RE: System shutting down due to memory overload

[Greg Wilburn <gwilburn@xxxxxxxxxxxxxxxxxxxxxxx>]

Token Ring???
OMG, I just had a flashback to my days of selling twinax gateways (lol, spellchecker doesn't like twinax)

-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Larry "DrFranken" Bolhuis
Sent: Friday, August 5, 2022 10:30 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxxxxxxxx>; Dave <dfx1@xxxxxxxxxxxxxx>
Subject: Re: System shutting down due to memory overload

In my 34 years on the platform I have never seen this happen.

What I HAVE seen happen is that a job crashes due to the demand for 
memory that was not there. That can be ugly for that job of course but 
the system moved on.

The only time I've seen a system almost lock up due to memory demand was 
back in the token ring days when error recovery was looping due to an 
open ring. The system didn't crash by nearly all memory was in the 
*MACHINE pool bringing the rest of the system to its knees. Varying off 
the TR Line brought it back.

Have you actually seen a machine simply shut down because memory was full?

NOTE: This is different from running out of disk space due to the growth 
of temporary storage (paging space ). In that case QSTGLOWACN and 
QSTGLOWLMT will dictate what happens and when.

	- DrF


On 8/5/2022 9:31 AM, Dave wrote:
> Hello,
>
> What happens exactly on the i when a job uses so much memory that the
> system shuts down?
> Is it a controlled shutdown or does it just switch off?
> What protection is available from, for example, a batch test that goes
> wrong and creates too many records in a physical file resulting in a memory
> full situation?
> What protection do you yourselves have from such a scenario (apart from the
> programme responsible using his commonsense :-) ) ?