On Sat, Aug 30, 2014 at 11:32 PM, Noah Misch <n...@leadboat.com> wrote: > On Tue, Aug 26, 2014 at 10:17:05AM +0100, Dave Page wrote: >> On Tue, Aug 26, 2014 at 1:46 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> > For the last month or so, these two buildfarm animals (which I believe are >> > the same physical machine) have been erratically failing with errors that >> > reflect low-order differences in floating-point calculations. >> > >> > A recent example is at >> > >> > http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=protosciurus&dt=2014-08-25%2010%3A39%3A52 >> > >> > where the only regression diff is >> > >> > *** >> > /export/home/dpage/pgbuildfarm/protosciurus/HEAD/pgsql.22860/src/test/regress/expected/hash_index.out >> > Mon Aug 25 11:41:00 2014 >> > --- >> > /export/home/dpage/pgbuildfarm/protosciurus/HEAD/pgsql.22860/src/test/regress/results/hash_index.out >> > Mon Aug 25 11:57:26 2014 >> > *************** >> > *** 171,179 **** >> > SELECT h.seqno AS i8096, h.random AS f1234_1234 >> > FROM hash_f8_heap h >> > WHERE h.random = '-1234.1234'::float8; >> > ! i8096 | f1234_1234 >> > ! -------+------------ >> > ! 8906 | -1234.1234 >> > (1 row) >> > >> > UPDATE hash_f8_heap >> > --- 171,179 ---- >> > SELECT h.seqno AS i8096, h.random AS f1234_1234 >> > FROM hash_f8_heap h >> > WHERE h.random = '-1234.1234'::float8; >> > ! i8096 | f1234_1234 >> > ! -------+------------------- >> > ! 8906 | -1234.12356777216 >> > (1 row) >> > >> > UPDATE hash_f8_heap >> > >> > ... a result that certainly makes no sense. The results are not >> > repeatable, failing in equally odd ways in different tests on different >> > runs. This is happening in all the back branches too, not just HEAD. > >> I have >> no idea what is causing the current issue - the machine is stable >> software-wise, and only has private builds of dependency libraries >> update periodically (which are not used for the buildfarm). If I had >> to hazard a guess, I'd suggest this is an early symptom of an old >> machine which is starting to give up. > > Agreed. Rerunning each animal against older commits would test that theory. > Say, run against the last 6 months of REL9_0_STABLE commits. If those runs > show today's failure frequencies instead of historic failure frequencies, it's > not a PostgreSQL regression. Not that I see a commit back-patched near the > time of the failure uptick (2014-08-06) that looks remotely likely to have > introduced such a regression. > > It would be sad to lose our only buildfarm coverage of plain Solaris and of > the Sun Studio compiler, but having buildfarm members this unstable is a pain. > Perhaps have those animals retry the unreliable steps up to, say, 7 times?
That would require changes to the buildfarm client. I'll see if I can find some alternate resources we can use. -- Dave Page Blog: http://pgsnake.blogspot.com Twitter: @pgsnake EnterpriseDB UK: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
