Re: buildfarm animals and 'snapshot too old'

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Mon, May 19, 2014 at 7:58 PM, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
>> Well, the original code was put in for a reason, presumably that we were
>> getting some stale data and wanted to exclude it. So I'm unwilling to throw
>> it out altogether. If someone can propose a reasonable sanity check then I'm
>> prepared to implement it.

> While I generally agree that long-established code shouldn't be
> changed for light or transient causes, I have to admit I'm pretty
> skeptical about this particular instance. I can't think of any
> particularly compelling reason why it's BAD for an old result to show
> up. We now show the commit ID on the main page, so if you see 512abc4
> in the middle of a bunch of ef9ab5f's, you'll notice. And if you
> don't notice, so what?

Robert's got a point here. In my usage, the annoying thing is not animals
that take a long time to report in; it's the ones that lie about the
snapshot time (which is how you get "512abc4 in the middle of a bunch of
ef9ab5f's"). That is an issue of incorrect system clock, not of how long
it takes to do the run. I wonder if the buildfarm script could be taught
to get the timestamp from an NTP server somewhere? Or at least
sanity-check the system clock reading by comparing it to the newest commit
timestamp in the git repo.

regards, tom lane