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Sign upImage extraction does not scale with number of WARCs #298
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For reference, image extraction was implemented here: #234 |
ruebot
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Jan 24, 2019
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ruebot commentedJan 23, 2019
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edited
Describe the bug
aut
fails in a variety of ways the more ARCs/WARCs you try to extract images from at a time.To Reproduce
Using this basic extraction script and scaling the number of WARCs per job:
10 WARCs
Results
100 WARCs
Results
(I accidentally ran it twice.)
200 WARCs
Results
500 WARCs
Results
Environment information
Additional context
ulimit
problem ontuna
with what I believe are the default setting.tuna
is also using zfs as a filesystem.rho
over all the files, I was able to extract ~20M images (there should be about ~121M in total), but I ran into a lot of disk space issues even though I had plenty of disk space free, inodes. Might have been an ext4 issue?Expected behavior
I think we're hitting this because of our implementation and extraction script. I believe we're iterating over the entire collection and identifying all the images, and tossing them into the dataframe, then iterating back over that and dumping them out to a tmp dir, then moving it over to the actual place they're supposed to end up. This requires a huge setting for
spark.driver.maxResultSize
. We should examine our implementation and see if it is possible to stream images out as we find them. That should require less overhead.