Re: New behavior proposal --halt -% with job killing

[Ole Tange]

On Tue, Apr 21, 2015 at 9:42 PM, Martin d'Anjou
<martin.danjou14@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.

Can we find a better way to express the meaning and which is not
surprising to the user?

> I will attempt to change the code to do this, but so far you have beaten me
> to the punch each time :-)

Showing an example of how it could be implemented is often a good way
for me to get inspired to improve the implementation, so it should not
hold you back.


/Ole