Pipeline Problems

[Thomas Droege <tdroege2@earthlink.net>]

On the 15th one of the pipelines failed to produce star lists (.cal).  It
did make the collated files (.clt) a real mystery since everything seemed
to be OK.

After consultation with Michael, I again ran the photometry step breaking
the .clt files into chunks.  Everything ran.  Apparently the pipeline was
running out of memory at some stage.  

Later it occurred to me that the computer may have "lost" some memory.   It
had been running a long time since a reboot.  The computer that failed was
my "Wall-Mart" Lindows special.  (Long since reloaded with Mandrake linux) 
It is the slowest of the 6 computers in the pipeline and has the least
memory.  256Mbytes.

It is common for linux computers to lose track of memory?   Is this the
likely problem?  This computer had (I believe) processed larger files
before.  

Along the same lines, from time to time my linux machines will fail to
respond in a Konsole window.  There is a prompt but it does not see
keyboard entry.  The mouse works so I can close the window and open another
one and then everything is normal.  I this OK to do?   Is there a better
way?  Could this be the source of memory loss? (However I don't recall
doing this on the suspect machine running Mandrake 8.2, it seems to happen
more often on the 10.0 machines.) Is there a good way to clear out "dead"
jobs?

Mostly the pipeline runs reliably and it is a pleasure to operate this
project.  The largest chore is to write the CDs at the end of a run with
the images.  This takes an hour and a half or so to write 12+ CDs at this
time of year.  This would be easier if I wrote DVDs but after reading the
NIST report, I think I will stick to the CDR as the most probable to
survive some time.

Tom Droege


Tom  Droege Jennifer Malpass
tdroege2@earthlink.net