I have a standalone moodle server (ubuntu 18.04, moodle 2.9.1, stack v4.2.1) that I set up a few years ago and have been upgrading (via git) at the beginning of each semester.
I noticed today that the server had long-running maxima processes that were noticeably slowing things down:
# ps auxwwf | grep maxima
www-data 31947 7.6 4.1 577272 509260 ? R Dec01 95:52 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 19407 7.3 8.4 1100632 1033976 ? R Dec01 75:37 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 8451 6.7 8.3 1090240 1024968 ? R Dec01 52:33 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 23076 6.6 8.3 1100492 1031284 ? R Dec01 46:45 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 24494 6.5 4.1 577528 508256 ? R Dec01 46:13 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 7861 6.4 8.3 1100736 1031452 ? R 00:36 40:10 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 10473 6.3 4.1 576908 509108 ? R 00:48 39:13 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 17026 6.3 8.3 1100396 1032052 ? R 01:17 37:05 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 17171 6.3 8.3 1101152 1032020 ? R 01:18 37:02 /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
What I noticed is that the parent process of each of these processes is dead, but the child is still running.By contrast, there were other long-lived processes with the parent still alive:
www-data 30380 0.0 0.0 4628 0 ? S 02:24 0:00 sh -c /usr/bin/maxima 2>&1
www-data 30381 6.2 4.1 576244 506740 ? R 02:24 32:30 \_ /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 5287 0.0 0.0 4628 0 ? S 03:01 0:00 sh -c /usr/bin/maxima 2>&1
www-data 5288 6.2 2.0 316208 246876 ? R 03:01 30:14 \_ /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
www-data 20222 0.0 0.0 4628 0 ? S 09:42 0:00 sh -c /usr/bin/maxima 2>&1
www-data 20223 5.2 3.5 515248 430552 ? R 09:42 4:19 \_ /usr/lib/maxima/5.41.0/binary-gcl/maxima -eval (cl-user::run) -f --
I am a bit mystified about why those children are not being reaped. And, how can I ensure they get reaped?
TIA,
Leo