[Python-Dev] Changing all network-oriented tests to facilitate (virtually unlimited) parallel test execution [Issue#: 2550] (original) (raw)

Gregory P. Smith greg at krypto.org
Tue Apr 8 21:58:01 CEST 2008

On Tue, Apr 8, 2008 at 5:00 AM, Trent Nelson <tnelson at onresolve.com> wrote:

I've forwarding my most recent update to issue 2550 here such that the proposed patch (and in general, the approach to network-oriented test cases) can be vetted by a wider audience: http://bugs.python.org/file9980/trunk.2550-2.patch This patch works towards fixing a large proportion of the tests that were written in such a way that often leads to buildbot errors when port conflicts arise. With this patch applied, I can run many instances of the test suite in parallel and none of the network-oriented tests fail (which they do currently if you try and do this). Plenty of discussion (mostly me replying to my own comments) on the subject at: http://bugs.python.org/issue2550. Anyone have any issues with this new approach? I'm particularily interested in whether or not people disagree with the assumption I've drawn regarding never using SOREUSEADDR in tests for TCP/IP sockets (see below). Trent.

I think your assumptions are fair.

Note that not using SO_REUSEADDR can reserve the port for a few minutes beyond the actual unbinding destruction of the server socket on some OSes but with tens of thousands of ports available and likely not more than 1-200 being needed by a full test suite run and how long the test suite takes to run I think that is acceptable and is not a problem we're likely to ever run into (fix it only iffwe ever do).

-gps

From: python-bugs-list-bounces+tnelson=onresolve.com at python.org[python-bugs-list-bounces+tnelson=_ _onresolve.com at python.org] On Behalf Of Trent Nelson [_ _report at bugs.python.org] Sent: 08 April 2008 12:49 To: python-bugs-list at python.org Subject: [issue2550] SOREUSEADDR doesn't have the same semantics on Windows as on Unix Trent Nelson <tnelson at onresolve.com> added the comment: Invested quite a few cycles on this issue last night. The more time I spent on it, the more I became convinced that every single test working with sockets should be changed in one fell swoop in order to facilitate (virtually unlimited) parallel test execution without fear of port conflicts. I've attached a second patch, trunk.2550-2.patch, which is my progress so far on doing just this. The main changes can be expressed by the following two points: a) do whatever it takes in network-oriented tests to ensure unique ports are obtained (relying on the bindport() and findunusedport() methods exposed by testsupport) b) never, ever, ever call SOREUSEADDR on a socket from a test; because we're putting so much effort into obtaining a unique port, this should never be necessary -- in the rare cases that our attempts to obtain a unique port fail, then we absolutely should fail with EADDRINUSE, as the ability to obtain a unique port for the duration of a client/server test is an invariant that we must be able to depend upon. If the invariant is broken, fail immediately (don't mask the problem with SOREUSEADDR). With this patch applied, I can spawn a handful of Python processes and run the entire test suite (without -r, ensuring all tests are run in the same order, which should encourage port conflicts (if there were any)) without any errors*. Doing that now is completely and utterly impossible. [*] Well, almost without error. All the I/O related tests that try and open @test fail. I believe there's still outstanding work to do with this patch with regards to how the intracacies of SOREUSEADDR and SOEXCLUSIVEADDRUSE should be handled in the rest of the stdlib. I'm still thinking about the best approach for this. However, the patch as it currently stands is still quite substantial so I wanted to get it out sooner rather than later for review. (I'll forward this to python-dev@ to try and encourage more eyes from people with far more network-fu than I.) Added file: http://bugs.python.org/file9980/trunk.2550-2.patch

Tracker <report at bugs.python.org> <http://bugs.python.org/issue2550>

Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/tnelson%40onresolve.com

Python-Dev mailing list Python-Dev at python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/greg%40krypto.org -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.python.org/pipermail/python-dev/attachments/20080408/537bb057/attachment-0001.htm

More information about the Python-Dev mailing list