Hi,
We are running an application called Arc/Info, which is a bunch of
individual executables, a language interpreter and libraries. We have
inherited an "aml" - sort of like a shell script, but its interpreted by
Arc/Info. This particular aml processes small to medium jobs OK, but as soon
as it hits a large job (ie Arc/Info is a GIS package, so it handles
geometric objects, ie points, lines, strings, polygons, a large job is one
with 20k points, each point can have attributes, which are stored in an Info
database) it just runs for days and never seems to get anywhere. The machine
it's running on is an Alpha 200 4/233 with 256mb and about 750mb of swap,
the OS is DU4.0D and the only thing that has been tweeked is the maxusers =
256. We have also run it on a Sun Ultra10 with 256mb with 800mb of swap and
solaris 2.6, it didn't fair much better.
Without tearing the aml apart, which I believe is rather convoluted (doing
lots of attribute lookups, possibly not using indexes into the db's), is
there some things that can be done to track down what may be happening. The
things I was thinking of were
(a) user process limit (64 procs in DU, this doesn't seem to ba a limit that
is being hit as there are no messages in /var/adm/messages to indicate it
couldn't fork a new process)
(b) virtual memory, (there are no messages suggesting that swap is less than
10%)
(c) buffers (perhaps if it is reading a lot of info from db's and running
out of buffers, is that a possibility)
(d) see whether it is io or cpu bound (not sure how to do this, as the
process has been the only one on the machine at the time, it has tended to
have a high cpu value (>80%) in psstat, which I guess is pointing to cpu
bound)
(e) check on the amount of paging(not sure how to do this)
Dennis
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Dennis Macdonell |
Systems Administrator |
AUSLIG | "Any idiot can face
em: mcdonell_at_auslig.gov.au | a crisis - its this
ph: 02 6201 4326 | day-to-day living
fax: 02 6201 4377 | that wears you out"
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Received on Fri Sep 11 1998 - 01:34:35 NZST