Message894

Author malte
Recipients gabi, malte, patrik
Date 2010-12-17.23:45:01
Content
Not sure if I should classify this as a "bug" since it looks like the code
works, but for Patrik's example it's unusable, and we tend to classify serious
performance issues as bugs too so that they get addressed more quickly that
"feature" or "wish" issues. 

Background:

This is from an old (June 2009) bug report by Patrik (sorry, some context is
missing):

=======================================================================
Attached (domain: crash-test-dummy, problem: bwnc_10_1). It doesn't
crash anymore because I fixed it too (by replaxing "axiom.name" with
"axiom", which produces a totally useless printout like "Removed axiom:
<sas_tasks.SASAxiom instance at 0xb7b3078c>" but at least doesn't crash).

There may be some other problems as well. I tested the the blind search
planner (I think: it's option "ob" to downward/search, right?), and it
claims to have exhausted the space after expanding one node, i.e., the
initial state has no applicable actions). But I don't think that's
right. Also attached is an alternative formulation (bw-no-clear) of the
domain, which I think is equivalent, and can be fed to my parser. Other
planners I've tried (some hsp* variants, ff) explore more than one node
(ff even finds a solution, for both domain formulations).
=======================================================================

This bug does not exist any more; this was fixed when Gabi implemented proper
support for negative conditions. However, Patrik's example now triggers a
performance issue, which I think comes from the "multiply out conditions" code.

Patrik's original 10-block problem fails to translate because it exhausts 3 GB
of memory. It bails out with a memory error in "multiply_out". This is with both
domain versions. I also created a smaller problem (5 blocks) which does
translate after a while, but it generates 25600 axiom rules, which looks a bit
excessive. :-)

So we may need to rethink some of our algorithm choices here.
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crash-test-dummy.pddl malte, 2010-12-17.23:45:01
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2010-12-17 23:45:04maltesetmessageid: <1292625904.99.0.488272175042.issue165@gmail.com>
2010-12-17 23:45:04maltesetrecipients: + malte, gabi, patrik
2010-12-17 23:45:04maltelinkissue165 messages
2010-12-17 23:45:01maltecreate