| 2012-09-18 10:18:14 |
Matthew Paul Thomas |
description |
Currently, the graph for "Average errors per day" is per calendar day. This is almost certainly why the graph spikes every weekend: apparently people who use Ubuntu during weekends do so for longer periods than those who use it during weekdays.
Measuring by calendar day has some subjective value: "Ubuntu crashed for me twice yesterday" is more memorable than "Ubuntu crashed for me about once every three hours yesterday".
However, there are big problems with measuring things this way. It means, for example, that if people used Ubuntu for shorter periods, the error rate would go down. Conversely, if the proportion of Ubuntu use in workplaces went up -- so people were using it for longer periods on average -- the errors/day rate would go up, even if nothing about the code changed.
To fix this, we should change "errors/day" to "errors/hour" or even "errors per 24 hours".
To do that, probably we will need to know -- for each error report submitted -- how long Ubuntu had been running when the error occurred. (This might be as simple as including the output of the "uptime" command in every error report.)
We may be able to extrapolate, from the distribution of times, to guess how long an Ubuntu session continues after the last error is submitted. If not, we might also need to know the total duration of the *previous* Ubuntu session, now that it's finished, so we can divide the number of errors that machine reported in *that* session by the length of the session. |
Currently, the graph for "Average errors per day" is per calendar day. This is almost certainly why the graph dips every weekend: apparently people who use Ubuntu during weekdays do so for longer periods than those who use it during weekends.
Measuring by calendar day has some subjective value: "Ubuntu crashed for me twice yesterday" is more memorable than "Ubuntu crashed for me about once every three hours yesterday".
However, there are big problems with measuring things this way. It means, for example, that if people used Ubuntu for shorter periods, the error rate would go down. Conversely, if the proportion of Ubuntu use in workplaces went up -- so people were using it for longer periods on average -- the errors/day rate would go up, even if nothing about the code changed.
To fix this, we should change "errors/day" to "errors/hour" or even "errors per 24 hours".
To do that, probably we will need to know -- for each error report submitted -- how long Ubuntu had been running when the error occurred. (This might be as simple as including the output of the "uptime" command in every error report.)
We may be able to extrapolate, from the distribution of times, to guess how long an Ubuntu session continues after the last error is submitted. If not, we might also need to know the total duration of the *previous* Ubuntu session, now that it's finished, so we can divide the number of errors that machine reported in *that* session by the length of the session. |
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