# I am the Watcher. I am your guide through this vast new twtiverse.
#
# Usage:
# https://watcher.sour.is/api/plain/users View list of users and latest twt date.
# https://watcher.sour.is/api/plain/twt View all twts.
# https://watcher.sour.is/api/plain/mentions?uri=:uri View all mentions for uri.
# https://watcher.sour.is/api/plain/conv/:hash View all twts for a conversation subject.
#
# Options:
# uri Filter to show a specific users twts.
# offset Start index for quey.
# limit Count of items to return (going back in time).
#
# twt range = 1 1
# self = https://watcher.sour.is/conv/qhmjjwq
After several hours of debugging in a larger task force yesterday and today, we finally figured out that we must have ran into an XFS bug (seems to work fine on ext4). An ftruncate syscall hung forever and hence the process was caught in an uninterruptible sleep. This was the first time I ever witnessed kill -9 not to "work". But I learned a bunch of new stuff. I never dug this deep into the guts before.
Some of you probably know that /proc/$PID/syscall tells you the current system call the process is executing. And /proc/$PID/stack returns the kernel stack trace. Awesome stuff!
That's a wonderful article on that matter: https://tanelpoder.com/2013/02/21/peeking-into-linux-kernel-land-using-proc-filesystem-for-quickndirty-troubleshooting/