Re: Ready to scrap an AS/400

[pytel@xxxxxxxxxx]

>  imho, yes. Isn't the operating system supposed to be in control? And
parcel
>  out resources to various applications? Should it allow any application
to
>  simply take over *all* resources, so that an operator can't even end the
>  application?

By all means OS should always stay in control. In ideal world. But be
reasonable - in a real world it's not humanly possible to foresee all
possible complications.


> When I switched to NT at home, it was a huge relief to have a task
manager that 99%
> of the time allows me to zap offending applications. Why can't OS/400 and
> Unix do that much?

More than once Windows task manager would not let me do anything.
But I see your point. As a mattrer of fact, on OS/400 high-priority console
job (green-screen) can take control in most cases. Of course, if you are
running Ops Nav - then it simply does not have enough priority.
Which also can be fixed, if you take pains to make sure that your system
administrator CA jobs have high priority.

> The only time I've heard of an application taking over like
> that is when someone set their interactive priority to 1.

As a matter of fact, OS/400 dynamic priority scheduler will make sure that
even priority 1 job does not take 100% of CPU - it can take 99% or more,
but still lower priority jobs will do slow progress.
So, this is not a matter of total "lock-up" - with some patience even such
situation can be recovered from without such drastic measures as IPL.

> low priority jobs interfering with higher priority jobs

All the jobs are using the same resources, so low priority jobs will
_always_ interfere with high priority jobs.
BTW, if you have more than one CPU on system, there is much less chance of
this happening.
Of course, if number of offenders is equal to or larger than number of
CPUs, then ...


Alexei Pytel


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