robotarmy / weasel

Simply Watch Memory of any process or group of process and do something with them.

Weasel¶ ↑

Simple memory monitor - used in production with passenger to limit uptime of a service using excessive memory - as happens with ruby-1.8.7 on non ree projects

see ./bin/weasel for all the arguments that it takes

Example ¶ ↑

weasel –callback “%x{kill -USR1 #{pid.to_s}}” –watch “Rails:” – num_cycles 3 –num_over_marks 2 –callback_message ‘sending SIGUSR1’ –high_water_mb 440 –delay 1

the above will send sigusr1 (graceful exit) to all the processes matching 'Rails' that run over 440MB 2 out of 3

samples.

Samples are taken a total of 3 times with a delay of 1 second between them.

Put this in a cronjob to run every minute and you have a very simple, robust way to reap overmemory processes.

You can also combine this nicely with services that use daemontools if you don't want to write complex restart / shutdown code.

Contributor¶ ↑

Ben Somers - 1.9 support and production friendly test support

Fin¶ ↑

Copyright © 2010 Curtis Schofield. See LICENSE for details.

weasel's Issues

ps argument does not list all processes

memory_watch.rb:

cmd = "ps x |grep '#{self.watch_string}' |grep -v grep | awk '{print $1}'"

This does not list processes that are run by different user than the one running weasel. I'd rather run weasel as root from crontab and let it kill unicorn workers that are run as www-data.

Should probably be "ps ax". Also you could use sys-proctable gem instead.

It would be great too if weasel said something if it didn't find any processes matching with the watch statement. Also it could process .conf files from something like /etc/weasel.d/ that could look something like:

#unicorn.conf
watch "unicorn_rails worker"
callback %x{kill -QUIT #{pid.to_s}}
num_cycles 3
num_over_marks 2
callback_message "foo foo foo"
high_water_mb 200
delay 1

The example is wrong

Could be because of github formatting, anyways the example should be in the grey box instead of the explanation.

#original
weasel –callback “%x{kill -USR1 #{pid.to_s}}” –watch ‘Rails:’ –num-cycles 3 –num-over-marks 2 –callback-message ‘sending SIGUSR1’ –high-water-mb 440 –delay 1
#should be:
weasel --callback "%x{kill -USR1 #{pid.to_s}}" --watch "Rails:" -- num_cycles 3 --num_over_marks 2 --callback_message 'sending SIGUSR1' --high_water_mb 440 --delay 1

Running the copypasted example causes weasel to sit still for about 3 minutes and return nothing on my installation.