[Popcon-developers] How long should we keep old submissions?
On Fri, Apr 02, 2004 at 05:31:44PM +0200, Petter Reinholdtsen wrote:
> I've been thinking about when we delete old submissions. At the
> moment, we delete them if they are older than 20 days, and earlier we
> deleted them if they were older than 10 days. On the other hand, the
> machines are supposed to submit new entries every 7 day. I believe
> that is the reason the graphs vere moving up and down as they were
> when we deleted old entries after 10 days.
>
> So I am woundering, should the delete period be a multiple of the
> submit period? 7, 14, 21, 28 days? I suspect this would give less
> wave pattern in the graphs. If not, why not?
As long as the expiration happens *after* 7 days of inactivity, then the
weekly submission event on each box is guaranteed to have happened during
the expiration period, so if they're not there, they've really expired. You
really shouldn't see much difference in results as long as the expiration
period is "significantly greater than" the submission period (since
submissions may be delayed for some number of days in laptops, etc. that
were offline when they wanted to send in their results).
The real problem is probably people who don't run anacron, and yet aren't
always running their box at the weekly submission time. In that case they
might miss a submission entirely, and wait an extra 7 days.
An easy way to fix this is just to greatly increase the time before expiry:
30 or 60 days would be just fine, unless you *really* need to know exactly
how many people have started/stopped using vi in the last week. This won't
waste disk space or anything, since the entry from a particular box always
immediately overwrites the previous entry from that box.
Have fun,
Avery
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