Kill megacron with the megacrond command

[greg-github]

There should be a graceful way to kill megacron, as illustrated by John's issue with getting rid of the daemon.

[greg-github]

Proposal: (I'm going to take at implementing this within the next few days) kill with megacrond -k, edit main.py to take the -k command, and upon that we run read_pid_from_pidfile(/var/run/megacron.pid), then use os.kill(pid,SIGINT).

[johntanner]

Sounds good! I don't know if SIGINT on a single pid will take care of all of the instances (which may be desirable), but do some experimentation!

[umzegher]

I am unable to reproduce this issue. Why doesn't "killall megacrond" work?

[johntanner]

I received the message johns-mbp:megacron johntanner$ sudo killall
megacrond No matching processes were found, also without sudo.

On Wed, Apr 9, 2014 at 7:23 AM, Ben Zeghers [email protected]:

I am unable to reproduce this issue. Why doesn't "killall megacrond" work?

Reply to this email directly or view it on GitHubhttps://github.com//issues/51#issuecomment-39969499
.

[umzegher]

What are the steps to reproduce this issue? If the name of the process
doesn't contain megacrond, then what is it?
On Apr 9, 2014 11:39 AM, "John Tanner" [email protected] wrote:

I received the message johns-mbp:megacron johntanner$ sudo killall
megacrond No matching processes were found, also without sudo.

On Wed, Apr 9, 2014 at 7:23 AM, Ben Zeghers <[email protected]

wrote:

I am unable to reproduce this issue. Why doesn't "killall megacrond"
work?

Reply to this email directly or view it on GitHub<
https://github.com/BigFav/MegaCron/issues/51#issuecomment-39969499>
.

Reply to this email directly or view it on GitHubhttps://github.com//issues/51#issuecomment-39986480
.

[johntanner]

Steps are:

1. sudo megacrontab -e ... enter a crontab ie. * * * * * echo hello >
   /Users/johntanner/Desktop/hello.txt ... save
2. sudo megacrond
3. sudo megacron-status ... observe that 1 worker is up
4. killall megacrond ... No matching processes belonging to you were found
5. sudo killall megacrond ... No matching processes were found
6. Observe how the job still runs every minute.
7. ps aux | grep megacron
   root 93340 0.1 0.0 2467248 1632 ?? S 10:03am
   0:00.40
   /System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
   /usr/local/bin/megacrond
   root 92164 0.0 0.1 2468276 4340 ?? S 11:08pm
   0:03.64
   /System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
   /usr/local/bin/megacrond
   johntanner 93393 0.0 0.0 2423368 184 s001 R+ 10:07am
   0:00.00 grep megacron

NOTE The process belonging to johntanner is probably from an earlier,
unkilled trial.

On Wed, Apr 9, 2014 at 9:59 AM, Ben Zeghers [email protected]:

What are the steps to reproduce this issue? If the name of the process
doesn't contain megacrond, then what is it?

On Apr 9, 2014 11:39 AM, "John Tanner" [email protected] wrote:

I received the message johns-mbp:megacron johntanner$ sudo killall
megacrond No matching processes were found, also without sudo.

On Wed, Apr 9, 2014 at 7:23 AM, Ben Zeghers <[email protected]

wrote:

I am unable to reproduce this issue. Why doesn't "killall megacrond"
work?

Reply to this email directly or view it on GitHub<
https://github.com/BigFav/MegaCron/issues/51#issuecomment-39969499>
.

Reply to this email directly or view it on GitHub<
https://github.com/BigFav/MegaCron/issues/51#issuecomment-39986480>

.

Reply to this email directly or view it on GitHubhttps://github.com//issues/51#issuecomment-39988781
.

[umzegher]

This issue doesn't happen on megacron-one.wmflabs.org. It must be specific to OS X or your system. Does "sudo pkill -f megacrond" work for you?

[johntanner]

That works. I am on Mac OS X Mavericks 10.9.2

On Wed, Apr 9, 2014 at 10:52 AM, Ben Zeghers [email protected]:

This issue doesn't happen on megacron-one.wmflabs.org. It must be
specific to OS X or your system. Does "sudo pkill -f megacrond" work for
you?

Reply to this email directly or view it on GitHubhttps://github.com//issues/51#issuecomment-39995130
.

[johntanner]

I still think we should have a unified command for stopping the daemon. Is
Greg's suggestion not good?

On Wed, Apr 9, 2014 at 11:00 AM, John Tanner [email protected] wrote:

That works. I am on Mac OS X Mavericks 10.9.2

On Wed, Apr 9, 2014 at 10:52 AM, Ben Zeghers [email protected]:

This issue doesn't happen on megacron-one.wmflabs.org. It must be
specific to OS X or your system. Does "sudo pkill -f megacrond" work for
you?

Reply to this email directly or view it on GitHubhttps://github.com//issues/51#issuecomment-39995130
.

[umzegher]

It seems that killall and pkill only match the process name by default on OS X. Since our daemon is running though the Python interpreter the process name is python and megacrond is in the arguments. On Linux it will match the process name or the arguments and the -f flag for pkill will do this on OS X too. I just wanted to know what was causing this issue and why it was only happening sometimes before we decide how to solve it. Given what we now know if you still think that this is the best solution, then go ahead and implement it.

As John mentioned before there is an issue with my daemon implementation that multiple can be run at a time. When multiple start they overwrite the PID file which isn't good. The library seems to have code that throws an error if the file already exists but it will have to be investigated why this isn't working.