MZMcBride added a comment.
Copying @Anomie's comment from https://phabricator.wikimedia.org/T132159: > While investigating https://phabricator.wikimedia.org/T132123, I discovered that responses with lengths near to multiples of 32768 bytes will have their final bytes corrupted. A response with a length exactly 32768 bytes will have the final 8 bytes corrupted (in my test, they are replaced with `27 a5 ae 23 8b 7f 00 00`). A file with length 1–7 bytes less than such a multiple will have the final 7–1 bytes corrupted. > > Steps to reproduce: > > 1. Create a file with a length that is a multiple of 32768 someplace where it will be served by our infrastructure, e.g. using `dd if=/dev/zero of=/srv/mediawiki/w/test.txt bs=1 count=32768` on mw1017. > 2. Fetch the file from the public Internet without using compression, e.g. using `curl --header 'X-Wikimedia-Debug: backend=mw1017.eqiad.wmnet' -v "https://de.wikipedia.org/w/test.txt"` > > I've tested this with backends mw1017, mw1099, and mw2099 (frontend via eqiad) with identical results. Going through different load balancers (e.g. using `curl -k --header 'Host: en.wikipedia.org' --header 'X-Wikimedia-Debug: backend=mw2099.codfw.wmnet' -v "https://text-lb.esams.wikimedia.org/w/test.txt"`) also produces the corruption, but the specific values of the corrupted bytes are different. I did `len(output)` during my testing in https://phabricator.wikimedia.org/T133866#2272654. The bad response (using the exact URL provided in this task) has a length of 32766 bytes, while the good response (using a cache-buster) has a length of 32822 bytes. TASK DETAIL https://phabricator.wikimedia.org/T133866 EMAIL PREFERENCES https://phabricator.wikimedia.org/settings/panel/emailpreferences/ To: BBlack, MZMcBride Cc: Trung.anh.dinh, MZMcBride, Anomie, Yurivict, TerraCodes, Orlodrim, BBlack, akosiaris, zhuyifei1999, elukey, ema, Aklapper, hoo, D3r1ck01, Izno, Wikidata-bugs, aude, Mbch331, Jay8g, jeremyb _______________________________________________ Wikidata-bugs mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikidata-bugs
