Crontab not working from whenever gem

Question

My linux server is running a Rails 4 app with Nginx/unicorn.

I am using the Whenever gem to schedule tasks. Everything was working normally until a couple of days ago when the cron jobs appear to have simply stopped running.

This is in my schedule.rb file:

every 5.minutes do
    runner "Video.send_to_wistia", environment: 'production'
end

This is what I see when I run crontab -l:

# Begin Whenever generated tasks for: myapp
0,5,10,15,20,25,30,35,40,45,50,55 * * * * /bin/bash -l -c 'cd /home/myuser/myapp && bin/rails runner -e production '\''Video.send_to_wistia'\'''
# End Whenever generated tasks for: myapp

I have restarted unicorn. I also made sure to run:

whenever --update-crontab myapp

In my video.rb file, which contains the action that should run, I placed some log code:

   def self.send_to_wistia
        logger.debug( "Sending videos to wistia at #{Time.now}" )
        ...

I've been watching the logs and nothing appears there.

PS: My first instinct was that maybe the site is running in development mode (which the whenever task is not configured to run in) but this does not seem to be the case, because I see now records going into my production database.

Update: As the user for my app, when I run service cron status I get this: cron: unrecognized service. But I'm not sure if this is checking the user's crontab or the system-wide.

Update2: This is what I see when I run pgrep -l cron:

410 crond
582 crond
711 crond
879 crond
1021 crond
1188 crond
1320 crond
1404 crond
1509 crond
1648 crond
1805 crond
1829 crond
1936 crond
2090 crond
2196 crond
2235 crond
2388 crond
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2523 crond
2673 crond
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4375 crond
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4657 crond
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5036 crond
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5609 crond
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5891 crond
5918 crond
6186 crond
6203 crond
6468 crond
6501 crond
6781 crond
6786 crond
7080 crond
7084 crond
7368 crond
7375 crond
7658 crond
7667 crond
7964 crond
7965 crond
8246 crond
8559 crond
8647 crond
8841 crond
8932 crond
9136 crond
9232 crond
9444 crond
9515 crond
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31596 crond
31692 crond
31892 crond
31983 crond
32174 crond
32283 crond
32469 crond
32568 crond
32751 crond

Update 3: I ran ps -ef | grep cron and I get:

root      1404     1  0 Oct31 ?        00:00:00 crond
myappuser    3961  2746  0 10:56 pts/1    00:00:00 grep cron

Update 4: I ran /bin/bash -l -c 'cd /home/clippo/clippo2 && bin/rails runner -e production '\''Video.send_to_wistia'\''' and this is what I see:

/home/myuser/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/runner.rb:53:in `eval': No such file or directory - /home/myuser/myapp/tmp/video_uploads/190 (Errno::ENOENT)
    from /home/myuser/myapp/app/models/video.rb:31:in `new'

This error message is really confusing because that directory DOES exist and always has.

Answer 1

Does your

crontab -l

output match what you have in your schedule file for your whenever gem?

I usually do

whenever -w

any time I make changes to my schedule file and want my crontab updated.

Although it seems like you're having issues getting your actual rb file to run that logger command. you could try editing your schedule.rb to have a set :output like this ->

set :output, "/Users/home/rubylogs/vendorcatalog.log"

every :day, :at => "2:31am" do

command "cd /Users/home/automation/Vendor\ Catalog; parallel_test -n 1 *.rb"

end

The parallel test stuff isn't really relevant but you get the point. See if you get any output when you do it that way? That should tell you whether or not it's running something.

Answer 2

This turned out to be a wild goose chase. The cron probably WAS working all along, but the script its self was erroring out (thanks to @Arsen7 for pointing me in this direction), giving the appearance that it had stopped. If you look closely at the error message under Update 4 above, you'll see...

/home/myuser/myapp/tmp/video_uploads/190

I initially missed the /190, which should be a file name (190.MOV). But it was missing an extension and appearing to be a directory, which does not exist, and caused the whole script to fail.

Answer 3

As a first guess, it could be that your cron daemon has stopped working.

It depends on what type of cron is installed on your system, but I guess that the command pgrep -l cron should list some processes that have "cron" in its names.

Another thing could be to check the system log - usually found in /var/log/messages or nearby. Maybe there are some lines with "cron" in it? A grep -i cron /var/log/messages could be helpful, but it depends on what kind of system logger you have - so the logfile could be different - and how often it is rotated (you have said that the cron stopped working a few days ago).

UPDATE

It looks that your crond is running - even if it has a lot of instances, what might be or might be not unusual.

Now you could follow the fedorqui's advice, and confirm that the line used in the crontab file really works. Maybe it hangs, and thus no new invocations of the cron are created?

If the command works properly, you may want to see the logfiles - either the system log message (something under /var/log directory) or the cron's own logfile (maybe your cron daemon is configured to output its messages into - for example - /var/log/crond).

Usually the cron daemon outputs a log message whenever it runs a task. It also logs when you see or edit the crontab file. These messages may be useful.

If you find no information in the logfiles, then you could just try to restart the cron service. I cannot tell you how to do it, because it depends on the configuration of your server.