
const dwWait = wWaitTime - _disk_io.wWaitTime;
const dtWait = tWaitTime - _disk_io.tWaitTime;

result.rWaitTime = rWaitTime;          // cumulative
result.wWaitTime = wWaitTime;          // cumulative
result.tWaitTime = tWaitTime;          // cumulative

result.rWaitMs_interval = drWait;      // interval
result.wWaitMs_interval = dwWait;      // interval
result.tWaitMs_interval = dtWait;      // interval

result.rWaitPercent = drWait * 100 / dt;
result.wWaitPercent = dwWait * 100 / dt;
result.tWaitPercent = dtWait * 100 / dt;

BUT: For the first call than still it would be absolute numbers and therefore probably misleading ... any suggestions?