[pytest-dev] pytest-xdist-1.11: restarting crash nodes, fixture cache fix

[holger krekel]

On Thu, Sep 18, 2014 at 20:51 +0200, Anatoly Bubenkov wrote:
> hmm, but that grouping is not important for session scoped fixtures, right?
> i mean, what's the sense of tearing down the session-scoped fixture, even
> if most likely it will be not used by any test, earlier than the end of the
> session?

Parametrized session-scoped fixtures, for example, may depend on being torn
down, not all be active at the same time.  In any case, it's part of a
general scheme to teardown fixtures as early as possible, not as late as
possible.  We can discuss/play with that and introduce an option which
prohibits it, possibly.

best,
holger

P.S: i bet you are using gmail, right? (because of your top-level 
posting style -- i often prefer inlined comments because it allows to
get statements in context).

> it should be ok for that fixture to live till the end of the session, and
> then any randomization should not matter
> i agree that for modules and classes grouping is nice, though
> 
> 
> On 18 September 2014 20:46, holger krekel <holger at merlinux.eu> wrote:
> 
> > On Thu, Sep 18, 2014 at 20:35 +0200, Anatoly Bubenkov wrote:
> > > yes per testing subprocess, as i've already asked in the comments section
> > > on the paylogic developer portal, im waiting for your confirmation that's
> > > NOT by design that we were getting multiple test sessions per test
> > > subprocess
> > > so i'll need to fix the article then
> >
> > yes, it's not by design.  It was more an implementation incident.
> >
> > > BTW: now im reading the code again, it looks like even with randomization
> > > plugin it should not matter?
> >
> > pytest relies on the following property of test collections: if a test
> > at index I1 uses a session-scoped fixture X and at an index I2>I1 X is not
> > used than for any I3>I2 X will not be used, either.  If this is not
> > true for any given testing process then the fixture will be torn down
> > and setup again (at I3).  pytest groups tests so in general this property
> > is true (see here:
> >
> > https://pytest.org/latest/fixture.html#automatic-grouping-of-tests-by-fixture-instances
> > for how it groups).
> >
> > If you have multiple parametrized session-scoped fixtures (not very common)
> > or item randomization the above property is likely not true but that
> > already
> > is true then for single-process execution.
> >
> > best,
> > holger
> >
> > > On 18 September 2014 20:31, holger krekel <holger at merlinux.eu> wrote:
> > >
> > > > On Thu, Sep 18, 2014 at 20:24 +0200, Anatoly Bubenkov wrote:
> > > > > so, this is again guaranteed that there will be only one session per
> > test
> > > > > run on any test slave?
> > > >
> > > > there is always one session object only but i think you are asking if a
> > > > session-scoped fixture will only be instantiated once per testing
> > > > subprocess, right?  In general this should be the case if i am not
> > missing
> > > > something (when you use a test randomization plugin, then it's probably
> > > > not the case).
> > > >
> > > > best,
> > > > holger
> > > >
> > > > > On 18 September 2014 20:23, Anatoly Bubenkov <bubenkoff at gmail.com>
> > > > wrote:
> > > > >
> > > > > > Great!
> > > > > > thanks a lot everyone involved
> > > > > >
> > > > > > On 18 September 2014 20:21, holger krekel <holger at merlinux.eu>
> > wrote:
> > > > > >
> > > > > >>
> > > > > >> I just released pytest-xdist-1.11, the distributed testing plugin
> > for
> > > > > >> pytest.
> > > > > >> It introduces automatic restarting of crashed nodes, courtesy of a
> > > > > >> complete PR from Floris Bruynooghe.  This also works well together
> > > > with
> > > > > >> pytest-timeout by the same author: When one or more test functions
> > > > hang
> > > > > >> or crash, the overall test run will still complete and report
> > about
> > > > the
> > > > > >> incidents.  See the changelog below for more changes and the pypi
> > > > > >> project page for what pytest-xdist offers in general:
> > > > > >>
> > > > > >>     https://pypi.python.org/pypi/pytest-xdist/
> > > > > >>
> > > > > >> Thanks also to an undisclosed company who partly funded the work
> > > > > >> and to Andreas Pelme for contributing analysis of a fixture
> > caching
> > > > > >> failure including a test.
> > > > > >>
> > > > > >> best,
> > > > > >> Holger Krekel
> > > > > >>
> > > > > >>
> > > > > >> 1.11
> > > > > >> -------------------------
> > > > > >>
> > > > > >> - fix pytest/xdist issue485 (also depends on py-1.4.22):
> > > > > >>   attach stdout/stderr on --boxed processes that die.
> > > > > >>
> > > > > >> - fix pytest/xdist issue503: make sure that a node has usually
> > > > > >>   two items to execute to avoid scoped fixtures to be torn down
> > > > > >>   pre-maturely (fixture teardown/setup is "nextitem" sensitive).
> > > > > >>   Thanks to Andreas Pelme for bug analysis and failing test.
> > > > > >>
> > > > > >> - restart crashed nodes by internally refactoring setup handling
> > > > > >>   of nodes.  Also includes better code documentation.
> > > > > >>   Many thanks to Floris Bruynooghe for the complete PR.
> > > > > >>
> > > > > >> _______________________________________________
> > > > > >> Pytest-dev mailing list
> > > > > >> Pytest-dev at python.org
> > > > > >> https://mail.python.org/mailman/listinfo/pytest-dev
> > > > > >>
> > > > > >
> > > > > >
> > > > > >
> > > > > > --
> > > > > > Anatoly Bubenkov
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Anatoly Bubenkov
> > > >
> > >
> > >
> > >
> > > --
> > > Anatoly Bubenkov
> >
> 
> 
> 
> -- 
> Anatoly Bubenkov