On Thu, Apr 23 2015, Ole Tange <o...@tange.dk> wrote: > On Tue, Apr 21, 2015 at 9:42 PM, Martin d'Anjou > <martin.danjo...@gmail.com> wrote: >> Hi Ole, >> >> When I run parametrized tests and the failure rate exceeds a certain >> threshold, I need to kill the remaining running tests and abort with non >> zero and without starting new tests. >> >> GNU Parallel supports --halt with a positive percentage, I was thinking it >> could support this feature when a negative percentage. >> >> Does that sound good? > > So the current --halt X% works similar to --halt 1. As I understand > you want a --halt with % that works similar to --halt 2. > > I am a bit reluctant to let -X% be similar to 2, because it is not > symetrical with --halt -1 and --halt -2 (which look at successes). > > Another idea is to let even percentage be similar to --halt 2, while > odd percentages behave like --halt 1: > > 1-99% (odd numbers) If val% of the jobs fail and minimum 3: Do not > start new jobs, but complete the running jobs including cleanup. The > exit status will be the exit status from the last failing job. > > 2-100% (even numbers) If val% of the jobs fail and minimum 3: Kill > off all jobs immediately and exit without cleanup. The exit status > will be the exit status from the failing job. > > I am not really sure if any of those adhere to the Principle of Least > Astonishment.
Hm, I don't think that would be particularly intuitive. How about allowing --halt be given multiple times, with each invocation overriding certain aspects of the behaviour requested so far. Then one could do --halt 25% --halt 2 with --halt 25% --halt 1 being the same as --halt 25% by itself. Encountering --halt 0 would restore the default behaviour. I really prefer when any command-line option can be overridden (or reset to the default) by a later option - that makes it a lot easier to write wrapper scripts which contain a few default flags but allow the user to tweak these by just appending options. For example in Martin's case, one could have the above --halt 25% --halt 2 hardcoded in whatever script runs the tests, and the script could then support a --no-halt-on-error which would just append --halt 0 to the parallel options (instead of the error-prone process of trimming the current list of options, where one has to be careful with --halt=25% versus --halt 25% etc.). > Can we find a better way to express the meaning and which is not > surprising to the user? Not sure my proposal is better - just thinking out loud. Rasmus
