[Swift-devel] Re: [Swift-user] Resending: I/O errors in swift script

[Mihael Hategan]

> >> Also noted that:
> >>
> >> - the retry logic here did more harm than good.
> > 
> > Can you be more specific?
> 
> In this case there was a script error.  Every retry that wound up on an 
> IA64 host would fail. But there was no feedback on this aspect of the 
> runtime environment.
> 
> I suspect a better default is "stop the workflow on first failure", then 
> let the user re-run till the wf is considered "debugged" and then let 
> the user set how things should be retried.

I think that's an over generalization of a solution to your particular
case. It ignores errors due to sites having problems, which is pretty
standard, and would cause lots of annoyances. Ioan asked for more
retries, and I can understand why. Now you're asking for no retries.

The assumption was this: if there's a problem with the application
invocation, all retries will eventually fail. There is no way to tell
between application failures and site failures (even the exit code may
not be the right indicator). Retries dramatically decrease the odds of
failing the whole workflow because of a bad node/site (although it
depends on the exact initial probability of finding bad nodes). But they
do not change much if the invocation is broken. The application not
being installed properly is, to a certain extent, a site problem, and
chances are that running the same thing on a different site will make it
work.

Perhaps there should be two different sets of settings: one for setting
up the workflow, and one for running it in production mode.

Or, perhaps, the information about the workflow should be organized
better, using interfaces more intuitive than endless streams of loosely
structured text, so that the user can, interactively, explore the
various details of what has happened.

Now, there's retries and there's lazy errors (compute everything that's
possible and only stop after nothing more can be done). You can disable
that. swift -help. I think it's -lazy.errors=false.

Mihael

> 
> - Mike
>