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Have `bin/phd stop` look for daemons and warn you about them, or nuke them with some flag
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Sometimes, for whatever reason, daemon processes survive phd stop. After killing daemons we know about, we should run ps auxwww or similar and look for still-living daemons, and warn the user:

WARNING: Some daemons seem to have survived:

  2932  php ./launch_daemon.php PhabricatorGarbageCollectorDaemon --daemonize
        --log=/var/tmp/phd/log/daemons.log --phd=/var/tmp/phd/pid

Use `phd stop --force` to forcibly kill these processes.

Then, with --force, we should kill them.

Event Timeline

epriestley triaged this task as Normal priority.
epriestley added a project: Daemons.
epriestley added a subscriber: epriestley.

To reproduce this easily, do:

phabricator/ $ bin/phd launch nice # launches a "nice" daemon that does nothing

Normally, phd stop should be able to stop this daemon.

To reproduce the problem, launch a daemon and then remove the PID file:

rm -rf /var/tmp/phd/pid/* # or wherever these live on your system

Now, phd stop should fail to find the daemon.

You can launch several "nice" daemons with:

phabricator/ $ ./bin/phd launch 4 nice

What is the correct way to distinguish between Phabricator daemons and other processes in the output from ps auxwww? It seems like you would need a filter that wouldn't delete other processes by mistake.

I think looking for the strings exec_daemon.php or launch_daemon.php is good for now. If you want to be extra paranoid, you could additionally require that --daemonize (keeps it from killing phd debug) and --load-phutil-library= (keeps it from killing scripts which happen to be named exec_daemon.php) be present.

The kill code I mentioned is in PhutilDaemonOverseer->annihilateProcessGroup() (in libphutil/).

  • D5663 added a reasonable-looking way to detect these processes, but bin/phd never got the glue code to call it.
  • This task is otherwise still relevant:
    • Add code in bin/phd stop and bin/phd restart to warn the user that there are processes which look like daemons that don't have corresponding PID files, and that they can use --force to terminate them.
    • With --force, terminate these processes.
    • The steps in should still let you reproduce this in modern phd.
avivey changed the visibility from "All Users" to "Public (No Login Required)".Nov 16 2016, 6:44 PM