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Old 2011-06-10, 11:11   #1
D. B. Staple
 
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Nov 2007
Halifax, Nova Scotia

23×7 Posts
Exclamation Error running GGNFS+msieve+factmsieve.py

Hello,

I have been getting crashes during Lattice sieving while running factmsieve.py in linux with 4,8, or 16 cores on numbers in the ~110 digit range.

A tyical crash is preceeded by a drop in the "Total yield:" line in stderr, and the following python error:
ValueError: invalid literal for int() with base 10: ''
On stdout I only get the message "siever terminated"
In the .log I don't get any indication at all that an error was encountered.

In some cases simply restarting the script allows the calculation to continue to completion. Sometimes the script has to be restarted several times, and sometimes it seems that restarting the script does not help.

The crashes are reproducible in the sense that rerunning the same job with the same polynomial seems to crash at a similar spot. However, the crashes are not "exactly the same" in the sense that not all of the output appears identical. I haven't checked the differences carefully yet.

One more note: the numbers in question could be factored using SNFS. I am nevertheless using GNFS, even though SNFS would be faster. Nevertheless, I want to sort out this problem I'm having with GNFS.

I've attached .log, .n, .poly, stderr, and stdout files for a typical crash. Has anyone encountered this error before? Any indication what is going on here?

Best,

Doug
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