(manually forwarding from comp.sys.hp.mpe -- gateway not operational?)


Hi list,

(a technical question, if on-topic postings are allowed ;-)

We have a situation on a large N-class (4x 750Mhz, 16 GB memory) where
a couple of jobs using SUPRTOOL to extract data from one or more
databases have a tendency to put fairly heavy memory demand on the
system. The symptoms we see is that the user volume set that holds the
databases shows good throughput (fortunately it has modern LVD disks,
mirrored and a reasonable spindle count), but the memory demand
associated with SUPRTOOL making its way through some of the datasets
(in the 1..n GB size range) results in MPE starting to make room by
writing out memory regions to transient space on the system volume set,
which unfortunately cannot keep up with the I/O demand (fewer spindles,
and older HVD disk array technology) intermittently causing looong disk
queues and response time degradation...

At present, we are trying to avoid the peaks by at least not running
more than one of the "big" SUPRTOOL jobs at the same time, but we
wonder if there are any SUPRTOOL settings that could be helpful to
somehow "throttle" selected jobs to not be as "greedy" for memory as
they are at present (e.g. set makeabsent, set prefetch, or set
privmode).

SUPRTOOL is probably too good at doing its extraction task, at least
for those jobs that have to "coexist peacefully" with all the
interactive users (i.e. not inside a batch time window).

Thanks in advance for any advice or pointers.

Lars.

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